Electric oil pump, housing body portion, and pump cover

Abstract

An electric oil pump a shaft extending in an axial direction, a motor including a rotor that is rotatably fixed to the shaft and a stator, a pump to be driven to pump oil by power of the motor, and a housing accommodating the motor and the pump. The pump includes an inner rotor coupled to the shaft, and an outer rotor surrounding the inner rotor from an outer side in a radial direction. The housing includes a housing body portion made of resin and a metal housing portion made of metal. The housing body portion includes an accommodation recess portion that is recessed toward another side in the axial direction and accommodates the pump, and a stator holding portion that holds the stator. The accommodation recess portion includes a recess portion inner circumferential surface surrounding the pump from the outer side in the radial direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2025-055812 filed on Mar. 28, 2025, and Japanese Patent Application No. 2025-148583 filed on Sep. 8, 2025, the entire contents of each application being incorporated herein by reference.1. FIELD OF THE INVENTION

[0002] The present disclosure relates to electric oil pumps, housings, and pump covers.2. BACKGROUND

[0003] An oil pump has been known that includes a resin motor housing that accommodates a motor having a rotating shaft, and a metal pump case that accommodates a pumping gear rotated by the rotating shaft, wherein the pump case is fixed to the motor housing using a plurality of locking pieces of the motor housing.SUMMARY

[0004] In the above-described oil pump, a difference in linear expansion coefficient is large between the resin motor housing and the metal pump case. Thus, there is a concern that when the temperature of the oil pump varies, a holding force of each of the locking pieces for holding the pump case may greatly vary. Accordingly, in the oil pump, when the temperature of the oil pump varies, the positional accuracy between the center axis of the motor and the center axis of the pumping gear may be compromised. This may result in huge loss of the driving force transmitted from the motor to the pumping gear. Therefore, with the oil pump, the flow rate of the oil discharged from the pump may be reduced.

[0005] An electric oil pump according to an example embodiment of the present disclosure includes a shaft extending in an axial direction, a motor including a rotor that is rotatably fixed to the shaft, and a stator facing the rotor with a gap in a radial direction, a pump to be driven to pump oil by power of the motor, and a housing accommodating the motor and the pump. The pump includes an inner rotor coupled to the shaft on one side in the axial direction and including external teeth, and an outer rotor surrounding the inner rotor from an outer side in the radial direction and including internal teeth meshing with the external teeth. The housing includes a housing body portion made of resin and a metal housing portion made of metal. The housing body portion includes an accommodation recess portion that is recessed from an end portion on one side in the axial direction toward another side in the axial direction and accommodates the pump, and a stator holding portion that holds the stator. The accommodation recess portion includes a recess portion inner circumferential surface surrounding the pump from the outer side in the radial direction. The metal housing portion is at least partially embedded in the housing body portion. The metal housing portion includes a cylindrical circumferential wall portion between the pump and the recess portion inner circumferential surface in the radial direction.

[0006] A housing body portion is made of resin, at least partially accommodates a motor and a pump in a positive displacement electric oil pump, and is welded to a pump cover made of resin, has a cylindrical shape extending in an axial direction, and includes a first welded portion at an end portion in the axial direction, and the first welded portion includes a first welded protrusion portion protruding in the axial direction and welded to a second welded portion of the pump cover.

[0007] A pump cover is made of resin and welded to a housing body portion made of resin, the housing body portion at least partially accommodates a motor and a pump in a positive displacement electric oil pump, the pump cover includes a second welded portion at an end portion in an axial direction, and the second welded portion includes a second welded protrusion portion protruding in the axial direction and welded to a first welded portion of the housing body portion.

[0008] The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a first perspective view illustrating an electric oil pump according to a first example embodiment of the present disclosure.

[0010] FIG. 2 is a cross-sectional view illustrating the electric oil pump according to the first example embodiment.

[0011] FIG. 3 is an enlarged cross-sectional view illustrating a portion of the electric oil pump according to the first example embodiment.

[0012] FIG. 4 is a cross-sectional view illustrating the electric oil pump according to the first example embodiment, taken along IV-IV in FIG. 3.

[0013] FIG. 5 is a second perspective view illustrating the electric oil pump according to the first example embodiment.

[0014] FIG. 6 is a plan view of a pump cover and a bottom plate portion according to the first example embodiment as viewed from the other side in an axial direction.

[0015] FIG. 7 is a perspective view illustrating a metal housing portion according to the first example embodiment.

[0016] FIG. 8 is a perspective view illustrating the bottom plate portion according to the first example embodiment.

[0017] FIG. 9 is a cross-sectional view illustrating the electric oil pump according to the first example embodiment, taken along IX-IX in FIG. 3.

[0018] FIG. 10 is a perspective view illustrating an electric oil pump according to a second example embodiment of the present disclosure.

[0019] FIG. 11 is a cross-sectional view illustrating the electric oil pump according to the second example embodiment.

[0020] FIG. 12 is a first enlarged cross-sectional view partially illustrating a portion of the electric oil pump according to the second example embodiment.

[0021] FIG. 13 is a cross-sectional view illustrating the electric oil pump according to the second example embodiment, taken along VIII-VIII in FIG. 12.

[0022] FIG. 14 is a plan view of a pump cover and a bottom plate portion according to the second example embodiment as viewed from the other side in an axial direction.

[0023] FIG. 15 is a second enlarged cross-sectional view illustrating a portion of the electric oil pump according to the second example embodiment.

[0024] FIG. 16 is a cross-sectional view illustrating the electric oil pump according to the second example embodiment, taken along XVI-XVI in FIG. 12.

[0025] FIG. 17 is a perspective view illustrating a metal housing portion according to the second example embodiment.DETAILED DESCRIPTION

[0026] Hereinafter, electric oil pumps according to example embodiments of the present disclosure will be described with reference to the drawings. The scope of the present disclosure is not limited to the following example embodiments, and can be arbitrarily changed within the scope of the technical ideas of the present disclosure. In the drawings described below, in order to make each configuration easy to understand, the scale, the number, and the like in each structure may be different from those in the actual structure.

[0027] In each drawing, a Z axis is illustrated as appropriate. The direction in which the Z axis extends is the direction in which a rotation axis J of the example embodiments described below extends. The rotation axis J in each diagram is a virtual axis. In the following description, the direction in which the rotation axis J extends, that is, a direction parallel to the Z axis is referred to as an “axial direction”. A side in the axial direction toward which an arrow of the Z axis points (+Z side) is referred to as “one side in the axial direction” or “lower side” and a side in the axial direction opposite to the side toward which the arrow of the Z axis points (−Z side) is referred to as “other side in the axial direction” or “upper side”. In the following description, a radial direction around the rotation axis J is simply referred to as “radial direction” and a circumferential direction around the rotation axis J is simply referred to as “circumferential direction”. Note that each of the upper side and the lower side is merely a name for describing a relative relationship and the like of the respective elements, and the relative positional relationship among the elements may be an arrangement relationship other than the arrangement relationship indicated by these names may be used.

[0028] The circumferential direction is indicated by an arrow θ in each drawing. The side (+θ side) to which the arrow θ points in the circumferential direction is referred to as “one side in the circumferential direction”. The side (−θ side) opposite to the side to which the arrow θ points in the circumferential direction is referred to as “the other side in the circumferential direction”. One side in the circumferential direction is a side of counterclockwise advancement around the rotation axis J as viewed from the upper side. The other side in the circumferential direction is a side of clockwise advancement around the rotation axis J as viewed from the upper side.

[0029] FIG. 1 is a perspective view illustrating an electric oil pump 1 of the present example embodiment. The electric oil pump 1 of the present example embodiment is an electric oil pump that feeds oil as a fluid. The fluid may be another liquid such as water. The electric oil pump 1 is used, for example, to supply oil to an attached body provided to a vehicle or the like. The attached body may be an automatic transmission or a drive device that drives an axle of a vehicle. As illustrated in FIG. 2, the electric oil pump 1 includes a housing 10, a motor 40, a shaft 43, a control device 56, and a pump 60.

[0030] The housing 10 has a substantially cylindrical shape extending in the axial direction. The housing 10 accommodates each of the motor 40, the shaft 43, the control device 56, and the pump 60. The housing 10 includes a housing body portion 11, a lid portion 21, a metal housing portion 25, a pump cover 31, and a bottom plate portion 37. In the present example embodiment, the housing body portion 11, the lid portion 21, and the metal housing portion 25, the pump cover 31, and the bottom plate portion 37 are separate members.

[0031] The housing body portion 11 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The housing body portion 11 accommodates each of the motor 40, the shaft 43, and the pump 60. In the present example embodiment, the housing body portion 11 is made of resin. As a material forming the housing body portion 11, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), or the like can be used. In the present example embodiment, the housing body portion 11 is molded by insert molding using the metal housing portion 25 and a stator 50 (described later) of the motor 40 as inserts. The metal housing portion 25 is at least partially embedded in the housing body portion 11. Thus, the metal housing portion 25 is fixed to the housing body portion 11. Therefore, in the assembly process for the electric oil pump 1, it is not necessary to fix the metal housing portion 25 to the housing body portion 11 using, for example, an adhesive, and thus it is possible to suppress an increase in the number of assembly steps of the electric oil pump 1. The stator 50 is embedded in the housing body portion 11. The housing body portion 11 includes a motor accommodation portion 12, a pump accommodation portion 16, and a rib 20.

[0032] The motor accommodation portion 12 is an upper side portion of the housing body portion 11. The motor accommodation portion 12 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The motor accommodation portion 12 is open on the upper side. The motor accommodation portion 12 accommodates the motor 40. The motor accommodation portion 12 includes a first side wall portion 12a, a stator holding portion 12g, and an attachment portion 14.

[0033] The first side wall portion 12a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The first side wall portion 12a surrounds an upper side portion of each of the motor 40 and the shaft 43 from the outer side in the radial direction. The lid portion 21 is fixed to the upper end of the first side wall portion 12a. The first side wall portion 12a is provided with a first annular groove portion 12c and a first projection portion 12e.

[0034] The first annular groove portion 12c is a groove that is recessed toward the inner side in the radial direction from the surface of the first side wall portion 12a facing the outer side in the radial direction and extends in the circumferential direction. The first annular groove portion 12c extends over the entire circumference in the circumferential direction. An O-ring 91 is fitted in the first annular groove portion 12c. The first projection portion 12e is a projection protruding toward the upper side from the surface of the first side wall portion 12a facing the upper side. The first projection portion 12e extends over the entire circumference in the circumferential direction.

[0035] The stator holding portion 12g has a substantially annular shape that is centered on the rotation axis J. The stator holding portion 12g is provided more on the inner side in the radial direction than the first side wall portion 12a. The stator holding portion 12g is connected to the first side wall portion 12a. The stator 50 (described later) of the motor 40 is embedded in the stator holding portion 12g. Therefore, the housing body portion 11 holds the stator 50. The stator holding portion 12g is provided with a board holding portion 12h.

[0036] The board holding portion 12h has a columnar shape protruding toward the upper side from the surface of the stator holding portion 12g facing the upper side. Although not elaborated in the figures, the stator holding portion 12g is provided with a plurality of the board holding portions 12h. The board holding portions 12h are spaced apart from each other in the circumferential direction.

[0037] The attachment portion 14 protrudes toward the outer side in the radial direction from the surface of the first side wall portion 12a facing the outer side in the radial direction. The attachment portion 14 is provided with a hole portion 14a extending through the attachment portion 14 in the axial direction. As illustrated in FIG. 1, in the present example embodiment, the motor accommodation portion 12 includes two attachment portions 14. The number of the attachment portions 14 included in the motor accommodation portion 12 may be three or more. The attachment portions 14 face each other in the radial direction with the rotation axis J interposed therebetween. A collar portion 14c is inserted in each of the hole portions 14a. Each collar portion 14c is fixed to the inner circumferential surface of the hole portion 14a. Each collar portion 14c is made of metal. As illustrated in FIG. 2, the collar portion 14c has a substantially cylindrical shape extending in the axial direction. When a bolt (not illustrated) is passed through the inside of each collar portion 14c in the axial direction and is fastened into a female screw hole of an attached body (not illustrated), each attachment portion 14 is fixed to the attached body. That is, the electric oil pump 1 is fixed to the attached body.

[0038] As illustrated in FIG. 1, the pump accommodation portion 16 is a lower side portion of the housing body portion 11. The pump accommodation portion 16 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. As illustrated in FIG. 3, the surface of the pump accommodation portion 16 facing the lower side is a lower end portion of the housing body portion 11. The pump accommodation portion 16 has an opening portion 17c that is open on the lower side, that is, one side (+Z side) in the axial direction. The pump accommodation portion 16 accommodates the pump 60. The pump accommodation portion 16 includes a second side wall portion 16a and an annular wall portion 18. The pump accommodation portion 16 is provided with an accommodation recess portion 17. Thus, the housing body portion 11 includes the accommodation recess portion 17.

[0039] The second side wall portion 16a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The second side wall portion 16a surrounds a lower side portion of each of the pump 60 and the shaft 43 from the outer side in the radial direction. The pump cover 31 is fixed to the lower end of the second side wall portion 16a. As illustrated in FIG. 1, the outer diameter of the second side wall portion 16a is smaller than the outer diameter of the first side wall portion 12a. As illustrated in FIG. 3, the second side wall portion 16a is provided with a second projection portion 16c. The second projection portion 16c is a projection that protrudes toward the lower side from the surface of the second side wall portion 16a facing the lower side. The second projection portion 16c extends over the entire circumference in the circumferential direction.

[0040] The accommodation recess portion 17 is a hole that is recessed toward the upper side from the surface of the pump accommodation portion 16 facing the lower side. That is, the accommodation recess portion 17 is a hole that is recessed from the end portion of the housing body portion 11 on the lower side, that is, the one side (+Z side) in the axial direction toward the upper side, that is, the other side (−Z side) in the axial direction. The accommodation recess portion 17 accommodates the pump 60. The accommodation recess portion 17 includes a recess portion inner circumferential surface 17a and a top surface 17e. Thus, the pump accommodation portion 16 includes the top surface 17e.

[0041] The recess portion inner circumferential surface 17a is a surface, of the inner surface of the accommodation recess portion 17, facing the inner side in the radial direction. As illustrated in FIG. 4, the recess portion inner circumferential surface 17a has a substantially circular shape surrounding the rotation axis J. As viewed in the axial direction, the center of the recess portion inner circumferential surface 17a is shifted from the rotation axis J. As illustrated in FIG. 3, the recess portion inner circumferential surface 17a faces the pump 60 in the radial direction. The recess portion inner circumferential surface 17a surrounds the pump 60 from the outer side in the radial direction. The opening portion 17c is the lower end of the recess portion inner circumferential surface 17a.

[0042] The top surface 17e is a surface, of the inner surface of the accommodation recess portion 17, facing the lower side. The top surface 17e is a surface, of the annular wall portion 18, facing the lower side. The top surface 17e is located more on the upper side, that is, the other side (−Z side) in the axial direction than the pump 60. The top surface 17e faces the pump 60 in the axial direction.

[0043] The annular wall portion 18 has a substantially annular shape centered on the rotation axis J. The end portion of the annular wall portion 18 on the outer side in the radial direction is connected to the inner circumferential surface of the second side wall portion 16a over the entire circumference in the circumferential direction. The annular wall portion 18 is provided more on the lower side than the motor 40 and more on the upper side than the pump 60. As described above, the top surface 17e is the surface of the annular wall portion 18 facing the lower side. The annular wall portion 18 is provided with an inner tubular portion 18a, a communication hole portion 18c, an outflow hole 18e, a communication groove portion 18g, and a first groove portion 19. Therefore, the housing body portion 11 includes the communication hole portion 18c. The top surface 17e is provided with each of the communication groove portion 18g and the first groove portion 19.

[0044] The inner tubular portion 18a protrudes toward the upper side from the inner edge of the annular wall portion 18 in the radial direction. The inner tubular portion 18a has a substantially cylindrical shape that is centered on the rotation axis J. The inner circumferential surface of the inner tubular portion 18a is connected to the inner circumferential surface of the annular wall portion 18 in the axial direction.

[0045] The communication hole portion 18c is a hole extending through each of the annular wall portion 18 and the inner tubular portion 18a in the axial direction. The communication hole portion 18c is formed by the inner circumferential surface of the annular wall portion 18 and the inner circumferential surface of the inner tubular portion 18a. As viewed in the axial direction, the communication hole portion 18c has a substantially circular shape centered on the rotation axis J. The communication hole portion 18c connects the inside of the motor accommodation portion 12 and the inside of the accommodation recess portion 17. Thus, the communication hole portion 18c connects the inside of the motor accommodation portion 12 and the inside of the pump accommodation portion 16. The shaft 43 passes through the inside of the communication hole portion 18c in the axial direction. The outflow hole 18e is a hole extending through the annular wall portion 18 in the axial direction. The outflow hole 18e is provided in a portion on the outer side of the annular wall portion 18 in the radial direction.

[0046] The first groove portion 19 is a groove recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the top surface 17e. The first groove portion 19 is open on the lower side. In the present example embodiment, the top surface 17e is provided with two first groove portions 19. The two first groove portions 19 include a first suction-side groove portion 19a and a first discharge-side groove portion 19c.

[0047] As illustrated in FIG. 4, each of the first suction-side groove portion 19a and the first discharge-side groove portion 19c is a substantially arc-shaped groove extending in the circumferential direction as viewed in the axial direction. That is, the first groove portion 19 is a groove extending in the circumferential direction. The first suction-side groove portion 19a and the first discharge-side groove portion 19c are provided at different positions in the circumferential direction. The first suction-side groove portion 19a and the first discharge-side groove portion 19c face each other in the radial direction. More specifically, the first suction-side groove portion 19a and the first discharge-side groove portion 19c face each other in the radial direction, with the rotation axis J interposed therebetween. As illustrated in FIGS. 3 and 4, the first suction-side groove portion 19a overlaps the outflow hole 18e as viewed in the axial direction. As illustrated in FIG. 3, the outflow hole 18e connects the inside of the motor accommodation portion 12 and the inside of the first suction-side groove portion 19a.

[0048] The communication groove portion 18g is a groove recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the top surface 17e. As illustrated in FIG. 4, the communication groove portion 18g extends linearly along the radial direction. The communication groove portion 18g has the end portion, on the inner side in the radial direction, open to the communication hole portion 18c. In the present example embodiment, the end portion of the communication groove portion 18g on the outer side in the radial direction is open to the first discharge-side groove portion 19c. Accordingly, in the present example embodiment, the communication groove portion 18g connects the communication hole portion 18c and the first discharge-side groove portion 19c. That is, the communication groove portion 18g connects the communication hole portion 18c and the first groove portion 19. The end portion of the communication groove portion 18g on the inner side in the radial direction may be open to the annular wall portion 18, and the end portion of the communication groove portion 18g on the outer side in the radial direction may be open to the first suction-side groove portion 19a. In this case, the communication groove portion 18g connects the communication hole portion 18c and the first suction-side groove portion 19a. That is, the communication groove portion 18g connects the communication hole portion 18c and the first groove portion 19.

[0049] As illustrated in FIG. 1, the rib 20 is provided on the outer circumferential surface of the second side wall portion 16a, that is, a surface facing the outer side of the pump accommodation portion 16 in the radial direction. As described above, in the present example embodiment, the housing body portion 11 is made of resin. Therefore, it is difficult to improve the strength of the housing body portion 11 as compared with the case where the housing body portion 11 is made of metal. In contrast, in the present example embodiment, the rib 20 is provided on the surface of the pump accommodation portion 16 facing the outer side in the radial direction, and thus the strength of the housing body portion 11 can be suitably improved. The rib 20 has a plate shape protruding toward the outer side in the radial direction from the pump accommodation portion 16. The plate surface of the rib 20 faces the circumferential direction. The rib 20 extends in the axial direction. The upper end of the rib 20 is connected to the first side wall portion 12a. That is, the rib 20 is connected to the motor accommodation portion 12. The housing body portion 11 includes a plurality of the ribs 20. In the present example embodiment, the housing body portion 11 includes four ribs 20. The number of ribs 20 included in housing body portion 11 may be three or less, or may be five or more. The ribs 20 are disposed at an interval along the circumferential direction. In the present example embodiment, the ribs 20 are disposed at a substantially equal interval along the circumferential direction. Therefore, it is possible to suitably reduce the variation in the strength of the housing body portion 11 in the circumferential direction. As illustrated in FIG. 5, the plurality of ribs 20 include a first rib 20a and a second rib 20c. In the present example embodiment, the plurality of ribs 20 include one first rib 20a and three second ribs 20c. The number of the first ribs 20a and the number of the second ribs 20c included in the plurality of ribs 20 are not limited to those in the present example embodiment.

[0050] The first rib 20a and each second rib 20c are provided on the surface of the pump accommodation portion 16 facing the outer side in the radial direction. Each of the first rib 20a and the second ribs 20c extends in the axial direction. The second ribs 20c and the first rib 20a are spaced apart from each other in the circumferential direction. The first rib 20a has the end portion on the lower side, that is, the one side (+Z side) in the axial direction located more on the lower side than the lower end portion of each of the plurality of second ribs 20c.

[0051] As illustrated in FIG. 2, the lid portion 21 has a substantially cylindrical shape that is centered on the rotation axis J and protrudes in the axial direction. The lid portion 21 is open on the lower side. The lid portion 21 is fixed to the upper end of the housing body portion 11. The lid portion 21 closes the upper side opening of the motor accommodation portion 12. The internal space of the lid portion 21 and the internal space of the motor accommodation portion 12 are connected to each other. The control device 56 is accommodated in the lid portion 21. In the present example embodiment, the lid portion 21 is made of resin. As a material forming the lid portion 21, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), or the like can be used. The lid portion 21 may be made of another material such as a metal material. The lid portion 21 includes a lid circumferential wall portion 22 and a board cover portion 23.

[0052] The lid circumferential wall portion 22 has a substantially cylindrical shape that is centered on the rotation axis J and protrudes in the axial direction. The lid circumferential wall portion 22 surrounds the control device 56 from the outer side in the radial direction. The lid circumferential wall portion 22 is provided with a second annular groove portion 22a. The second annular groove portion 22a is a groove that is recessed toward the upper side from the surface of the lid circumferential wall portion 22 facing the lower side and extends over the entire circumference in the circumferential direction. The first projection portion 12e of the motor accommodation portion 12 is inserted in the second annular groove portion 22a. Therefore, the lid portion 21 is positioned in the radial direction with respect to the housing body portion 11. In the present example embodiment, the lower end of the lid circumferential wall portion 22 and the upper end of the first side wall portion 12a are joined to each other by welding over the entire circumference in the circumferential direction. Therefore, the section between the housing body portion 11 and the lid portion 21 can be suitably sealed, and thus the airtightness of the electric oil pump 1 can be suitably improved. Further, since it is not necessary to separately provide a sealing member such as an O-ring for sealing between the housing body portion 11 and the lid portion 21, it is possible to suppress an increase in the number of components of the electric oil pump 1.

[0053] As illustrated in FIG. 1, the board cover portion 23 has a substantially disk shape centered on the rotation axis J. As illustrated in FIG. 2, the board cover portion 23 is provided more on the upper side than the control device 56. The outer edge of the board cover portion 23 in the radial direction is connected to the upper end of the lid circumferential wall portion 22.

[0054] As illustrated in FIG. 3, the pump cover 31 has a substantially annular shape centered on the rotation axis J. The pump cover 31 is provided more on lower side in the axial direction than the pump 60. The pump cover 31 is fixed to a lower end of the pump accommodation portion 16. The pump cover 31 covers the pump 60 from the lower side. The pump cover 31 closes the accommodation recess portion 17 from the lower side, that is, from the one side (+Z side) in the axial direction. That is, the pump cover 31 closes the opening portion 17c from the lower side. In the present example embodiment, the pump cover 31 is made of resin. As a material forming the pump cover 31, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), or the like can be used. The pump cover 31 may be made of another material such as a metal material. In the present example embodiment, the pump cover 31 is molded by insert molding using the bottom plate portion 37 as an insert. Therefore, the bottom plate portion 37 is fixed to the pump cover 31. Therefore, in the assembly process for the electric oil pump 1, it is not necessary to fix the bottom plate portion 37 to the pump cover 31 using, for example, an adhesive, and thus it is possible to more suitably suppress an increase in the number of assembly steps of the electric oil pump 1. The pump cover 31 includes a cover body portion 32 and a protruding tubular portion 35.

[0055] The cover body portion 32 is an upper side portion of the pump cover 31. The cover body portion 32 has a substantially annular shape centered on the rotation axis J. The cover body portion 32 is provided with a suction port 32a, a discharge hole portion 32b, a discharge port 32c, a third annular groove portion 32e, and a second groove portion 33. Thus, the pump cover 31 is provided with the second groove portion 33. As illustrated in FIG. 5, the cover body portion 32 is provided with a protrusion portion 34. That is, the pump cover 31 is provided with the protrusion portion 34.

[0056] As illustrated in FIG. 3, the suction port 32a is an opening provided in the surface of the cover body portion 32 facing the lower side. The suction port 32a is open on the lower side. Although not elaborated in the figures, the suction port 32a has an arc shape extending in the circumferential direction as viewed in the axial direction. As described later, the suction port 32a is connected to the bottom surface of a second suction-side groove portion 33a. Oil outside the electric oil pump 1 is sucked into the housing 10 through the suction port 32a.

[0057] The discharge hole portion 32b is a hole extending toward the inner side in the radial direction from the surface of the cover body portion 32 facing the outer side in the radial direction. As described later, the end portion of the discharge hole portion 32b on the inner side in the radial direction is connected to a second discharge-side groove portion 33c. As illustrated in FIG. 1, the discharge hole portion 32b is open on the outer side in the radial direction. The discharge port 32c is an opening located at the end portion of the discharge hole portion 32b on the outer side in the radial direction. The discharge port 32c is provided in the surface of the pump cover 31 facing the outer side in the radial direction. As illustrated in FIG. 3, the oil compressed in the pump 60 is discharged to the outside of the electric oil pump 1 through the discharge hole portion 32b and the discharge port 32c.

[0058] The third annular groove portion 32e is a groove that is recessed toward the lower side from the surface of the cover body portion 32 facing the upper side and extends over the entire circumference in the circumferential direction. The second projection portion 16c of the pump accommodation portion 16 is inserted in the third annular groove portion 32e. Thus, the pump cover 31 is positioned in the radial direction with respect to the housing body portion 11. In the present example embodiment, the lower end of the second side wall portion 16a and the upper end of the cover body portion 32 are joined to each other by welding over the entire circumference in the circumferential direction. That is, the pump accommodation portion 16 and the pump cover 31 are joined to each other by welding over the entire circumference in the circumferential direction. Therefore, the section between the housing body portion 11 and the pump cover 31 can be suitably sealed, and thus the airtightness of the electric oil pump 1 can be suitably improved. Further, since it is not necessary to separately provide a sealing member such as an O-ring for sealing between the housing body portion 11 and the pump cover 31, it is possible to suppress an increase in the number of components of the electric oil pump 1.

[0059] The second groove portion 33 is a groove recessed toward the lower side from the surface of the cover body portion 32 facing the upper side. As illustrated in FIG. 6, the second groove portion 33 extends in the circumferential direction. That is, the second groove portion 33 that is recessed toward the lower side, that is, the one side (+Z side) in the axial direction and extends in the circumferential direction is provided in the surface of the pump cover 31 on the upper side, that is, the other side (−Z side) in the axial direction. As illustrated in FIG. 3, the second groove portion 33 is open on the upper side. In the present example embodiment, the cover body portion 32 is provided with two second groove portions 33. Thus, the pump cover 31 is provided with two second groove portions 33. The two second groove portions 33 include the second suction-side groove portion 33a and the second discharge-side groove portion 33c.

[0060] As illustrated in FIG. 6, each of the second suction-side groove portion 33a and the second discharge-side groove portion 33c is an arc-shaped groove extending in the circumferential direction as viewed in the axial direction. That is, the second groove portion 33 is a groove extending in the circumferential direction. The second suction-side groove portion 33a and the second discharge-side groove portion 33c are provided at different positions in the circumferential direction. The second suction-side groove portion 33a and the second discharge-side groove portion 33c face each other in the radial direction. Thus, the two second groove portions 33 face each other in the radial direction. More specifically, the second suction-side groove portion 33a and the second discharge-side groove portion 33c face each other in the radial direction, with the rotation axis J interposed therebetween.

[0061] As illustrated in FIG. 6, the second suction-side groove portion 33a overlaps the suction port 32a as viewed in the axial direction. The inside of the second suction-side groove portion 33a is connected to the suction port 32a. The second suction-side groove portion 33a overlaps the first suction-side groove portion 19a as viewed in the axial direction. As illustrated in FIGS. 4 and 6, the second suction-side groove portion 33a and the first suction-side groove portion 19a have substantially the same shape as viewed in the axial direction.

[0062] As illustrated in FIG. 3, the second discharge-side groove portion 33c is connected to the discharge hole portion 32b. Therefore, the inside of the second discharge-side groove portion 33c is connected to the discharge port 32c through the discharge hole portion 32b. The second discharge-side groove portion 33c overlaps the first discharge-side groove portion 19c as viewed in the axial direction. As illustrated in FIGS. 4 and 6, the second discharge-side groove portion 33c and the first discharge-side groove portion 19c have substantially the same shape as viewed in the axial direction.

[0063] As illustrated in FIGS. 5 and 6, the protrusion portion 34 protrudes toward the outer side in the radial direction from the upper end of the surface of the cover body portion 32 facing the outer side in the radial direction. As viewed in the axial direction, the protrusion portion 34 has a substantially trapezoidal shape with a long side located on the inner side in the radial direction and a short side located on the outer side in the radial direction. The protrusion portion 34 overlaps the first rib 20a as viewed in the axial direction. The protrusion portion 34 is provided with a positioning portion 34a.

[0064] The positioning portion 34a is a hole that is recessed toward the lower side, that is, the one side (+Z side) in the axial direction from the surface of the protrusion portion 34 facing the upper side, that is, the other side (−Z side) in the axial direction. In the present example embodiment, the positioning portion 34a is provided through the protrusion portion 34 in the axial direction. The positioning portion 34a may not be provided through the protrusion portion 34 in the axial direction. As illustrated in FIG. 6, in the present example embodiment, the positioning portion 34a is open on the outer side in the radial direction. That is, the positioning portion 34a is open in the radial direction. The positioning portion 34a may not be open in the radial direction. As illustrated in FIG. 5, a portion of the first rib 20a on the one side in the axial direction is located inside the positioning portion 34a. In the present example embodiment, the positioning portion 34a is fitted with the first rib 20a. Therefore, the positional accuracy of the pump cover 31 in the circumferential direction with respect to the housing body portion 11 can be improved.

[0065] As illustrated in FIG. 3, the protruding tubular portion 35 protrudes toward the lower side from the lower end of the cover body portion 32. The protruding tubular portion 35 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The protruding tubular portion 35 is provided with a fourth annular groove portion 35a. The fourth annular groove portion 35a is a groove that is recessed toward the inner side in the radial direction from the surface of the protruding tubular portion 35 facing the outer side in the radial direction and extends in the circumferential direction. The fourth annular groove portion 35a extends over the entire circumference in the circumferential direction. An O-ring 92 is fitted in the fourth annular groove portion 35a.

[0066] The metal housing portion 25 is accommodated in the housing body portion 11. As described above, the metal housing portion 25 is fixed to the housing body portion 11. As described above, the metal housing portion 25 is at least partially embedded in the housing body portion 11. In the present example embodiment, the metal housing portion 25 is made of metal. As a material forming the metal housing portion 25, aluminum, stainless steel, or the like can be used. As described above, in the present example embodiment, the housing body portion 11 is made of resin. Therefore, the linear expansion coefficient of the metal housing portion 25 is smaller than the linear expansion coefficient of the housing body portion 11. As illustrated in FIG. 7, the metal housing portion 25 includes a circumferential wall portion 26, a top wall portion 27, and a tubular portion 29.

[0067] The circumferential wall portion 26 has a tubular shape extending in the axial direction. More specifically, the circumferential wall portion 26 has a substantially cylindrical shape surrounding the rotation axis J. As illustrated in FIG. 4, as viewed in the axial direction, the center of the circumferential wall portion 26 substantially matches the center of the recess portion inner circumferential surface 17a. As illustrated in FIG. 3, the circumferential wall portion 26 is open on the lower side. The circumferential wall portion 26 is disposed in the accommodation recess portion 17. The circumferential wall portion 26 is fixed to the recess portion inner circumferential surface 17a. The circumferential wall portion 26 has a portion on the outer side in the radial direction embedded in the second side wall portion 16a. The circumferential wall portion 26 surrounds the pump 60 from the outer side in the radial direction. In the radial direction, the circumferential wall portion 26 is between the pump 60 and the recess portion inner circumferential surface 17a. The upper end of the circumferential wall portion 26 is in contact with the top surface 17e. The lower end of the circumferential wall portion 26 is located at substantially the same position as the lower end of the pump accommodation portion 16 in the axial direction.

[0068] As illustrated in FIG. 7, the top wall portion 27 has a substantially annular plate shape expanding in the radial direction. The top wall portion 27 has a plate shape that expands toward the outer side in the radial direction from the end portion of the tubular portion 29 on the lower side, that is, the one side (+Z side) in the axial direction. The top wall portion 27 surrounds the rotation axis J. The end portion of the circumferential wall portion 26 on the upper side, that is, the other side (−Z side) in the axial direction is connected to the end portion of the top wall portion 27 on the outer side in the radial direction over the entire circumference in the circumferential direction. Therefore, in the present example embodiment, the circumferential wall portion 26 and the top wall portion 27 are integrally formed, whereby the number of components of the metal housing portion 25 can be reduced as compared with a case where the circumferential wall portion 26 and the top wall portion 27 are separate members. Therefore, it is possible to suppress an increase in the manufacturing steps for the electric oil pump 1.

[0069] As illustrated in FIG. 3, the top wall portion 27 is disposed in the accommodation recess portion 17. That is, the top wall portion 27 is disposed in the pump accommodation portion 16. An upper side portion of the top wall portion 27 is embedded in the annular wall portion 18. The top wall portion 27 is fixed to the top surface 17e. The top surface 17e is located more on the upper side than the top wall portion 27 and faces the top wall portion 27 in the axial direction. The surface of the top wall portion 27 facing the lower side is located more on the lower side than the top surface 17e. The top wall portion 27 is between the pump 60 and the top surface 17e in the axial direction. As illustrated in FIG. 7, the top wall portion 27 is provided with the first through hole 28 and a second notch portion 27a.

[0070] The first through hole 28 is a hole extending through the top wall portion 27 in the axial direction. In the present example embodiment, the top wall portion 27 is provided with two first through holes 28. The two first through holes 28 include a first suction-side through hole 28a and a first discharge-side through hole 28c.

[0071] As viewed in the axial direction, each of the first suction-side through hole 28a and the first discharge-side through hole 28c has a substantially arc shape extending in the circumferential direction. That is, the first through hole 28 is a hole extending in the circumferential direction. The first suction-side through hole 28a and the first discharge-side through hole 28c are provided at different positions in the circumferential direction. The first suction-side through hole 28a and the first discharge-side through hole 28c face each other in the radial direction. More specifically, the first suction-side through hole 28a and the first discharge-side through hole 28c face each other in the radial direction with the rotation axis J interposed therebetween.

[0072] As illustrated in FIG. 4, the first suction-side through hole 28a surrounds the first suction-side groove portion 19a as viewed in the axial direction. Therefore, the first suction-side through hole 28a at least partially overlaps the first suction-side groove portion 19a. That is, the first through hole 28 at least partially overlaps the first groove portion 19. Therefore, as illustrated in FIG. 3, the inside of the first suction-side groove portion 19a is connected to the inside of the accommodation recess portion 17 through the first suction-side through hole 28a. The top surface 17e is partially exposed on the lower side through the first suction-side through hole 28a.

[0073] As illustrated in FIG. 4, the first discharge-side through hole 28c surrounds the first discharge-side groove portion 19c as viewed in the axial direction. Therefore, the first discharge-side through hole 28c at least partially overlaps the first discharge-side groove portion 19c. That is, the first through hole 28 at least partially overlaps the first groove portion 19. Therefore, as illustrated in FIG. 3, the inside of the first discharge-side through hole 19c is connected to the inside of the accommodation recess portion 17 through the first discharge-side groove portion 28c. As described above, the inside of the first suction-side groove portion 19a is connected to the inside of the accommodation recess portion 17 through the first suction-side through hole 28a. Accordingly, the inside of the first groove portion 19 is connected to the inside of the accommodation recess portion 17 through the first through hole 28. The top surface 17e is partially exposed on the lower side through the first discharge-side through hole 28c.

[0074] As illustrated in FIG. 7, the second notch portion 27a is a notch extending through the top wall portion 27 in the axial direction. The second notch portion 27a extends in the radial direction. In the present example embodiment, one end of the second notch portion 27a, which is the end portion on the outer side in the radial direction, is connected to the first discharge-side through hole 28c. That is, one end of the second notch portion 27a is connected to the first through hole 28. The second notch portion 27a may have one end on the outer side in the radial direction connected to the first suction-side through hole 28a. The second notch portion 27a has the other end that is the end portion on the inner side in the radial direction reaching the inner edge of the top wall portion 27 in the radial direction. Thus, the second notch portion 27a opens on the inner side in the radial direction. As illustrated in FIGS. 3 and 4, the communication groove portion 18g of the annular wall portion 18 at least partially overlaps the second notch portion 27a as viewed in the axial direction. Therefore, the inside of the accommodation recess portion 17 and the inside of the communication groove portion 18g are connected through the second notch portion 27a.

[0075] As illustrated in FIG. 7, the tubular portion 29 has a tubular shape extending toward the upper side, that is, the other side (−Z side) in the axial direction from the inner edge of the top wall portion 27 in the radial direction. More specifically, the top wall portion 27 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. As illustrated in FIG. 3, the tubular portion 29 is disposed in the communication hole portion 18c. The shaft 43 passes through the inside of the tubular portion 29 in the axial direction. The tubular portion 29 is between the shaft 43 and the inner circumferential surface of the communication hole portion 18c in the radial direction. The shaft 43 is supported by the tubular portion 29 to be rotatable about the rotation axis J. Therefore, since it is possible to suppress a direct contact between the shaft 43 and the communication hole portion 18c made of resin, wearing of the communication hole portion 18c can be suppressed while the electric oil pump 1 is operating. As illustrated in FIG. 7, the tubular portion 29 is provided with a first notch portion 29a.

[0076] The first notch portion 29a is a notch extending through part of the tubular portion 29 in the circumferential direction, in the radial direction. The first notch portion 29a extends in the axial direction. The lower end of the first notch portion 29a reaches the lower end of the tubular portion 29. Therefore, the first notch portion 29a is open on the lower side, that is, the one side (+Z side) in the axial direction. Therefore, as illustrated in FIG. 3, the inside of the tubular portion 29 is connected to the inside of the accommodation recess portion 17 through the first notch portion 29a. That is, the inside of the tubular portion 29 is connected to the inside of the pump accommodation portion 16 through the first notch portion 29a.

[0077] As illustrated in FIG. 7, the other end which is the end portion of the second notch portion 27a on the inner side in the radial direction, is connected to the lower end of the first notch portion 29a. As described above, one end of the second notch portion 27a is connected to the first discharge-side through hole 28c. As described above, the inside of the first discharge-side through hole 28c is connected to the inside of the accommodation recess portion 17 through the first discharge-side groove portion 19c. Thus, as illustrated in FIG. 3, the inside of the tubular portion 29 is connected to the inside of the first discharge-side groove portion 19c and the inside of the accommodation recess portion 17 through the second notch portion 27a and the first notch portion 29a. As illustrated in FIG. 4, the inside of the first notch portion 29a is connected to the inside of the communication groove portion 18g. As described above, the communication groove portion 18g connects the communication hole portion 18c and the first discharge-side groove portion 19c. Therefore, as illustrated in FIG. 3, the inside of the tubular portion 29 is connected to the inside of the first discharge-side groove portion 19c and the inside of the accommodation recess portion 17 through the second notch portion 27a, the communication groove portion 18g, and the first notch portion 29a.

[0078] As illustrated in FIG. 8, the bottom plate portion 37 has a substantially annular plate shape expanding in the radial direction. The bottom plate portion 37 surrounds the rotation axis J. As illustrated in FIG. 3, the bottom plate portion 37 is fixed to the surface of the pump cover 31 on the upper side, that is, the other side (−Z side) in the axial direction. The bottom plate portion 37 is provided more on the lower side than the pump 60. The bottom plate portion 37 faces the pump 60 in the axial direction. In the present example embodiment, the bottom plate portion 37 is in contact with the circumferential wall portion 26 of the metal housing portion 25 in the axial direction. Therefore, it is possible to suppress direct contact between each of an inner rotor 61 and an outer rotor 62 from coming into direct contact and the pump cover 31 made of resin. The bottom plate portion 37 may face the circumferential wall portion 26 with a gap in between in the axial direction. The end portion of the bottom plate portion 37 on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion 26. In the present example embodiment, the bottom plate portion 37 is made of metal. As a material forming the bottom plate portion 37, aluminum, stainless steel, or the like can be used. As illustrated in FIG. 8, the bottom plate portion 37 is provided with a plurality of hole portions 37a and a second through hole 38.

[0079] Each of the hole portions 37a is a hole extending through the bottom plate portion 37 in the axial direction. In the present example embodiment, the bottom plate portion is provided with six hole portions 37a. The hole portions 37a are provided at a substantially equal interval along the circumferential direction. Although not elaborated in the figures, the pump cover 31 partially enters each of the hole portions 37a. Therefore, it is possible to suitably suppress the variation of the position in the radial direction and the position in the circumferential direction of the bottom plate portion 37 with respect to the pump cover 31, and to increase the holding force of the pump cover 31 for holding the bottom plate portion 37.

[0080] The second through hole 38 is a hole extending through the bottom plate portion 37 in the axial direction. In the present example embodiment, the bottom plate portion 37 is provided with two second through holes 38. The two second through holes 38 include a second suction-side through hole 38a and a second discharge-side through hole 38c.

[0081] As viewed in the axial direction, each of the second suction-side through hole 38a and the second discharge-side through hole 38c has a substantially arc shape extending in the circumferential direction. That is, the second through hole 38 is a hole extending in the circumferential direction. The second suction-side through hole 38a and the second discharge-side through hole 38c are provided at different positions in the circumferential direction. The second suction-side through hole 38a and the second discharge-side through hole 38c face each other in the radial direction. More specifically, the second suction-side through hole 38a and the second discharge-side through hole 38c face each other in the radial direction with the rotation axis J interposed therebetween.

[0082] As illustrated in FIG. 6, the second suction-side through hole 38a surrounds the second suction-side groove portion 33a as viewed in the axial direction. Therefore, the second suction-side through hole 38a at least partially overlaps the second suction-side groove portion 33a. That is, the second through hole 38 at least partially overlaps the second groove portion 33. Therefore, as illustrated in FIG. 3, the inside of the second suction-side groove portion 33a is connected to the inside of the accommodation recess portion 17 through the second suction-side through hole 38a.

[0083] As illustrated in FIG. 6, the second discharge-side through hole 38c surrounds the second discharge-side groove portion 33c as viewed in the axial direction. Therefore, the second discharge-side through hole 38c at least partially overlaps the second discharge-side groove portion 33c. That is, the second through hole 38 at least partially overlaps the second groove portion 33. Therefore, as illustrated in FIG. 3, the inside of the second discharge-side groove portion 33c is connected to the inside of the accommodation recess portion 17 through the second discharge-side through hole 38c. As described above, the inside of the second suction-side groove portion 33a is connected to the inside of the accommodation recess portion 17 through the second suction-side through hole 38a. Accordingly, the inside of the second groove portion 33 is connected to the inside of the accommodation recess portion 17 through the second through hole 38.

[0084] As illustrated in FIG. 2, the motor 40 is accommodated in the housing body portion 11. More specifically, the motor 40 is accommodated in the motor accommodation portion 12. In the axial direction, the motor 40 is provided more on the lower side in the axial direction than the control device 56 and more on the upper side in the axial direction than the pump 60. The motor 40 includes a rotor 41 and the stator 50.

[0085] The rotor 41 is rotatable. In the present example embodiment, the rotor 41 is rotatable about the rotation axis J. The rotor 41 may be rotatable about a virtual axis extending in the axial direction different from the rotation axis J. The rotor 41 includes a rotor core 41a and a magnet 41b. The rotor core 41a has a substantially annular shape centered on the rotation axis J. The magnet 41b is fixed to the rotor core 41a.

[0086] The stator 50 is provided more on the outer side in the radial direction than the rotor 41. The stator 50 faces the rotor 41 in the radial direction with a gap in between. As described above, in the present example embodiment, the stator 50 is embedded inside the stator holding portion 12g. Therefore, the housing body portion 11 holds the stator 50. The stator 50 includes a stator core 51, an insulator 52, and a coil portion 53.

[0087] The stator core 51 surrounds the rotor core 41a from the outer side in the radial direction. The stator core 51 includes a core back portion 51a having a substantially annular shape, and a plurality of teeth portions 51b protruding toward the inner side in the radial direction from an inner circumferential surface of the core back portion 51a. Although not elaborated in the figures, the plurality of teeth portions 51b are disposed at an interval in the circumferential direction. The coil portion 53 is wound around the teeth portions 51b via the insulator 52. The coil portion 53 is formed of a wound coil wire. Although not elaborated in the figures, the coil portion 53 is electrically connected to the control device 56. The control device 56 supplies current to the coil portion 53.

[0088] The shaft 43 has a substantially columnar shape extending in the axial direction. In the present example embodiment, the shaft 43 has a substantially columnar shape that is centered on the rotation axis J and extends in the axial direction. The shaft 43 may be centered on a virtual axis extending in an axial direction different from the rotation axis J, and extend in the axial direction. The shaft 43 extends across the motor accommodation portion 12 and the pump accommodation portion 16. The shaft 43 has an upper side portion disposed in the motor accommodation portion 12. The upper side portion of the shaft 43 passes through the inside of the rotor core 41a in the axial direction. The rotor core 41a is fixed to the outer circumferential surface of the shaft 43. Thus, the rotor 41 is fixed to the shaft 43. Therefore, the shaft 43 is rotatable together with the rotor 41. A portion of the shaft 43 on the center side in the axial direction passes through the inside of the communication hole portion 18c of the housing body portion 11 and the inside of the tubular portion 29 of the metal housing portion 25 in the axial direction. As described above, the tubular portion 29 is between the shaft 43 and the inner circumferential surface of the communication hole portion 18c. The shaft 43 is supported by the tubular portion 29 to be rotatable about the rotation axis J. The shaft 43 has a lower side portion disposed in the pump accommodation portion 16. The lower side portion of the shaft 43 is coupled to the pump 60. Thus, the rotational torque of the rotor 41 is transmitted to the pump 60 through the shaft 43.

[0089] The control device 56 generates current to be supplied to the coil portion 53 and supplies the current to the coil portion 53. Thus, the control device 56 controls the operation of the electric oil pump 1. The control device 56 includes a circuit board 57.

[0090] The circuit board 57 has a plate shape spreading in a direction orthogonal to the axial direction. The circuit board 57 is held by the plurality of board holding portions 12h of the housing body portion 11. A plurality of electronic components are mounted on the circuit board57. The plurality of electronic components include a plurality of power semiconductor elements such as an insulated gate bipolar transistor (IGBT) and a metal-oxide-semiconductor field-effect transistor (MOSFET), a plurality of capacitors, a plurality of resistance elements, and the like. The circuit board 57 is electrically connected to each of an external power supply (not illustrated) and the coil portion 53. The circuit board 57 generates current having a predetermined waveform from current supplied by an external power supply, and supplies the generated current to the coil portion 53. When the coil portion 53 is supplied with current, each of the rotor 41 and the shaft 43 rotates about the rotation axis J.

[0091] The pump 60 is accommodated in the housing body portion 11. More specifically, the pump 60 is accommodated in the pump accommodation portion 16. The pump 60 is accommodated in the metal housing portion 25. As described above, the circumferential wall portion 26 surrounds the pump 60 from the outer side in the radial direction. The top wall portion 27 faces the pump 60 in the axial direction. The pump 60 is coupled to the end portion of the shaft 43 on the lower side, that is, the one side (+Z side) in the axial direction. The pump 60 is driven by the power from the motor 40 to suck oil from the outside of the electric oil pump 1, and compresses the sucked oil to discharge the oil to the outside of the electric oil pump 1. The pump 60 is driven by the power from the motor 40 to pump the oil. The pump 60 of the present example embodiment is a trochoid pump. That is, the electric oil pump 1 of the present example embodiment is a positive displacement electric oil pump. In the present example embodiment, the pump 60 is made of metal. The pump 60 includes the inner rotor 61 and the outer rotor 62.

[0092] The inner rotor 61 extends in the axial direction, and has an annular shape as viewed in the axial direction. A portion of the shaft 43 on the lower side is inserted in the inner rotor 61. The shaft 43 is fixed to the inner circumferential surface of the inner rotor 61. Therefore, the inner rotor 61 is coupled to the lower side, that is, the one side (+Z side) in the axial direction of the shaft 43. The power from the rotor 41 is transmitted to the inner rotor 61. Thus, the inner rotor 61 can be rotated about the rotation axis J. In addition, the inner circumferential surface of the inner rotor 61 and the shaft 43 do not need to be firmly fixed to each other. The inner circumferential surface (inner diameter) of the inner rotor 61 and the outer diameter of the shaft 43 can each have a flat surface portion formed by machining. The inner circumferential surface (inner diameter) of the inner rotor 61 and the shaft 43 may be inserted by clearance fit such that the flat surface portion of the inner circumferential surface (inner diameter) of the inner rotor 61 and the flat surface portion of the outer diameter of the shaft 43 face each other. With this configuration, it is possible to transmit the power of the rotor 41 to the inner rotor 61 while improving the assembly workability of the inner rotor 61 and the shaft 43. Further, by using a retaining ring, it is possible to suppress relative positional deviation between the inner rotor 61 and the shaft 43 in the axial direction.

[0093] The outer rotor 62 is provided more on the outer side in the radial direction than the inner rotor 61. The outer rotor 62 has an annular shape to surround the inner rotor 61 from the outer side in the radial direction. A gap is provided between the outer rotor 62 and the circumferential wall portion 26. The outer circumferential surface of the outer rotor 62 may partially come into contact with the inner circumferential surface of the circumferential wall portion 26. During operation of the electric oil pump 1, oil is interposed between the outer rotor 62 and the circumferential wall portion 26.

[0094] Each of the inner rotor 61 and the outer rotor 62 has a trochoid tooth profile (not illustrated) as illustrated in FIG. 9. The inner rotor 61 has a plurality of external teeth 61a protruding toward the outer side in the radial direction. The outer rotor 62 has a plurality of internal teeth 62a that protrude toward the inner side in the radial direction and mesh with the external teeth 61a. When the inner rotor 61 rotates integrally with the shaft 43 about the rotation axis J, the outer rotor 62 eccentrically rotates about the rotation axis J while sliding on the inner circumferential surface of the circumferential wall portion 26.

[0095] The inside of the second suction-side groove portion 33a and the inside of the first suction-side groove portion 19a are connected in the axial direction via a gap G between the inner rotor 61 and the outer rotor 62, the first suction-side through hole 28a, and the second suction-side through hole 38a as illustrated in FIG. 3. In the following description, the internal space of the second suction-side groove portion 33a, the gap G, and the first suction-side groove portion 19a connected to each other are referred to as a suction chamber A1. The suction chamber A1 is connected to the suction port 32a.

[0096] The inside of the second discharge-side groove portion 33c and the inside of the first discharge-side groove portion 19c are connected in the axial direction via the gap G between the inner rotor 61 and the outer rotor 62, the first discharge-side through hole 28c, and the second discharge-side through hole 38c. In the following description, the internal space of the second discharge-side groove portion 33c, the gap G, and the internal space of the first discharge-side groove portion 19c connected to each other, are referred to as a compression chamber A2. The compression chamber A2 is connected to the discharge port 32c via the discharge hole portion 32b.

[0097] During operation of the electric oil pump 1, the gap G between the inner rotor 61 and the outer rotor 62 moves around the rotation axis J due to rotation of the inner rotor 61 and the outer rotor 62. Therefore, when the pressure in the suction chamber A1 drops, the oil flows into the suction chamber A1 through the suction port 32a as indicated by an arrow F1 in FIG. 3. More specifically, although not elaborated in the figures, the oil that has flowed into the second suction-side groove portion 33a through the suction port 32a flows through the inside of the second suction-side groove portion 33a in the circumferential direction and is sucked into the gap G via the second suction-side through hole 38a. The oil sucked into the gap G partially flows into the first suction-side groove portion 19a through the first suction-side through hole 28a. The oil that has flowed into the first suction-side groove portion 19a flows through the inside of the first suction-side groove portion 19a in the circumferential direction and is sucked into the gap G again.

[0098] When the gap G moves in the circumferential direction due to the rotation of the inner rotor 61 and the outer rotor 62, the oil moves from the suction chamber A1 to the compression chamber A2 as indicated by an arrow F2 in FIG. 3. Although not elaborated in the figures, the oil sucked into the gap G partially flows into the first discharge-side groove portion 19c through the first discharge-side through hole 28c. As described above, the oil sucked from the suction port 32a partially flows into the first suction-side groove portion 19a through the first suction-side through hole 28a. Thus, the oil pumped by the pump 60 passes through the first through hole 28. The oil that has flowed into the first discharge-side groove portion 19c flows through the first discharge-side groove portion 19c in the circumferential direction and is sucked into the gap G again. As described above, the oil that has flowed into the first suction-side groove portion 19a flows in the circumferential direction inside the first suction-side groove portion 19a. Thus, the oil pumped by the pump 60 flows in the first groove portion 19. The oil sucked into the gap G flows into the second discharge-side groove portion 33c via the second discharge-side through hole 38c. The oil that has flowed into the second discharge-side groove portion 33c flows in the circumferential direction inside the second discharge-side groove portion 33c. Thus, when the pressure of the oil in the compression chamber A2 rises, as indicated by an arrow F3 in FIG. 3, the oil in the compression chamber A2 is pumped to the outside of the electric oil pump 1 through the discharge hole portion 32b and the discharge port 32c. Thus, the electric oil pump 1 supplies oil to an attached body not illustrated.

[0099] As described above, in the present example embodiment, in the suction chamber A1, the oil flows into each of the first suction-side groove portion 19a and the second suction-side groove portion 33a. Therefore, a force toward the lower side received from the oil inside the first suction-side groove portion 19a and a force toward the upper side received from the oil inside the second suction-side groove portion 33a are applied to the pump 60. In the present example embodiment, in the compression chamber A2, the oil flows into each of the first discharge-side groove portion 19c and the second discharge-side groove portion 33c. Therefore, a force toward the lower side received from the oil inside the first discharge-side groove portion 19c and a force toward the upper side received from the oil inside the second discharge-side groove portion 33c are applied to the pump 60. Therefore, a force toward the lower side received from the oil inside the first groove portion 19 and a force toward the upper side received from the oil inside the second groove portion 33 are applied to the pump 60. Therefore, in the present example embodiment, the pump 60 can be rotated in a state where the force of the oil is applied to the pump 60 from both sides in the axial direction. Therefore, while the electric oil pump 1 is operating, vibration of the inner rotor 61 and the outer rotor 62 can be suppressed.

[0100] As described above, the inside of the tubular portion 29 is connected to the inside of the pump accommodation portion 16 through the first notch portion29a. As described above, the inside of the tubular portion 29 is connected to the inside of the first discharge-side groove portion 19c and the inside of the accommodation recess portion 17 through the second notch portion 27a, the communication groove portion 18g, and the first notch portion 29a. Therefore, as indicated by an arrow F4 in FIG. 3, the oil sucked into the gap G and the oil inside the first discharge-side groove portion 19c partially flow into the tubular portion 29 and flow toward the upper side between the shaft 43 and the tubular portion 29. Therefore, oil can be supplied to a section between the shaft 43 and the tubular portion 29. Accordingly, the shaft 43 and the tubular portion 29 can be suitably lubricated by the oil, and thus the frictional force between the shaft 43 and the tubular portion 29 can be reduced. As indicated by the arrow F4 in FIG. 3, the oil flowing toward the upper side between the shaft 43 and the tubular portion 29 flows into the motor accommodation portion 12. Therefore, the oil can be supplied to the inside of the motor accommodation portion 12.

[0101] As described above, in the present example embodiment, each of the second notch portion 27a and the communication groove portion 18g is connected to the first discharge-side groove portion 19c. As described above, the pressure of the oil in the compression chamber A2 is high. Accordingly, in the present example embodiment, the oil can flow into the tubular portion 29 from the first discharge-side groove portion 19c at a high flow rate. Therefore, the shaft 43 and the tubular portion 29 can be suitably lubricated by the oil, and the amount of oil flowing into the motor accommodation portion 12 can be increased. Each of the second notch portion 27a and the communication groove portion 18g may be connected to the first suction-side groove portion 19a. Also in this case, the oil can flow into the tubular portion 29 from the first suction-side groove portion 19a, so that the shaft 43 and the tubular portion 29 can be lubricated by the oil, and the oil can be supplied to the motor accommodation portion 12. That is, with the second notch portion 27a and the communication groove portion 18g each connected to the first groove portion 19, the shaft 43 and the tubular portion 29 can be lubricated with the oil, and the oil can be supplied to the motor accommodation portion 12.

[0102] The rotation of the rotor 41 causes the oil that has flowed into the motor accommodation portion 12 to circulate inside the motor accommodation portion 12, and cool each of the motor 40 and the control device 56. As a result, excessive rise in temperature of each of the motor 40 and the control device 56 can be suppressed, whereby the motor 40 and the control device 56 can operate with improved stability.

[0103] As described above, the outflow hole 18e connects the inside of the motor accommodation portion 12 and the inside of the first suction-side groove portion 19a. Therefore, when the pressure in the suction chamber A1 drops while the electric oil pump 1 is operating, the oil circulating in the motor accommodation portion 12 partially flows into the first suction-side groove portion 19a through the outflow hole 18e as indicated by an arrow F5 in FIG. 3. The oil that has flowed into the first suction-side groove portion 19a is pumped to the outside of the electric oil pump 1 through the discharge port 32c, together with the oil that has flowed into the suction chamber A1 through the suction port 32a.

[0104] The electric oil pump 1 according to the present example embodiment includes: the shaft 43 extending in the axial direction; the motor 40 including the rotor 41 that is rotatably fixed to the shaft 43, and the stator 50 facing the rotor 41 with a gap in the radial direction; the pump 60 driven to pump oil by power of the motor 40; and the housing 10 accommodating the motor 40 and the pump 60, wherein the pump 60 includes the inner rotor 61 coupled to the shaft 43 on the lower side, that is, the one side (+Z side) in the axial direction and having the external teeth 61a, and the outer rotor 62 surrounding the inner rotor 61 from an outer side in the radial direction and having the internal teeth 62a meshing with the external teeth 61a, the housing 10 includes the housing body portion 11 made of resin and the metal housing portion 25 made of metal, the housing body portion 11 includes the accommodation recess portion 17 that is recessed from the end portion on the lower side toward the upper side, that is, the other side (−Z side) in the axial direction and accommodates the pump 60, and the stator holding portion 12g that holds the stator 50, the accommodation recess portion 17 includes the recess portion inner circumferential surface 17a surrounding the pump 60 from the outer side in the radial direction, the metal housing portion 25 is at least partially embedded in the housing body portion 11, and the metal housing portion 25 includes the cylindrical circumferential wall portion 26 disposed between the pump 60 and the recess portion inner circumferential surface 17a in the radial direction. In the present example embodiment, since the housing body portion 11 is made of resin, the volume of the metal material forming the housing 10 can be reduced as compared with the case where the housing body portion 11 is made of metal. Further, since the housing body portion 11 is made of resin, the manufacturing cost of the housing 10 can be suitably reduced. Further, in the present example embodiment, the housing body portion 11 holds each of the stator 50 and the metal housing portion 25, and the metal housing portion 25 is at least partially embedded in the housing body portion 11. Therefore, in the present example embodiment, even when the temperature of the electric oil pump 1 varies, it is possible to more suitably suppress a decrease in the positional accuracy between the center axis of the stator 50 and the center axis of the metal housing portion 25. Accordingly, even when the temperature of the electric oil pump 1 varies, it is possible to suitably suppress a decrease in the positional accuracy between the center axis of the motor 40 and the center axis of the pump 60. Therefore, the loss of the driving force transmitted from the motor 40 to the pump 60 via the shaft 43 can be suitably reduced. Therefore, it is possible to suppress a decrease in the flow rate of the oil discharged from the pump 60 while reducing the weight of the electric oil pump 1.

[0105] In a case where the housing body portion 11 is made of resin, the thermal expansion of the housing body portion 11 in response to a temperature rise of the electric oil pump 1 is larger than that of the pump 60. Therefore, when the temperature of the electric oil pump 1 rises, the gap between the recess portion inner circumferential surface 17a and the pump 60 in the radial direction increases. In view of this, in the present example embodiment, as described above, the circumferential wall portion 26 made of metal is between the pump 60 and the recess portion inner circumferential surface 17a, so that the increase in gap can be suppressed between the pump 60 and the circumferential wall portion 26 in the radial direction even when the temperature of the electric oil pump 1 rises. Therefore, it is possible to suppress leakage of oil into a section between the pump 60 and the circumferential wall portion 26. Therefore, it is possible to suppress a decrease in the flow rate of the oil discharged from the pump 60 while reducing the weight of the electric oil pump 1.

[0106] In the present example embodiment, as described above, since the housing body portion 11 is made of resin, the size of the housing body portion 11 tends to vary greatly due to shrinkage after molding. Therefore, in order to avoid interference between the inner surface of the accommodation recess portion 17 and the pump 60, it is necessary to design the accommodation recess portion 17 and the pump 60 to achieve a large difference in size therebetween. Therefore, the gap in the radial direction between the pump 60 and the recess portion inner circumferential surface 17a tends to be large. Therefore, when the housing 10 does not include the metal housing portion 25, the amount of oil leaking into a section between the pump 60 and the recess portion inner circumferential surface 17a is likely to be large, and thus the flow rate of oil discharged from the pump 60 is likely to be low. In view of this, in the present example embodiment, as described above, the circumferential wall portion 26 made of metal is between the pump 60 and the recess portion inner circumferential surface 17a in the radial direction, so that leakage of oil into a section between the pump 60 and the circumferential wall portion 26 can be suppressed. Therefore, it is possible to suitably suppress a decrease in the flow rate of the oil discharged from the pump 60 while reducing the weight of the electric oil pump 1.

[0107] In the present example embodiment, as described above, the circumferential wall portion 26 made of metal is between the pump 60 and the recess portion inner circumferential surface 17a in the radial direction, and thus, a direct contact between the outer rotor 62 and the recess portion inner circumferential surface 17a made of resin can be suppressed. Therefore, while the electric oil pump 1 is operating, it is possible to suppress the wearing of the recess portion inner circumferential surface 17a due to friction with the outer rotor 62. Therefore, the durability of the electric oil pump 1 can be improved.

[0108] According to the present example embodiment, the accommodation recess portion 17 has the top surface 17e that is located more on the upper side, that is, the other side (−Z side) in the axial direction than the pump 60, and faces the pump 60 in the axial direction, and the metal housing portion 25 has the top wall portion 27 that is between the pump 60 and the top surface 17e in the axial direction. Therefore, it is possible to suppress the direct contact between each of the inner rotor 61 and the outer rotor 62 and the top surface 17e made of resin. Therefore, while the electric oil pump 1 is operating, wearing of the top surface 17e due to friction with the inner rotor 61 and the outer rotor 62 can be suppressed. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0109] According to the present example embodiment, the end portion of the circumferential wall portion 26 on the upper side, that is, the other side (−Z side) in the axial direction is connected to the end portion of the top wall portion 27 on the outer side in the radial direction over the entire circumference in the circumferential direction. Therefore, it is possible to suitably suppress the leakage of the oil to the outside of the metal housing portion 25 from between the circumferential wall portion 26 and the top wall portion 27. Therefore, it is possible to suppress the leakage of the oil into a section between the circumferential wall portion 26 and the recess portion inner circumferential surface 17a, and thus it is possible to more suitably suppress a decrease in the flow rate of the oil discharged from the pump 60.

[0110] According to the present example embodiment, the top wall portion 27 is provided with the first through hole 28 extending through the top wall portion 27 in the axial direction, and the surface of the top wall portion 27 facing the lower side, that is, the one side (+Z side) in the axial direction is located more on the lower side than the top surface 17e. Therefore, it is possible to suppress the direct contact between each of the inner rotor 61 and the outer rotor 62 and the top surface 17e made of resin, via the first through hole 28. Therefore, while the electric oil pump 1 is operating, wearing of the top surface 17e due to friction with the inner rotor 61 and the outer rotor 62 can be more suitably suppressed. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0111] According to the present example embodiment, the top wall portion 27 is provided with the first through hole 28 extending through the top wall portion 27 in the axial direction, the top surface 17e is provided with the first groove portion 19 that is recessed toward the upper side, that is, the other side (−Z side) in the axial direction and extends in a circumferential direction, and the first through hole 28 at least partially overlaps the first groove portion 19 as viewed in the axial direction. Accordingly, the inside of the first groove portion 19 is connected to the inside of the accommodation recess portion 17 through the first through hole 28 as described above. Therefore, while the electric oil pump 1 is operating, the oil that has flowed into the pump 60 through the suction port 32a partially flows in the circumferential direction inside the first groove portion 19 and is sucked into the gap G between the inner rotor 61 and the outer rotor 62. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be increased by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of the oil discharged from the pump 60 can be suitably increased.

[0112] According to the present example embodiment, the housing body portion 11 includes the motor accommodation portion 12 that accommodates the motor 40, the communication hole portion 18c through which the shaft 43 passes in the axial direction, the communication hole portion 18c connecting an inside of the motor accommodation portion 12 and an inside of the accommodation recess portion 17, the top wall portion 27 has an annular plate shape expanding in the radial direction, the metal housing portion 25 includes the tubular portion29 having a tubular shape and extending from an inner edge of the top wall portion 27 in the radial direction toward the upper side, that is, the other side (−Z side) in the axial direction, and the tubular portion 29 is between the shaft 43 and an inner circumferential surface of the communication hole portion 18c in the radial direction. Therefore, as described above, it is possible to suppress the direct contact between the shaft 43 and the communication hole portion 18c made of resin. Therefore, while the electric oil pump 1 is operating, wearing of the communication hole portion 18c due to friction with the shaft 43 can be suppressed. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0113] According to the present example embodiment, the housing 10 includes the pump cover 31 made of resin and closing the accommodation recess portion 17 from the lower side, that is, the one side (+Z side) in the axial direction, and the bottom plate portion 37 that is made of metal, that is fixed to the surface of the pump cover 31 facing upper side, that is, the other side (−Z side) in the axial direction, and that faces the pump 60 in the axial direction. Therefore, the volume of the metal material forming the housing 10 can be more suitably reduced as compared with the case where the pump cover 31 is made of metal. Therefore, the manufacturing cost of the housing 10 can be reduced more suitably, and the weight of the housing 10 can be reduced more suitably. Therefore, the manufacturing cost of the electric oil pump 1 can be reduced more suitably, and the weight of the electric oil pump 1 can be reduced more suitably.

[0114] In the present example embodiment, as described above, the bottom plate portion 37 can suppress direct contact between each of the inner rotor 61 and the outer rotor 62 and the pump cover 31 made of resin. Therefore, while the electric oil pump 1 is operating, it is possible to suppress the wearing of the pump cover 31 due to the friction with the inner rotor 61 and the outer rotor 62. Therefore, the durability of the electric oil pump 1 can be more suitably improved while reducing the weight of the electric oil pump 1.

[0115] According to the present example embodiment, the end portion of the bottom plate portion 37 on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion 26. Therefore, it is easy to suppress an increase in the gap between the bottom plate portion 37 and the circumferential wall portion 26, whereby suppression of direct contact between the pump 60 and the pump cover 31 made of resin via the gap between the bottom plate portion 37 and the circumferential wall portion 26 can be easily achieved. Therefore, while the electric oil pump 1 is operating, it is possible to more suitably suppress the wearing of the pump cover 31 due to the friction with the inner rotor 61 and the outer rotor 62. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0116] According to the present example embodiment, the end portion of the bottom plate portion 37 on the outer side in the radial direction comes into contact with the surface of the circumferential wall portion 26 facing the lower side, that is, the one side (+Z side) in the axial direction. The bottom plate portion 37 is more easily brought into contact with the circumferential wall portion 26 than in a case where the end portion of the bottom plate portion 37 on the outer side in the radial direction is located more on the inner side in the radial direction than the circumferential wall portion 26. In the present example embodiment, the end portion of the bottom plate portion 37 on the outer side in the radial direction comes into contact with the surface of the circumferential wall portion 26 facing the lower side, and thus the bottom plate portion 37 and the circumferential wall portion 26 can be in firm contact with each other. Since the bottom plate portion 37 and the circumferential wall portion 26 can be firmly in contact with each other, it is possible to suitably suppress leakage of the oil inside the metal housing portion 25 from between the bottom plate portion 37 and the circumferential wall portion 26. Therefore, it is possible to more suitably suppress a decrease in the flow rate of the oil discharged from the pump 60. Therefore, the volumetric efficiency of the pump 60 can be improved, and the pump efficiency can be improved.

[0117] According to the present example embodiment, a surface of the pump cover 31 facing the upper side, that is, the other side (−Z side) in the axial direction is provided with the second groove portion 33 that is recessed toward the lower side, that is, the one side (+Z side) in the axial direction and extends in the circumferential direction, the bottom plate portion 37 is provided with the second through hole 38 extending through the bottom plate portion 37 in the axial direction, and the second through hole 38 at least partially overlaps the second groove portion 33 as viewed in the axial direction. Accordingly, the inside of the second groove portion 33 is connected to the inside of the accommodation recess portion 17 through the second through hole 38 as described above. Therefore, while the electric oil pump 1 is operating, the oil that has flowed into the pump 60 through the suction port 32a partially flows in the circumferential direction inside the second groove portion 33 and is sucked into the gap G between the inner rotor 61 and the outer rotor 62, through the second through hole 38. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be more suitably increased by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of the oil discharged from the pump 60 can be more suitably increased.

[0118] According to the present example embodiment, as described above, the force toward the lower side received from the oil inside the first groove portion 19 and the force toward the upper side received from the oil inside the second groove portion 33 are applied to the pump 60, and thus, it is possible to suppress vibration of the inner rotor 61 and the outer rotor 62 while the electric oil pump 1 is operating. Therefore, the rotation of the inner rotor 61 and the outer rotor 62 can be stabilized, and thus, a decrease in the discharge amount of oil discharged from the pump 60 and variation in the discharge pressure of oil can be suitably suppressed.

[0119] FIG. 10 is a perspective view illustrating an electric oil pump 201 of the present example embodiment. In the following description, components similar to those of the first example embodiment described above are denoted by the same reference signs, and description thereof will be omitted. As illustrated in FIG. 11, the electric oil pump 201 of the present example embodiment is used, for example, for supplying oil to an attached body 5. The attached body 5 may be an automatic transmission, a drive device that drives an axle of a vehicle, or an electric flight vehicle such as an electric vertical takeoff and landing (EVTOL). The electric oil pump 201 includes a housing 210, the motor 40, a shaft 243, the control device 56, the pump 60, a first sealing member 91, and a second sealing member 92.

[0120] The housing 210 has a substantially cylindrical shape extending in the axial direction. The housing 210 accommodates each of the motor 40, the shaft 243, the control device 56, and the pump 60. The housing 210 includes a housing body portion 211, a lid portion 221, a metal housing portion 225, a pump cover 231, and a bottom plate portion 237. In the present example embodiment, the housing body portion 211, the lid portion 221, and the metal housing portion 225, the pump cover 231, and the bottom plate portion 237 are separate members.

[0121] The housing body portion 211 has a tubular shape extending in the axial direction. More specifically, the housing body portion 211 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The housing body portion 211 accommodates each of the motor 40, the shaft 243, and the pump 60. In the present example embodiment, the housing body portion 211 is made of resin. The housing body portion 211 may be made of another material such as a metal material. As a material forming the housing body portion 211, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, or the like can be used. In the present example embodiment, the housing body portion 211 is molded by insert molding using the metal housing portion 225 and a stator 50 of the motor 40 as inserts. The metal housing portion 225 is at least partially embedded in the housing body portion 211. Thus, the metal housing portion 225 is fixed to the housing body portion 211. The stator 50 is embedded in the housing body portion 211. The housing body portion 211 includes a motor accommodation portion 212, a pump accommodation portion 216, and a plurality of ribs 220.

[0122] The motor accommodation portion 212 is an upper side portion of the housing body portion 211. The motor accommodation portion 212 is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the pump accommodation portion 216. The motor accommodation portion 212 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The motor accommodation portion 212 is open on the upper side. The motor accommodation portion 212 accommodates the motor 40. In the present example embodiment, the outer diameter (outer shape) of the motor accommodation portion 212 is larger than the outer diameter (outer shape) of the pump accommodation portion 216. The outer diameter of the motor accommodation portion 212 may be smaller than the outer diameter of the pump accommodation portion 216. The motor accommodation portion 212 includes a first side wall portion 212a, a third welded portion 212d, the stator holding portion 12g, a step portion 212k, and the attachment portion 14. That is, the housing body portion 211 includes the stator holding portion 12g and the third welded portion 212d. The stator 50 is embedded in the stator holding portion 12g. Thus, the stator holding portion 12g holds the stator 50. The configurations and the like of the stator holding portion 12g and the attachment portion 14 of the present example embodiment are similar to the configurations and the like of the stator holding portion 12g and the attachment portion 14 of the first example embodiment described above.

[0123] The first side wall portion 212a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The first side wall portion 212a surrounds an upper side portion of each of the motor 40 and the shaft 243 from the outer side in the radial direction. The first side wall portion 212a is provided with the first annular groove portion 12c. The configuration and the like of the first annular groove portion 12c of the present example embodiment are similar to the configuration and the like of the first annular groove portion 12c of the first example embodiment described above. The first sealing member 91 is fitted in the first annular groove portion 12c. In the present example embodiment, the first sealing member 91 is an O-ring. The first sealing member 91 has an annular shape surrounding the housing body portion 211 from the outer side in the radial direction. The first sealing member 91 is attached to the housing body portion 211. As illustrated in FIG. 10, the first sealing member 91 is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the plurality of ribs 220.

[0124] As illustrated in FIG. 11, the third welded portion 212d has an annular shape protruding toward the upper side from the first side wall portion 212a. The third welded portion 212d has a substantially annular shape centered on the rotation axis J. The third welded portion 212d faces the lid portion 221 in the axial direction. The third welded portion 212d is provided with a first projection portion 212e. The first projection portion 212e is a projection protruding toward the upper side from the surface of the third welded portion 212d facing the upper side. The first projection portion 212e extends over the entire circumference in the circumferential direction.

[0125] The step portion 212k protrudes toward the lower side from the first side wall portion 212a and extends over the entire circumference in the circumferential direction. The step portion 212k has a substantially annular shape centered on the rotation axis J. The step portion 212k is connected to the pump accommodation portion 216 in the axial direction. The outer diameter of the step portion 212k is smaller than the outer diameter of the first side wall portion 212a.

[0126] The pump accommodation portion 216 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. As illustrated in FIG. 12, the surface of the pump accommodation portion 216 facing the lower side is a lower end portion of the housing body portion 211. The pump accommodation portion 216 has an opening portion 217c that opens on the lower side, that is, the one side (+Z side) in the axial direction. The pump accommodation portion 216 accommodates the pump 60. The pump accommodation portion 216 surrounds the pump 60 from the outer side in the radial direction. The pump accommodation portion 216 includes a second side wall portion 216a, a first welded portion 216b, and an annular wall portion 218. That is, the housing body portion 211 includes the first welded portion 216b. The pump accommodation portion 216 is provided with an accommodation recess portion 217. Thus, the housing body portion 211 includes the accommodation recess portion 217.

[0127] The second side wall portion 216a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The second side wall portion 216a surrounds a lower side portion of each of the pump 60 and the shaft 243 from the outer side in the radial direction. The second side wall portion 216a is connected to the step portion 212k in the axial direction. The outer diameter of the step portion 212k is larger than the outer diameter of the second side wall portion 216a.

[0128] The first welded portion 216b is disposed on the lower side of the second side wall portion 216a. The first welded portion 216b is connected to the second side wall portion 216a in the axial direction. The first welded portion 216b is a lower side end portion of the housing body portion 211. Therefore, the housing body portion 211 has the first welded portion 216b at the end portion in the axial direction. The first welded portion 216b protrudes more on the outer side in the radial direction than the second side wall portion 216a. As viewed in the axial direction, the first welded portion 216b has an annular shape centered on the rotation axis J. The first welded portion 216b faces the pump cover 231 in the axial direction. As illustrated in FIG. 15, the first welded portion 216b includes a first welded protrusion portion 216c. The first welded protrusion portion 216c is a projection that protrudes toward the lower side, that is, the one side (+Z side) in the axial direction from the surface of the first welded portion 216b facing the lower side. The first welded protrusion portion 216c extends over the entire circumference in the circumferential direction. As viewed in the axial direction, the first welded protrusion portion 216c has an annular shape centered on the rotation axis J. The size of the first welded protrusion portion 216c in the radial direction is larger than the size of the first welded protrusion portion 216c in the axial direction.

[0129] As illustrated in FIG. 12, the accommodation recess portion 217 is a hole that is recessed toward the upper side from the surface of the pump accommodation portion 216 facing the lower side. That is, the accommodation recess portion 217 is a hole that is recessed from the lower side of the housing body portion 211, that is, the end portion on the one side (+Z side) in the axial direction toward the upper side, that is, the other side (−Z side) in the axial direction. The accommodation recess portion 217 accommodates the pump 60. The accommodation recess portion 217 includes a recess portion inner circumferential surface 217a and a top surface 217e.

[0130] The recess portion inner circumferential surface 217a is a surface, of the inner surface of the accommodation recess portion 217, facing the inner side in the radial direction. As viewed in the axial direction, the recess portion inner circumferential surface 217a has a substantially circular shape centered on the rotation axis J. The recess portion inner circumferential surface 217a surrounds the pump 60 from the outer side in the radial direction. The opening portion 217c is the lower end of the recess portion inner circumferential surface 217a.

[0131] The top surface 217e is a surface, of the inner surface of the accommodation recess portion 217, facing the lower side. The top surface 217e is a surface, of the annular wall portion 218, facing the lower side. The top surface 217e faces the pump 60 in the axial direction. Other configurations and the like of the accommodation recess portion 217 of the present example embodiment are similar to other configurations and the like of the accommodation recess portion 17 of the first example embodiment described above.

[0132] The annular wall portion 218 has a substantially annular shape centered on the rotation axis J. The end portion of the annular wall portion 218 on the outer side in the radial direction is connected to the surface of the step portion 212k facing the inner side in the radial direction, over the entire circumference in the circumferential direction. The annular wall portion 218 is provided more on the lower side than the motor 40 and more on the upper side than the pump 60. The annular wall portion 218 is provided with an inner tubular portion 218a, a communication hole portion 218c, and an outflow hole 218e. Therefore, the housing body portion 211 includes the communication hole portion 218c.

[0133] The inner tubular portion 218a protrudes toward the upper side from the inner edge of the annular wall portion 218 in the radial direction. The inner tubular portion 218a has a substantially cylindrical shape that is centered on the rotation axis J. The inner circumferential surface of the inner tubular portion 218a is connected to the inner circumferential surface of the annular wall portion 218 in the axial direction.

[0134] The communication hole portion 218c is a hole extending through each of the annular wall portion 218 and the inner tubular portion 218a in the axial direction. The communication hole portion 218c is formed by the inner circumferential surface of the annular wall portion 218 and the inner circumferential surface of the inner tubular portion 218a. As viewed in the axial direction, the communication hole portion 218c has a substantially circular shape centered on the rotation axis J. The communication hole portion 218c connects the inside of the motor accommodation portion 212 and the inside of the accommodation recess portion 217. The shaft 243 passes through the inside of the communication hole portion 218c in the axial direction. The outflow hole 218e is a hole extending through the annular wall portion 218 in the axial direction. The outflow hole 218e is provided in a portion on the outer side of the annular wall portion 218 in the radial direction.

[0135] As illustrated in FIG. 10, the ribs 220 are provided on the outer circumferential surface of the second side wall portion 216a, that is, a surface facing the outer side of the pump accommodation portion 216 in the radial direction. That is, each rib 220 is provided on the surface of the housing body portion 211 facing the outer side in the radial direction. Therefore, the strength of the housing body portion 211 can be suitably increased by the ribs 220. Each rib 220 has a plate shape protruding toward the outer side in the radial direction from the pump accommodation portion 216. Although not elaborated in the figures, the ribs 220 include the first rib as in the first example embodiment described above. Although not elaborated in the figures, the first rib is fitted to the positioning portion 34a of the pump cover 231, as in the first example embodiment described above. The ribs 220 are spaced apart from each other in the circumferential direction as illustrated in FIG. 13. As illustrated in FIG. 10, each of the ribs 220 extends in the axial direction. As illustrated in FIG. 12, the upper side end portion of each rib 220 is connected to the surface of the first side wall portion 212a facing the lower side, and the lower side end portion of each of the ribs 220 is connected to the first welded portion 216b. That is, each of the ribs 220 connects the lower side of the motor accommodation portion 212 and the first welded portion 216b in the axial direction. Therefore, when the housing body portion 211 is molded, the ribs 220 can suppress warpage of the first welded portion 216b to have a portion more on the outer side in the radial direction located more on the upper side.

[0136] In the present example embodiment, the end portion of each rib 220 on the lower side is connected to the surface of the first welded portion 216b facing the outer side in the radial direction. Thus, in the present example embodiment, when the housing body portion 211 is molded, the ribs 220 can more suitably suppress the warpage, toward the upper side, of the end portion of the first welded portion 216b on the outer side in the radial direction. The lower side end portion of each rib 220 may not be connected to the surface of the first welded portion 216b facing the outer side in the radial direction. The upper side portion of each rib 220 is connected to the outer surface of the step portion 212k. That is, each rib 220 is connected to the step portion 212k.

[0137] As illustrated in FIG. 13, the plurality of ribs 220 include a plurality of first protruding ribs 220e and two second protruding ribs 220g. The number of the second protruding ribs 220g included in the plurality of ribs 220 may be one. As viewed in the axial direction, each of the first protruding ribs 220e protrudes from the second side wall portion 216a in a first direction D1 orthogonal to the axial direction. In the present example embodiment, the plurality of ribs 220 include six first protruding ribs 220e. The number of the first protruding ribs 220e included in the plurality of ribs 220 is not limited to that in the present example embodiment, and may be five or less, or seven or more. A second virtual straight line VL2 illustrated in FIG. 13 is a virtual straight line that extends in a second direction D2 intersecting both the axial direction and the first direction D1 and passes through the rotation axis J, that is, the center of the motor accommodation portion 212. In the present example embodiment, the second direction D2 is orthogonal to both the axial direction and the first direction D1. The second direction D2 may not be orthogonal to at least one of the axial direction and the first direction D1. As viewed in the axial direction, each of the second protruding ribs 220g protrudes from the second side wall portion 216a in the second direction D2. The second protruding ribs 220g face each other in the radial direction with the rotation axis J interposed therebetween. As viewed in the axial direction, each of the second protruding ribs 220g overlaps the second virtual straight line VL2. Therefore, according to the present example embodiment, when the housing body portion 211 is resin-molded, the housing body portion 211 having the plurality of ribs 220 can be molded by using only a pair of molds (slide molds) that move toward the opposite sides in the first direction D1, when a side surface intersecting the axial direction is molded as appropriate. Therefore, the number of molds used to mold the housing body portion 211 can be reduced as compared with a case where the ribs 220 radially protrude toward the outer side in the radial direction. Therefore, it is possible to suppress an increase in the manufacturing cost and the manufacturing steps for the housing body portion 211. Other configurations and the like of the housing body portion 211 of the present example embodiment are similar to other configurations and the like of the housing body portion 11 of the first example embodiment described above.

[0138] As illustrated in FIG. 11, the lid portion 221 has a substantially cylindrical shape that is centered on the rotation axis J and protrudes in the axial direction. The lid portion 221 is open on the lower side. The lid portion 221 is fixed to the upper end of the housing body portion 211. The lid portion 221 closes the upper side opening of the motor accommodation portion 212. The control device 56 is accommodated in the lid portion 221. In the present example embodiment, the lid portion 221 is made of resin. As a material forming the lid portion 221, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, or the like can be used. The lid portion 221 may be made of another material such as a metal material. The lid portion 221 includes the lid circumferential wall portion 22, a fourth welded portion 222a, and the board cover portion 23.

[0139] The fourth welded portion 222a has an annular shape protruding toward the outer side in the radial direction from the lower side end portion of the lid circumferential wall portion 22. As viewed in the axial direction, the fourth welded portion 222a has an annular shape centered on the rotation axis J. The fourth welded portion 222a faces the third welded portion 212d of the housing body portion 211 in the axial direction. The fourth welded portion 222a is provided with the second annular groove portion 22a. The second annular groove portion 22a is a groove that is recessed toward the upper side from the surface of the fourth welded portion 222a facing the lower side and extends over the entire circumference in the circumferential direction. The first projection portion 212e is inserted in the second annular groove portion 22a. Accordingly, the lid portion 221 can be accurately positioned with respect to the housing body portion 211 in the radial direction. In the present example embodiment, the surface of the second annular groove portion 22a facing the lower side and the first projection portion 212e are welded over the entire circumference in the circumferential direction. Thus, the third welded portion 212d and the fourth welded portion 222a are welded to each other. Therefore, in the present example embodiment, the section between the housing body portion 211 and the lid portion 221 can be suitably sealed, and thus the airtightness of the electric oil pump 201 can be suitably improved. Further, since it is not necessary to separately provide a sealing member such as an O-ring for sealing between the housing body portion 211 and the lid portion 221, it is possible to suppress an increase in the number of components of the electric oil pump 201.

[0140] As illustrated in FIG. 12, the pump cover 231 has a tubular shape extending in the axial direction. More specifically, the pump cover 231 has a substantially annular shape centered on the rotation axis J. The pump cover 231 is provided more on lower side in the axial direction than the pump 60. The pump cover 231 is fixed to a lower end of the pump accommodation portion 216. The pump cover 231 covers the pump 60 from the lower side. The pump cover 231 closes the accommodation recess portion 217 from the lower side, that is, from the one side (+Z side) in the axial direction. The pump cover 231 closes the opening portion 217c from the lower side. In the present example embodiment, the pump cover 231 is made of resin. As a material forming the pump cover 231, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, or the like can be used. The pump cover 231 may be made of another material such as a metal material. The pump cover 231 holds the bottom plate portion 237. The pump cover 231 includes a cover body portion 232, a second welded portion 236, and the protruding tubular portion 35. As illustrated in FIG. 14, the pump cover 231 includes cover protrusion portions 232g, 232h, and 232k.

[0141] The cover body portion 232 is an upper side portion of the pump cover 231 as illustrated in FIG. 12. The cover body portion 232 has a substantially annular shape centered on the rotation axis J. The cover body portion 232 is provided with the suction port 32a and the second groove portion 33. As illustrated in FIG. 14, the cover body portion 232 is provided with a protrusion portion 34. Although not elaborated in the figures, as described above, the first rib is fitted to the positioning portion 34a of the protrusion portion 34. As illustrated in FIG. 10, the cover body portion 232 is provided with a discharge port 232c and a plurality of cover ribs 235. Therefore, the pump cover 231 includes each of the discharge port 232c and the plurality of cover ribs 235. As illustrated in FIG. 15, the cover body portion 232 includes a first plate-shaped portion 236b. That is, the pump cover 231 includes the first plate-shaped portion 236b.

[0142] As illustrated in FIG. 10, the discharge port 232c is a hole extending through the cover body portion 232 in the radial direction. The discharge port 232c opens in the radial direction. As illustrated in FIG. 15, the discharge port 232c is connected to the second discharge-side groove portion 33c. The oil compressed in the pump 60 is discharged to the outside of the electric oil pump 201 through the discharge port 232c. As illustrated in FIG. 16, in the present example embodiment, the discharge port 232c is open in the second direction D2. The direction in which the discharge port 232c opens is not particularly limited, and may be the first direction D1 or may be a direction oriented between the second direction D2 and the first direction D1. As illustrated in FIG. 10, the discharge port 232c has a substantially rectangular shape as viewed in the radial direction.

[0143] As illustrated in FIG. 12, the second welded portion 236 has an annular shape protruding toward the outer side from the upper side end portion of the cover body portion 232 in the radial direction. As viewed in the axial direction, the second welded portion 236 has an annular shape surrounding the rotation axis J. The second welded portion 236 is an upper side end portion of the pump cover 231. Therefore, the pump cover 231 has the second welded portion 236 at the end portion in the axial direction. The second welded portion 236 faces the housing body portion 211 in the axial direction. More specifically, the second welded portion 236 faces the first welded portion 216b in the axial direction. As illustrated in FIG. 15, the second welded portion 236 includes a second welded protrusion portion 236a.

[0144] The second welded protrusion portion 236a is a projection protruding toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the second welded portion 236 facing the upper side. The second welded protrusion portion 236a extends over the entire circumference in the circumferential direction. As viewed in the axial direction, the second welded protrusion portion 236a has an annular shape centered on the rotation axis J. A size of the second welded protrusion portion 236a in the radial direction is larger than a size of the second welded protrusion portion 236a in the axial direction. The second welded protrusion portion 236a and the first welded protrusion portion 216c of the housing body portion 211 face each other in the axial direction. In the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a are welded over the entire circumference in the circumferential direction. Thus, the first welded portion 216b and the second welded portion 236 are welded to each other. That is, the pump accommodation portion 216 and the pump cover 231 are joined to each other by welding over the entire circumference in the circumferential direction. The pump cover 231 is fixed to the surface of the first welded portion 216b facing the lower side, that is, the one side (+Z side) in the axial direction. In the present example embodiment, a portion of the second welded portion 236 other than the second welded protrusion portion 236a faces the first welded portion 216b with a gap in the axial direction.

[0145] As illustrated in FIG. 12, the cover protrusion portions 232g, 232h, and 232k are projections that protrude toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the cover body portion 232 facing the upper side. The cover protrusion portions 232g and 232h face the first welded portion 216b in the axial direction with a gap in between. The cover protrusion portion 232k faces the pump 60 in the axial direction with a gap in between. As illustrated in FIG. 14, as viewed in the axial direction, the cover protrusion portion 232g is provided along the edge portions on both sides in the circumferential direction and the edge portion on the inner side in the radial direction of the second suction-side groove portion 33a. As viewed in the axial direction, the cover protrusion portion 232h is provided along edge portions on both sides in the circumferential direction and an edge portion on the inner side in the radial direction of the second discharge-side groove portion 33c. As viewed in the axial direction, the cover protrusion portion 232k has an annular shape surrounding the bottom plate portion 237.

[0146] As illustrated in FIG. 10, the cover ribs 235 are provided on the outer circumferential surface of the cover body portion 232, that is, the outer surface of the pump cover 231. Therefore, the strength of the pump cover 231 can be suitably increased by the cover ribs 235. Each of the cover ribs 235 has a plate shape protruding toward the outer side from the cover body portion 232 in the radial direction. The cover ribs 235 are spaced apart from each other in the circumferential direction as illustrated in FIG. 16. As illustrated in FIG. 10, each cover rib 235 extends in the axial direction. An upper side end portion of each cover rib 235 is connected to the surface of the second welded portion 236 facing the lower side. Therefore, when the pump cover 231 is molded, the cover ribs 235 can suppress the warpage of the second welded portion 236 to have a portion more on the outer side in the radial direction located more on the lower side.

[0147] As illustrated in FIG. 16, as viewed in the axial direction, each cover rib 235 protrudes in the second direction D2 from the cover body portion 232. As described above, in the present example embodiment, the discharge port 232c is open in the second direction D2. Therefore, each cover rib 235 protrudes from the outer surface of the pump cover 231 in a direction in which the discharge port 232c opens. Therefore, according to the present example embodiment, when the pump cover 231 is molded by injection molding, the pump cover 231 having the discharge port 232c and the plurality of cover ribs 235 can be molded by using only a pair of molds (slide molds) that move in the direction in which the discharge port 232c opens, that is, toward the opposite side in the second direction D2. Therefore, the number of molds used to mold the pump cover 231 can be reduced as compared with a case where the cover ribs 235 are configured to protrude toward the outer side in the radial direction. Therefore, it is possible to suppress an increase in the manufacturing cost and the manufacturing steps for the pump cover 231.

[0148] The plurality of cover ribs 235 include a first cover rib 235a and a second cover rib 235c. The first cover rib 235a and the second cover rib 235c are disposed adjacent to each other in the circumferential direction. The first cover rib 235a and the second cover rib 235c are disposed with the discharge port 232c interposed therebetween in the circumferential direction. The first cover rib 235a is provided more on one side (+θ side) in the circumferential direction than the second cover rib 235c. The first cover rib 235a is provided more on one side in the circumferential direction than the discharge port 232c. The first cover rib 235a is disposed in the vicinity of the discharge port 232c. The second cover rib 235c is provided more on the other side (−θ side) in the circumferential direction than the discharge port 232c. The second cover rib 235c is disposed in the vicinity of the discharge port 232c. Therefore, in the present example embodiment, the cover rib 235 is disposed on each of both sides of the discharge port 232c in the circumferential direction.

[0149] As illustrated in FIG. 15, the first plate-shaped portion 236b is disposed on the upper side, that is, the other side (−Z side) in the axial direction of the discharge port 232c. The first plate-shaped portion 236b has a plate shape spreading in a direction orthogonal to the axial direction. The first plate-shaped portion 236b protrudes toward the outer side in the radial direction from the discharge port 232c. As illustrated in FIGS. 10 and 15, in the present example embodiment, the first plate-shaped portion 236b is part of the second welded portion 236 in the circumferential direction. The first plate-shaped portion 236b is a portion of the second welded portion 236 that overlaps the discharge port 232c as viewed in the axial direction. The first plate-shaped portion 236b may be a member different from the second welded portion 236. As illustrated in FIG. 10, the first plate-shaped portion 236b is provided with a recessed portion 236c.

[0150] The recessed portion 236c is provided in the surface of the first plate-shaped portion 236b on the lower side, that is, the one side (+Z side) in the axial direction. The recessed portion 236c is a recess that is recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the first plate-shaped portion 236b facing the lower side. As illustrated in FIG. 15, the recessed portion 236c is connected to the surface of the discharge port 232c facing the lower side. That is, the recessed portion 236c is connected to the inner surface of the discharge port 232c. Accordingly, in the present example embodiment, the discharge port 232c can be provided on the upper side, and thus the length between the pump 60 and the discharge port 232c can be easily shortened.

[0151] The protruding tubular portion 35 includes the fourth annular groove portion 35a and a second plate-shaped portion 235f. Thus, the pump cover 231 includes the second plate-shaped portion 235f. As illustrated in FIG. 12, the fourth annular groove portion 35a is a groove that is recessed toward the inner side in the radial direction from the surface of the protruding tubular portion 35 facing the outer side in the radial direction and extends in the circumferential direction. The fourth annular groove portion 35a extends over the entire circumference in the circumferential direction. The second sealing member 92 is fitted in the fourth annular groove portion 35a. In the present example embodiment, the second sealing member 92 is an O-ring. The second sealing member 92 has an annular shape that surrounds the pump cover 231 from the outer side in the radial direction. The second sealing member 92 is attached to the pump cover 231. As illustrated in FIG. 10, the second sealing member 92 is provided more on the lower side, that is, the one side (+Z side) in the axial direction than the discharge port 232c. Therefore, in the present example embodiment, as illustrated in FIG. 12, each of the discharge port 232c and the plurality of ribs 220 can be disposed in a space surrounded by the housing body portion 211, the pump cover 231, the first sealing member 91, the second sealing member 92, and the attached body 5.

[0152] As illustrated in FIG. 15, the second plate-shaped portion 235f is disposed on the lower side, that is, the one side (+Z side) in the axial direction of the discharge port 232c. The second plate-shaped portion 235f has a plate shape spreading in a direction orthogonal to the axial direction. The second plate-shaped portion 235f protrudes toward the outer side in the radial direction from the discharge port 232c. As illustrated in FIGS. 10 and 15, in the present example embodiment, the second plate-shaped portion 235f is a part, in the circumferential direction, of the protruding tubular portion 35 more on the upper side than the fourth annular groove portion 35a. The second plate-shaped portion 235f is a portion of the protruding tubular portion 35 that is more on the upper side than the fourth annular groove portion 35a and overlaps the discharge port 232c as viewed in the axial direction. The other configurations and the like of the pump cover 231 of the present example embodiment are similar to the other configurations and the like of the pump cover 31 of the first example embodiment described above.

[0153] As illustrated in FIG. 12, the metal housing portion 225 is accommodated in the housing body portion 211. As described above, the metal housing portion 225 is at least partially embedded in the housing body portion 211. The metal housing portion 225 is made of metal. In the present example embodiment, the metal housing portion 225 is made of aluminum. In the present example embodiment, the metal housing portion 225 is formed by casting. As illustrated in FIG. 17, the metal housing portion 225 includes the circumferential wall portion 26, a top wall portion 227, and a tubular portion 229. As illustrated in FIG. 12, the metal housing portion 225 includes a support surface 225a and a recess portion 225c.

[0154] The circumferential wall portion 26 has a substantially cylindrical shape surrounding the rotation axis J. The circumferential wall portion 26 has a portion on the outer side in the radial direction embedded in the second side wall portion 216a. The circumferential wall portion 26 is fixed to the recess portion inner circumferential surface 217a. In the radial direction, the circumferential wall portion 26 is between the pump 60 and the recess portion inner circumferential surface 217a.

[0155] As illustrated in FIG. 17, the top wall portion 227 has a substantially annular plate shape expanding in the radial direction. The top wall portion 227 has a plate shape that expands toward the outer side in the radial direction from the end portion of the tubular portion 229 on the lower side, that is, the one side (+Z side) in the axial direction. The top wall portion 227 surrounds the rotation axis J. An upper side end portion of the circumferential wall portion 26 is connected to the end portion of the top wall portion 227 on the outer side in the radial direction over the entire circumference in the circumferential direction. As illustrated in FIG. 12, in the present example embodiment, the size of the top wall portion 227 in the axial direction is larger than the size of the circumferential wall portion 26 in the radial direction. An upper side portion of the top wall portion 227 is embedded in the annular wall portion 218. The top wall portion 227 is fixed to the top surface 217e. The top wall portion 227 is between the pump 60 and the top surface 217e in the axial direction. The shaft 243 passes through the inside of the top wall portion 227 in the axial direction. The shaft 243 is supported by the top wall portion 227 to be rotatable about the rotation axis J. As illustrated in FIG. 17, the top wall portion 227 is provided with a top wall through hole 227c and a top wall recess portion 227e. As illustrated in FIG. 12, the top wall portion 227 is provided with a first groove portion 228. As illustrated in FIG. 13, the top wall portion 227 is provided with a communication groove portion 227h.

[0156] The top wall through hole 227c illustrated in FIG. 17 is a hole extending through the top wall portion 227 in the axial direction. The top wall through hole 227c is provided in a portion on the outer side of the top wall portion 227 in the radial direction. As illustrated in FIG. 12, the top wall through hole 227c overlaps the outflow hole 218e as viewed in the axial direction.

[0157] As illustrated in FIG. 17, the top wall recess portion 227e is provided in the surface of the top wall portion 227 facing the outer side in the radial direction. The top wall recess portion 227e is a recess recessed toward the inner side in the radial direction from the surface of the top wall portion 227 facing the outer side in the radial direction. The top wall recess portion 227e is open on the upper side. The top wall recess portion 227e may not be open on the upper side. The top wall portion 227 is provided with a plurality of the top wall recess portions 227e. In the present example embodiment, the top wall portion 227 is provided with three top wall recess portions 227e. The number of top wall recess portions 227e provided in the top wall portion 227 may be two or less, or four or more. The top wall recess portions 227e are provided at a substantially equal interval along the circumferential direction. Although not elaborated in the figures, the housing body portion 211 is partially located inside each of the top wall recess portions 227e. Thus, rotation of the metal housing portion 225 relative to the housing body portion 211 in the circumferential direction can be suppressed.

[0158] As illustrated in FIG. 12, the first groove portion 228 is a groove recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the top wall portion 227 facing the lower side. The first groove portion 228 is open on the lower side. In the present example embodiment, the top wall portion 227 is provided with two first groove portions 228. The two first groove portions 228 include a first suction-side groove portion 228a and a first discharge-side groove portion 228c.

[0159] As illustrated in FIG. 13, each of the first suction-side groove portion 228a and the first discharge-side groove portion 228c is a substantially arc-shaped groove extending in the circumferential direction, as viewed in the axial direction. That is, the first groove portion 228 is a groove extending in the circumferential direction. The first suction-side groove portion 228a and the first discharge-side groove portion 228c are provided at different positions in the circumferential direction. The first suction-side groove portion 228a and the first discharge-side groove portion 228c face each other in the radial direction. More specifically, the first suction-side groove portion 228a and the first discharge-side groove portion 228c face each other in the radial direction, with the rotation axis J interposed therebetween.

[0160] As illustrated in FIG. 12, the inside of the second suction-side groove portion 33a is connected to the suction port 32a. The second suction-side groove portion 33a overlaps the first suction-side groove portion 228a as viewed in the axial direction. As illustrated in FIGS. 13 and 14, the second suction-side groove portion 33a and the first suction-side groove portion 228a have substantially the same shape as viewed in the axial direction. As illustrated in FIG. 13, the first suction-side groove portion 228a overlaps the top wall through hole 227c and the outflow hole 218e as viewed in the axial direction. The first suction-side groove portion 228a is connected to the inside of the motor accommodation portion 212 through the top wall through hole 227c and the outflow hole 218e.

[0161] As illustrated in FIG. 15, the second discharge-side groove portion 33c is connected to the discharge port 232c. As illustrated in FIG. 12, the second discharge side groove portion 33c overlaps the first discharge-side groove portion 228c as viewed in the axial direction. As illustrated in FIGS. 13 and 14, the second discharge-side groove portion 33c and the first discharge-side groove portion 228c have substantially the same shape as viewed in the axial direction.

[0162] As illustrated in FIG. 12, the communication groove portion 227h is a groove recessed toward the upper side from the surface of the top wall portion 227 facing the lower side. As illustrated in FIG. 13, the communication groove portion 227h extends linearly along the radial direction. The end portion of the communication groove portion 227h on the inner side in the radial direction is open to the inner circumferential surface of the top wall portion 227. The communication groove portion 227h has the end portion, on the outer side in the radial direction, open to the first discharge-side groove portion 228c. Accordingly, the communication groove portion 227h connects the inside of the top wall portion 227 and the first discharge-side groove portion 228c.

[0163] As illustrated in FIG. 17, the tubular portion 229 has a tubular shape extending toward the upper side, that is, the other side (−Z side) in the axial direction from the inner edge of the top wall portion 227 in the radial direction. The tubular portion 229 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The inner circumferential surface of the tubular portion 229 is connected to the inner circumferential surface of the top wall portion 227 in the axial direction. As illustrated in FIG. 12, the tubular portion 229 is disposed in the communication hole portion 218c. The shaft 243 passes through the inside of the tubular portion 229 in the axial direction. The tubular portion 229 is between the shaft 243 and the inner circumferential surface of the communication hole portion 218c in the radial direction.

[0164] The support surface 225a is formed by the inner circumferential surface of the top wall portion 227 and the inner circumferential surface of the tubular portion 229. As viewed in the axial direction, the support surface 225a has a circular shape centered on the rotation axis J. The shaft 243 is supported by the support surface 225a so as to be rotatable about the rotation axis J. As described above, the tubular portion 229 is between the shaft 243 and the inner circumferential surface of the communication hole portion 218c in the radial direction. Therefore, since a direct contact between the shaft 243 and the communication hole portion 218c made of resin can be suppressed, wearing of the communication hole portion 218c can be suppressed while the electric oil pump 201 is operating.

[0165] The recess portion 225c is a recess that is recessed toward the outer side in the radial direction from the support surface 225a. The recess portion 225c is provided over the entire circumference in the circumferential direction. The recess portion 225c is provided across the top wall portion 227 and the tubular portion 229 in the axial direction. The top wall portion 227 includes a first support portion 227g. The tubular portion 229 includes a second support portion 229c.

[0166] Each of the first support portion 227g and the second support portion 229c is part of the support surface 225a. The first support portion 227g is an intermediate portion of the inner circumferential surface of the top wall portion 227, between the end portion of the recess portion 225c and the end portion of the top wall portion 227 that are on the lower side in the axial direction. The second support portion 229c is an intermediate portion of the inner circumferential surface of the tubular portion 229 between the end portion of the recess portion 225c and the end portion of the tubular portion 229 that are on the upper side in the axial direction. Each of the first support portion 227g and the second support portion 229c supports the shaft 243. Other configurations and the like of the metal housing portion 225 of the present example embodiment are similar to other configurations and the like of the metal housing portion 25 of the first example embodiment described above.

[0167] The bottom plate portion 237 has a substantially disk shape expanding in the radial direction around the rotation axis J. The bottom plate portion 237 is fixed to the surface of the pump cover 231 on the upper side, that is, the other side (−Z side) in the axial direction. The bottom plate portion 237 is provided more on the lower side than the pump 60. The bottom plate portion 237 faces the pump 60 in the axial direction. In the present example embodiment, the bottom plate portion 237 is in contact with the circumferential wall portion 26 of the metal housing portion 225 in the axial direction. The bottom plate portion 237 may face the circumferential wall portion 26 with a gap in between in the axial direction. The end portion of the bottom plate portion 237 on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion 26. The bottom plate portion 237 is provided more on the inner side in the radial direction than the second welded portion 236. That is, the second welded portion 236 is located on the outer side in the radial direction of the bottom plate portion 237. In the present example embodiment, the bottom plate portion 237 is made of metal. As a material forming the bottom plate portion 237, aluminum, stainless steel, or the like can be used.

[0168] As illustrated in FIGS. 12 and 14, in the present example embodiment, the bottom plate portion 237 is fitted to the cover protrusion portions 232g, 232h, and 232k. Thus, the bottom plate portion 237 is fixed to the pump cover 231. The bottom plate portion 237 may be press-fitted or clearance fitted to the cover protrusion portions 232g, 232h, and 232k. The surface of the bottom plate portion 237 facing the upper side is located more on the upper side than the cover protrusion portions 232g, 232h, and 232k. Therefore, since direct contact between the pump 60 and the cover protrusion portions 232g, 232h, and 232k made of resin can be suppressed, it is possible to suppress the wearing of the cover protrusion portions 232g, 232h, and 232k while the electric oil pump 201 is operating. As illustrated in FIG. 14, the bottom plate portion 237 includes a hole portion 237c and the second through hole 38.

[0169] Configurations and the like of the second through hole 38 of the present example embodiment are similar to configurations and the like of the second through hole 38 of the first example embodiment described above. Specifically, the second through hole 38 is a hole extending through the bottom plate portion 237 in the axial direction. In the present example embodiment, the bottom plate portion 237 is provided with a pair of second through holes 38. The pair of second through holes 38 include a second suction-side through hole 38a and a second discharge-side through hole 38c. As viewed in the axial direction, the pair of second through holes 38 are line symmetrical with the line of symmetry being the rotation axis J, that is, a third virtual straight line VL3 passing through the center of the bottom plate portion 237. The second suction-side through hole 38a surrounds the second suction-side groove portion 33a as viewed in the axial direction. Therefore, as illustrated in FIG. 12, the inside of the second suction-side groove portion 33a is connected to the inside of the accommodation recess portion 217 through the second suction-side through hole 38a. As illustrated in FIG. 14, the second discharge-side through hole 38c surrounds the second discharge-side groove portion 33c as viewed in the axial direction. Therefore, as illustrated in FIG. 12, the inside of the second discharge-side groove portion 33c is connected to the inside of the accommodation recess portion 217 through the second discharge-side through hole 38c.

[0170] The hole portion 237c illustrated in FIG. 14 is a hole extending through the bottom plate portion 237 in the axial direction. The hole portion 237c is provided in a portion on the outer side of the bottom plate portion 237 in the radial direction. In the present example embodiment, the hole portion 237c is open on the outer side in the radial direction. The hole portion 237c may not be open on the outer side in the radial direction. As viewed in the axial direction, the hole portion 237c is provided at a position shifted from the third virtual straight line VL3. Therefore, the shape of the bottom plate portion 237 as viewed in the axial direction can be asymmetric with respect to the third virtual straight line VL3.

[0171] As illustrated in FIG. 11, the motor 40 is accommodated in the motor accommodation portion 212. In the axial direction, the motor 40 is provided more on the lower side in the axial direction than the control device 56 and more on the upper side in the axial direction than the pump 60. The motor 40 includes the rotor 41 and the stator 50 that faces the rotor 41 in the radial direction with a gap in between. As illustrated in FIG. 12, in the present example embodiment, the lower side portion of the insulator 52 is embedded in the step portion 212k. Thus, the strength of the step portion 212k can be improved. Configurations and the like of the motor 40 of the present example embodiment are similar to configurations and the like of the motor 40 of the first example embodiment described above.

[0172] As illustrated in FIG. 11, the shaft 243 has a substantially columnar shape that is centered on the rotation axis J and extends in the axial direction. The upper side portion of the shaft 243 passes through the inside of the rotor core 41a in the axial direction. The rotor core 41a is fixed to the outer circumferential surface of the shaft 243. Thus, the rotor 41 is fixed to the shaft 243. As illustrated in FIG. 12, a portion of the shaft 243 on the central side in the axial direction passes through the inside of the tubular portion 229 and the inside of the top wall portion 227 in the axial direction. As described above, the shaft 243 is supported by the support surface 225a so as to be rotatable about the rotation axis J. The lower side portion of the shaft 243 is coupled to the pump 60. Thus, the rotational torque of the rotor 41 is transmitted to the pump 60 through the shaft 243.

[0173] As illustrated in FIG. 11, the control device 56 includes a circuit board 57. The circuit board 57 is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the motor 40. The circuit board 57 supplies current to the motor 40. More specifically, the circuit board 57 supplies a current to the coil portion 53 of the stator 50. The circuit board 57 is accommodated in the lid portion 221. When the coil portion 53 is supplied with current, each of the rotor 41 and the shaft 243 rotates about the rotation axis J. Configurations and the like of the control device 56 of the present example embodiment are similar to configurations and the like of the control device 56 of the first example embodiment described above.

[0174] The pump 60 is accommodated in the pump accommodation portion 216. The pump 60 is accommodated in the metal housing portion 225. The pump 60 is coupled to the end portion of the shaft 243 on the lower side, that is, the one side (+Z side) in the axial direction. The pump 60 is driven by the power from the motor 40 to pump the oil. The pump 60 of the present example embodiment is a trochoid pump. That is, the electric oil pump 201 of the present example embodiment is a positive displacement electric oil pump. The pump 60 includes the inner rotor 61 and the outer rotor 62. Configurations and the like of the pump 60 of the present example embodiment are similar to configurations and the like of the pump 60 of the first example embodiment described above.

[0175] As illustrated in FIG. 12, the inside of the second suction-side groove portion 33a and the inside of the first suction-side groove portion 228a are connected in the axial direction via a gap G between the inner rotor 61 and the outer rotor 62, and the second suction-side through hole 38a. In the present example embodiment, the internal space of the second suction-side groove portion 33a, the gap G, and the first suction-side groove portion 228a connected to each other are referred to as a suction chamber A1. The suction chamber A1 is connected to the suction port 32a.

[0176] The inside of the second discharge-side groove portion 33c and the inside of the first discharge-side groove portion 228c are connected in the axial direction via the gap G between the inner rotor 61 and the outer rotor 62, and the second discharge-side through hole 38c. In the present example embodiment, the internal space of the second discharge-side groove portion 33c, the gap G, and the internal space of the first discharge-side groove portion 228c connected to each other, are referred to as a compression chamber A2. The compression chamber A2 is connected to the discharge port 232c.

[0177] When the pressure in the suction chamber A1 drops due to the rotation of the inner rotor 61 and the outer rotor 62 while the electric oil pump 201 is operating, the oil flows into the suction chamber A1 through the suction port 32a as indicated by the arrow F1 in FIG. 12. More specifically, although not elaborated in the figures, the oil flowing into the second suction-side groove portion 33a flows through the inside of the second suction-side groove portion 33a in the circumferential direction and is sucked into the gap G via the second suction-side through hole 38a. The oil sucked into the gap G partially flows into the first suction-side groove portion 228a. The oil that has flowed into the first suction-side groove portion 228a flows through the inside of the first suction-side groove portion 228a in the circumferential direction and is sucked into the gap G again.

[0178] When the gap G moves in the circumferential direction due to the rotation of the inner rotor 61 and the outer rotor 62, the oil moves from the suction chamber A1 to the compression chamber A2 as indicated by an arrow F2 in FIG. 12. Although not elaborated in the figures, the oil sucked into the gap G partially flows into the first discharge-side groove portion 228c. The oil that has flowed into the first discharge-side groove portion 228c flows through the first discharge-side groove portion 228c in the circumferential direction and is sucked into the gap G again. The oil sucked into the gap G flows into the second discharge-side groove portion 33c via the second discharge-side through hole 38c. The oil that has flowed into the second discharge-side groove portion 33c flows in the circumferential direction inside the second discharge-side groove portion 33c. Thus, when the pressure of the oil in the compression chamber A2 rises, as indicated by the arrow F3 in FIG. 12, the oil in the compression chamber A2 is pumped to the outside of the electric oil pump 201 through the discharge port 232c. Thus, the electric oil pump 201 supplies oil to the attached body 5.

[0179] As described above, the communication groove portion 227h connects the inside of the top wall portion 227 and the first discharge-side groove portion 228c. Therefore, as indicated by the arrow F4 in FIG. 12, the oil sucked into the gap G and the oil inside the first discharge-side groove portion 228c partially flow into the top wall portion 227 and flow toward the upper side between the shaft 243 and the support surface 225a. Therefore, oil can be supplied to a section between the shaft 243 and the support surface 225a. Accordingly, the shaft 243 and the support surface 225a can be suitably lubricated by the oil, and thus the frictional force between the shaft 243 and the support surface 225a can be reduced. As indicated by the arrow F4 in FIG. 12, the oil flowing toward the upper side between the shaft 243 and the support surface 225a flows into the motor accommodation portion 212. Therefore, the oil can be supplied to the inside of the motor accommodation portion 212. As described above, the pressure of the oil in the compression chamber A2 is high. Therefore, in the present example embodiment, the oil can flow into the top wall portion 227 from the first discharge-side groove portion 228c at a high flow rate. Therefore, the shaft 243 and the support surface 225a can be suitably lubricated by the oil, and the amount of oil flowing into the motor accommodation portion 212 can be increased.

[0180] The rotation of the rotor 41 causes the oil flowed into the motor accommodation portion 212 to circulate inside the motor accommodation portion 212, and cool each of the motor 40 and the control device 56. As described above, the first suction-side groove portion 228a is connected to the inside of the motor accommodation portion 212 through the top wall through hole 227c and the outflow hole 218e. Therefore, when the pressure in the suction chamber A1 drops while the electric oil pump 201 is operating, the oil circulating inside the motor accommodation portion 212 partially flows into the first suction-side groove portion 228a through the top wall through hole 227c and the outflow hole 218e as indicated by the arrow F5 in FIG. 12. The oil that has flowed into the first suction-side groove portion 228a is pumped to the outside of the electric oil pump 201 through the discharge port 232c, together with the oil that has flowed into the suction chamber A1 through the suction port 32a.

[0181] According to the present example embodiment, the size of the top wall portion 227 in the axial direction is larger than the size of the circumferential wall portion 26 in the radial direction. Therefore, the rigidity of the top wall portion 227 in the axial direction can be increased as compared with a case where the size of the top wall portion 227 in the axial direction is equal to or less than the size of the circumferential wall portion 26 in the radial direction. Accordingly, the shaft 243 can be stably supported by the first support portion 227g, and thus the rotation of the shaft 243 about the rotation axis J can be stabilized. Therefore, the loss of the driving force transmitted from the motor 40 to the pump 60 can be more suitably reduced. Thus, the reduction in flow rate of oil discharged from the pump 60 can be suppressed. Therefore, the discharge performance of the electric oil pump 201 can be more suitably improved while reducing the weight of the electric oil pump 201.

[0182] According to the present example embodiment, the top wall portion 227 is provided with the first groove portion 228 that is recessed toward the upper side, that is, the other side (−Z side) in the axial direction and extends in the circumferential direction. Therefore, as described above, while the electric oil pump 201 is operating, the oil that has flowed into the pump 60 through the suction port 32a partially flows through the inside of the first groove portion 228 in the circumferential direction and is sucked into the gap G between the inner rotor 61 and the outer rotor 62. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be increased by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of the oil discharged from the pump 60 can be suitably increased.

[0183] According to the present example embodiment, the surface of the top wall portion 227 facing the outer side in the radial direction is provided with the top wall recess portion 227e recessed toward the inner side in the radial direction, and the housing body portion 211 is partially located in the top wall recess portion 227e. Therefore, when the metal housing portion 225 attempts to rotate about the rotational axis J due to the friction force between the shaft 243 and the metal housing portion 225 while the electric oil pump 201 is operating, part of the housing body portion 211 is caught on the inner side surface of the top wall recess portion 227e. Therefore, while the electric oil pump 201 is operating, rotation of the metal housing portion 225 about the rotation axis J can be suppressed.

[0184] According to the present example embodiment, the top wall portion 227 includes the first support portion 227g supporting the shaft 243, the tubular portion 229 includes the second support portion 229c supporting the shaft 243. In the present example embodiment, as described above, the size of the top wall portion 227 in the axial direction is larger than the size of the circumferential wall portion 26 in the radial direction, and thus the size of the top wall portion 227 in the axial direction is easily increased. This makes it easy to increase the axial direction distance between the first support portion 227g and the second support portion 229c relative to the axial direction distance between the first support portion 227g and the portion of the shaft 243 coupled to the inner rotor 61. Therefore, even when the load applied from the pump 60 to the shaft 243 is large, the load applied to each of the first support portion 227g and the second support portion 229c can be suppressed. Therefore, since it is possible to suppress an increase in the friction force between the shaft 243 and each of the first support portion 227g and the second support portion 229c, it is possible to suppress wearing of at least one of the shaft 243, the first support portion 227g, and the second support portion 229c. Therefore, the durability of the electric oil pump 201 can be improved.

[0185] According to the present example embodiment, the pump cover 231 includes the cover protrusion portions 232g, 232h, and 232k that protrude toward the upper side, that is, the other side (−Z side) in the axial direction, and the bottom plate portion 237 is fitted to the cover protrusion portions 232g, 232h, and 232k. As described above, in the present example embodiment, the pump cover 231 is made of resin, and the bottom plate portion 237 is made of metal, and thus, the difference in linear expansion coefficient between the pump cover 231 and the bottom plate portion 237 is large. Therefore, when the pump cover 231 is molded by insert molding using the bottom plate portion 237 as an insert, a difference in the amount of thermal contraction between the pump cover 231 after molding and the bottom plate portion 237 is large, and thus the warpage in the axial direction of the second welded portion 236 located on the outer side in the radial direction of the bottom plate portion 237 is likely to be large. In contrast, in the present example embodiment, after the pump cover 231 is molded, the bottom plate portion 237 is fitted to the cover protrusion portions 232g, 232h, and 232k, so that the bottom plate portion 237 can be fixed to the pump cover 231. Therefore, in the present example embodiment, the warpage of the second welded portion 236 in the axial direction can be suppressed. Therefore, it is possible to suppress a decrease in flatness of the surface of the second welded portion 236 facing the upper side. Accordingly, the second welded portion 236 and the first welded portion 216b can be stably welded over the entire circumference in the circumferential direction, and thus it is possible to suitably suppress the production of a gap between the second welded portion 236 and the first welded portion 216b. Therefore, the airtightness between the housing body portion 211 and the pump cover 231 can be suitably improved, and thus leakage of the oil from between the housing body portion 211 and the pump cover 231 can be suitably suppressed.

[0186] According to the present example embodiment, the bottom plate portion 237 is provided with the pair of second through holes 38 extending through the bottom plate portion 237 in the axial direction, as viewed in the axial direction, the pair of second through holes 38 have shapes that are line-symmetrical to each other with respect to the third virtual straight line VL3 as a virtual straight line passing through a center of the bottom plate portion 237 as a line of symmetry, and the bottom plate portion 237 includes the hole portion 237c extending through the bottom plate portion 237 in the axial direction at a position shifted from the third virtual straight line VL3. Therefore, as described above, the shape of the bottom plate portion 237 as viewed in the axial direction can be asymmetric with respect to the third virtual straight line VL3. Therefore, in the assembly process for the electric oil pump 201, the bottom plate portion 237 is attached to the pump cover 231 while the position of the hole portion 237c with respect to the pump cover 231 is checked, so that it is possible to suppress attachment of the bottom plate portion 237 to the pump cover 231 in a state where the surface of the bottom plate portion 237 facing the axial direction is reversed. Therefore, the bottom plate portion 237 is easily attached to the pump cover 231 appropriately, and thus the operation of attaching the bottom plate portion 237 to the pump cover 231 can be simplified. Therefore, it is possible to suppress an increase in the number of assembly steps for the electric oil pump 201.

[0187] In addition to the hole portion 237c, the bottom plate portion 237 may have a notch extending in the circumferential direction at the end portion of one of the pair of second through holes 38 in the circumferential direction. Also in this case, the shape of the bottom plate portion 237 as viewed in the axial direction can be asymmetric with respect to the third virtual straight line VL3. Therefore, it is possible to suppress the attachment of the bottom plate portion 237 to the pump cover 231 in a state where the surface of the bottom plate portion 237 facing the axial direction is reversed.

[0188] According to the present example embodiment, the electric oil pump 201 is a positive displacement electric oil pump, the housing 210 includes the pump cover 231 that is made of resin and closes the accommodation recess portion 217 from the lower side, that is, the one side (+Z side) in the axial direction, the housing body portion 211 includes the first welded portion 216b facing the pump cover 231, the first welded portion 216b includes the first welded protrusion portion 216c protruding toward the lower side, the pump cover 231 includes the second welded portion 236 facing the housing body portion 211, the second welded portion 236 includes the second welded protrusion portion 236a protruding toward the upper side, that is, the other side (−Z side) in the axial direction, and the first welded protrusion portion 216c and the second welded protrusion portion 236a are welded to each other. In a case where the first welded portion 216b and the second welded portion 236 do not have the first welded protrusion portion 216c and the second welded protrusion portion 236a, respectively, the surface of the first welded portion 216b facing the lower side, the surface of the second welded portion 236 facing the upper side, and the surface of the pump 60 facing the lower side are located on the same plane, and thus it is difficult to weld the first welded portion 216b and the second welded portion 236 in a state where the pump cover 231 and the pump 60 are in contact with each other in the axial direction. Therefore, it is difficult to increase the joint strength between the first welded portion 216b and the second welded portion 236. A known non-positive displacement pump may employ a configuration in which the pump cover 231 is fixed to the housing body portion 211 by welding. However, with the positive displacement pump, since a fluid such as oil having a high viscosity is discharged, a discharge pressure is higher than that in a case where a fluid having a low viscosity such as water is used. Thus, it is difficult to adopt a configuration in which the pump cover 231 is fixed to the housing body portion 211 by welding. Therefore, in the known positive displacement pump, the pump cover 231 is fixed to the housing body portion 211 using a fixing member such as a bolt. That is, while there has been a demand for a smaller size, a lighter weight, and a lower cost regarding a positive displacement pump, it has been a long unsolved problem to employ a configuration in which the pump cover 231 is fixed to the housing body portion 211 by welding without using a fixing member such as a bolt. In view of this, in the present example embodiment, the first welded protrusion portion 216c can be disposed more on the lower side than the surface of the pump 60 facing the lower side, and the second welded protrusion portion 236a can be disposed more on the upper side than the surface of the pump cover 231 facing the upper side, and thus the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded to each other in a state of being reliably in contact with each other in the axial direction. Therefore, in the present example embodiment, the pump cover 231 can be firmly fixed to the housing body portion 211 by welding. Therefore, the number of components of the electric oil pump 201 can be reduced as compared with a case where the housing body portion 211 and the pump cover 231 are fixed to each other using bolts or the like. Further, since the number of components of the electric oil pump 201 can be reduced, the weight of the electric oil pump 201 can be reduced, and the manufacturing cost can be reduced.

[0189] According to the present example embodiment, a size of the first welded protrusion portion 216c in the radial direction is larger than a size of the first welded protrusion portion 216c in the axial direction, and a size of the second welded protrusion portion 236a in the radial direction is larger than a size of the second welded protrusion portion 236a in the axial direction. Therefore, when the first welded portion 216b and the second welded portion 236 are welded, even if the position of the center axis of the pump cover 231 with respect to the center axis of the housing body portion 211 is shifted in the radial direction, the first welded protrusion portion 216c and the second welded protrusion portion 236a are easily brought into contact with each other in the axial direction. Accordingly, in the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a are easily welded to each other in a reliable manner, and thus it is possible to more suitably improve the airtightness between the first welded portion 216b and the second welded portion 236. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0190] According to the present example embodiment, the first welded protrusion portion 216c can be disposed more on the lower side than the surface of the pump 60 facing the lower side, and the second welded protrusion portion 236a can be disposed more on the upper side than the surface of the pump cover 231 facing the upper side, and thus the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded to each other in a state of being reliably in contact with each other in the axial direction. Therefore, in the present example embodiment, the pump cover 231 can be firmly fixed to the housing body portion 211. According to the present example embodiment, a size of the first welded protrusion portion 216c in the radial direction is larger than a size of the first welded protrusion portion 216c in the axial direction, and a size of the second welded protrusion portion 236a in the radial direction is larger than a size of the second welded protrusion portion 236a in the axial direction as described above. Therefore, the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded over a large area, and thus the airtightness between the first welded portion 216b and the second welded portion 236 can be more suitably improved. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231. Further, with this configuration, the airtightness between the housing body portion 211 and the pump cover 231 can be suitably improved by welding the first welded portion 216b and the second welded portion 236 without using a sealing member such as an O-ring, and thus it is possible to suitably suppress leakage of oil from between the housing body portion 211 and the pump cover 231.

[0191] In the present example embodiment, a portion of the second welded portion 236 other than the second welded protrusion portion 236a faces the first welded portion 216b with a gap in the axial direction. When the portion of the second welded portion 236 other than the second welded protrusion portion 236a comes into contact with the first welded portion 216b in the axial direction, the first welded protrusion portion 216c and the second welded protrusion portion 236a are less likely to come into contact with each other in the axial direction, and thus it is difficult to reliably weld the first welded protrusion portion 216c and the second welded protrusion portion 236a. In contrast, in the present example embodiment, the portion of the second welded portion 236 other than the second welded protrusion portion 236a faces the first welded portion 216b in the axial direction with a gap in between, and thus the first welded protrusion portion 216c and the second welded protrusion portion 236a can be more suitably brought into contact with each other in the axial direction. Accordingly, in the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded to each other in a more reliable manner, and thus it is possible to more suitably improve the airtightness between the first welded portion 216b and the second welded portion 236. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0192] According to the present example embodiment, the second welded portion 236 is located on the outer side in the radial direction of the bottom plate portion 237. Therefore, compared with a configuration in which the second welded portion 236 is located more on the inner side in the radial direction than the edge portion of the bottom plate portion 237 on the outer side in the radial direction, the structure of each of the second welded portion 236 and the first welded portion 216b of the housing body portion 211 can be simplified. In addition, since the second welded portion 236 is located on the outer side in the radial direction of the bottom plate portion 237, it is possible to improve the workability of the work of welding the first welded portion 216b and the second welded portion 236.

[0193] According to the present example embodiment, as illustrated in FIG. 15, the second welded portion 236 (the second welded protrusion portion 236a) overlaps the bottom plate portion 237 in the radial direction. In the present example embodiment, the second welded portion 236 (the second welded protrusion portion 236a) is disposed at a position overlapping the bottom plate portion 237 in the radial direction, and thus it is possible to achieve uniformity of the thickness of the portion of the pump cover 231 from the first plate-shaped portion 236b to the second welded portion 236 (the second welded protrusion portion 236a). Therefore, it is possible to suppress the occurrence of sink in the vicinity of the first plate-shaped portion 236b and the second welded portion 236 (the second welded protrusion portion 236a). Therefore, it is possible to more suitably suppress a decrease in flatness of the surface of the second welded portion 236 facing the upper side. Accordingly, the second welded portion 236 and the first welded portion 216b can be more stably welded over the entire circumference in the circumferential direction, and thus it is possible to more suitably suppress the production of a gap between the second welded portion 236 and the first welded portion 216b. Therefore, the airtightness between the housing body portion 211 and the pump cover 231 can be more suitably improved, and thus leakage of the oil from between the housing body portion 211 and the pump cover 231 can be more suitably suppressed.

[0194] According to the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a overlap the bottom plate portion 237 in the radial direction. Therefore, in the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a are welded to each other in the vicinity of the position where the bottom plate portion 237 and the circumferential wall portion 26 are in contact with each other. Accordingly, the first welded protrusion portion 216c and the second welded protrusion portion 236a located in the vicinity of the position where the bottom plate portion 237 and the circumferential wall portion 26 are in contact with each other can block the oil leakage from the inside of the metal housing portion 25. Therefore, the amount of oil leaking from the inside of the metal housing portion 25 can be reduced. Therefore, it is possible to suitably suppress a decrease in the flow rate of the oil discharged from the pump 60. Therefore, the volumetric efficiency of the pump 60 can be increased, and a decrease in the pump efficiency can be suppressed.

[0195] According to the present example embodiment, the bottom plate portion 237 comes into contact with the circumferential wall portion 26 in the axial direction. Therefore, it is easy to suppress the direct contact between the pump 60 and the pump cover 231 made of resin via the gap between the bottom plate portion 237 and the circumferential wall portion 26. Therefore, while the electric oil pump 201 is operating, it is possible to more suitably suppress the wearing of the pump cover 231 due to the friction with the inner rotor 61 and the outer rotor 62. Therefore, the durability of the electric oil pump 201 can be more suitably improved.

[0196] According to the present example embodiment, the housing body portion 211 includes the pump accommodation portion 216 that surrounds the pump 60 from the outer side in the radial direction, and the motor accommodation portion 212 that accommodates the motor 40 and is provided more on the upper side, that is the other side (−Z side) in the axial direction than the pump accommodation portion 216, the plurality of ribs 220 are provided on the surface of the pump accommodation portion 216 facing the outer side in the radial direction, and the plurality of ribs 220 are spaced apart from each other along the circumferential direction, and connect in the axial direction, the surface of the motor accommodation portion 212 facing the lower side, that is, the one side (+Z side) in the axial direction and the first welded portion 216b. Therefore, as described above, in the present example embodiment, when the housing body portion 211 is molded, the plurality of ribs 220 can suppress warpage of the first welded portion 216b to have a portion more on the outer side in the radial direction located more on the upper side. Therefore, it is possible to suppress a decrease in flatness of the surface of the first welded portion 216b facing the lower side. Accordingly, the first welded portion 216b and the second welded portion 236 can be more reliably welded, and thus the airtightness between the housing body portion 211 and the pump cover 231 can be more suitably improved. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0197] In the present example embodiment, as described above, the pump cover 231 includes the plurality of cover ribs 235 protruding from the outer surface of the pump cover 231, and the end portion of each cover rib 235 on the upper side is connected to the surface of the second welded portion 236 facing the lower side. Therefore, when the pump cover 231 is molded, the cover ribs 235 can suppress the warpage of the second welded portion 236 to have a portion more on the outer side in the radial direction located more on the lower side as described above. Therefore, it is possible to suppress a decrease in flatness of the surface of the second welded portion 236 facing the upper side. Accordingly, the first welded portion 216b and the second welded portion 236 can be more reliably welded, and thus the airtightness between the housing body portion 211 and the pump cover 231 can be more suitably improved. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0198] According to the present example embodiment, the electric oil pump 201 further includes the circuit board 57 that is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the motor 40 and supplies current to the motor 40, the housing 210 includes the lid portion 221 made of resin that accommodates the circuit board 57, the housing body portion 211 includes the third welded portion 212d facing the lid portion 221, the lid portion 221 includes the fourth welded portion 222a facing the third welded portion 212d, and the third welded portion 212d and the fourth welded portion 222a are welded to each other. Therefore, since the housing body portion 211 and the lid portion 221 can be fixed by welding, the number of components of the electric oil pump 201 can be reduced as compared with a case where the housing body portion 211 and the lid portion 221 are fixed using bolts or the like.

[0199] While the example embodiments of the present disclosure have been described above, the configurations in the example embodiments, combinations thereof, and the like are an example, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present disclosure. Note that the present disclosure is not limited to the example embodiments described above.

[0200] The pump cover may be made of metal. In this case as well, the housing body portion is made of resin, and thus the weight of the housing can be reduced. Therefore, the weight of the electric oil pump can be reduced. In this case, the housing may not have the bottom plate portion.

[0201] The metal housing portion may not have the tubular portion. In this case, the shaft and the inner circumferential surface of the communication hole portion can be lubricated using oil, and thus wearing of the inner circumferential surface of the communication hole portion can be suppressed.

[0202] The metal housing portion may be fixed to the housing body portion using an adhesive or the like. Also in this case, each of the circumferential wall portion, the top wall portion, and the tubular portion can suppress wearing of the housing body portion. The bottom plate portion may be fixed to the pump cover using an adhesive or the like. Also in this case, the bottom plate portion can suppress the wearing of the pump cover.

[0203] The pump cover may include the pump accommodation portion. With this configuration, the metal housing portion is accommodated in the pump accommodation portion of the pump cover, the bottom plate portion is fixed to the housing body portion, and the housing body portion is provided with the first groove portion. With this configuration, the bottom plate portion may have a tubular portion extending toward the other side in the axial direction, and a rib may be provided at a corner portion between the bottom plate portion and the tubular portion to improve the strength for supporting the shaft.

[0204] The lid portion may include a metal plate for preventing an influence of electromagnetic noise. In this case, the lid portion may have a protrusion portion to which the metal plate is fitted, such that the pump cover has a cover protrusion portion to which the bottom plate portion is fitted. That is, the lid portion may have a protrusion portion for fixing the metal plate. The metal plate may be fixed to the lid portion by thermal caulking. The protrusion portion of the lid portion may be provided at a portion of the lid portion on the inner side in the radial direction or may have a stepped shape to prevent the flatness of the fourth welded portion from being compromised.

[0205] While in the above-described example embodiment, the circuit board is provided more on the other side in the axial direction than the motor, the circuit board may be disposed at another position. The circuit board may be disposed along the axial direction. In the case where the circuit board is disposed along the axial direction, the housing body portion or the lid portion can have a board accommodation portion that is open in the radial direction and accommodates the circuit board. The board accommodation portion of the housing body portion or the board accommodation portion of the lid portion can appropriately accommodate the circuit board, a member electrically connecting the stator and the circuit board, and the like and can have a minimum possible size in the radial direction by appropriately configuring the wall portion having the height in the radial direction. Further, since the circuit board is not disposed more on the other side in the axial direction than the motor, the size in the axial direction can be made small. The wall portion having the height in the radial direction may be included in both the housing body portion and the lid portion, or may be included in only one of the housing body portion and the lid portion. When the circuit board is disposed along the axial direction, the third welded portion of the housing body portion and the fourth welded portion of the lid portion can be welded in the radial direction by configuring the first projection portion and the second annular groove portion to be oriented in the radial direction. The first projection portion and the second annular groove portion are formed in a rectangular frame shape having a long side in the axial direction and a short side in the radial direction, so that the section between the housing body portion and the lid portion can be sealed without using a sealing member such as an O-ring while the size of the board accommodation portion is set to a minimum necessary size along the shape of the circuit board.

[0206] The housing body portion or the lid portion may include a columnar boss made of resin from an inner side surface serving as the board accommodation portion. The boss of the housing body portion or the lid portion may be inserted in a hole formed in the circuit board, and the circuit board may be fixed by thermal caulking.

[0207] The use of the electric oil pump to which the present disclosure is applied is not particularly limited. The type of fluid fed by the electric oil pump is not particularly limited, and may be a liquid other than oil, such as water. The electric oil pump may be installed in an attached body other than the vehicle. The configurations described above in the present specification can be combined as appropriate within a range in which they do not contradict each other.

[0208] Note that the present technology can have configurations such as the following.

[0209] (1) An electric oil pump including a shaft extending in an axial direction, a motor including a rotor that is rotatably fixed to the shaft and a stator facing the rotor with a gap in a radial direction, a pump driven to pump oil by power of the motor, and a housing accommodating the motor and the pump, wherein the pump includes an inner rotor coupled to the shaft on one side in the axial direction and including external teeth, and an outer rotor surrounding the inner rotor from an outer side in the radial direction and including internal teeth meshing with the external teeth, the housing includes a housing body portion made of resin and a metal housing portion made of metal, the housing body portion includes an accommodation recess portion that is recessed from an end portion on one side in the axial direction toward another side in the axial direction and accommodates the pump, and a stator holding portion that holds the stator, the accommodation recess portion includes a recess portion inner circumferential surface surrounding the pump from the outer side in the radial direction, the metal housing portion is at least partially embedded in the housing body portion, and the metal housing portion includes a cylindrical circumferential wall portion between the pump and the recess portion inner circumferential surface in the radial direction.

[0210] (2) The electric oil pump according to (1), wherein the accommodation recess portion includes a top surface that is located more on the other side in the axial direction than the pump and faces the pump in the axial direction, and the metal housing portion includes a top wall portion between the pump and the top surface in the axial direction.

[0211] (3) The electric oil pump according to (2), wherein an end portion of the circumferential wall portion on the other side in the axial direction is connected to an end portion of the top wall portion on the outer side in the radial direction over entire circumference in a circumferential direction.

[0212] (4) The electric oil pump according to (2) or (3), wherein the top wall portion is provided with a first through hole extending through the top wall portion in the axial direction, and a surface of the top wall portion facing the one side in the axial direction is located more on the one side in the axial direction than the top surface.

[0213] (5) The electric oil pump according to any one of (2) to (4), wherein the top wall portion is provided with a first through hole extending through the top wall portion in the axial direction, the top surface is provided with a first groove portion that is recessed toward the other side in the axial direction and extends in a circumferential direction, and the first through hole at least partially overlaps the first groove portion as viewed in the axial direction.

[0214] (6) The electric oil pump according to (2) or (3), wherein a size of the top wall portion in the axial direction is larger than a size of the circumferential wall portion in the radial direction.

[0215] (7) The electric oil pump according to (6), wherein the top wall portion is provided with a first groove portion that is recessed toward the other side in the axial direction and extends in a circumferential direction.

[0216] (8) The electric oil pump according to (6) or (7), wherein a surface of the top wall portion facing the outer side in the radial direction is provided with a top wall recess portion recessed toward an inner side in the radial direction, and the housing body portion is partially located inside the top wall recess portion.

[0217] (9) The electric oil pump according to any one of (2) to (8), wherein the housing body portion includes a motor accommodation portion that accommodates the motor, a communication hole portion through which the shaft passes in the axial direction, the communication hole portion connecting an inside of the motor accommodation portion and an inside of the accommodation recess portion, the top wall portion has an annular plate shape expanding in the radial direction, the metal housing portion includes a tubular portion having a tubular shape and extending from an inner edge of the top wall portion in the radial direction toward the other side in the axial direction, and the tubular portion is between the shaft and an inner circumferential surface of the communication hole portion in the radial direction.

[0218] (10) The electric oil pump according to (9), wherein the top wall portion includes a first support portion that supports the shaft, and the tubular portion includes a second support portion that supports the shaft.

[0219] (11) The electric oil pump according to any one of (1) to (10), wherein the housing body portion is molded by insert molding using the metal housing portion as an insert.

[0220] (12) The electric oil pump according to any one of (1) to (11), wherein the housing includes a pump cover made of resin and closing the accommodation recess portion from the one side in the axial direction, and a bottom plate portion that is made of metal, that is fixed to a surface of the pump cover facing the other side in the axial direction, and that faces the pump in the axial direction.

[0221] (13) The electric oil pump according to (12), wherein an end portion of the bottom plate portion on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion.

[0222] (14) The electric oil pump according to (12) or (13), wherein a surface of the pump cover facing the other side in the axial direction is provided with a second groove portion that is recessed toward the one side in the axial direction and extends in a circumferential direction, the bottom plate portion is provided with a second through hole extending through the bottom plate portion in the axial direction, and the second through hole at least partially overlaps the second groove portion as viewed in the axial direction.

[0223] (15) The electric oil pump according to any one of (12) to (14), wherein the pump cover is molded by insert molding using the bottom plate portion as an insert.

[0224] (16) The electric oil pump according to any one of (12) to (14), wherein the pump cover includes a cover protrusion portion protruding toward the other side in the axial direction, and the bottom plate portion is fitted to the cover protrusion portion.

[0225] (17) The electric oil pump according to (16), wherein the bottom plate portion is provided with a pair of second through holes extending through the bottom plate portion in the axial direction, as viewed in the axial direction, the pair of second through holes have shapes that are line-symmetrical to each other with respect to a virtual straight line passing through a center of the bottom plate portion as a line of symmetry, and the bottom plate portion includes a hole portion extending through the bottom plate portion in the axial direction at a position shifted from the virtual straight line.

[0226] (18) The electric oil pump according to any one of (1) to (17), wherein the electric oil pump is a positive displacement electric oil pump, the housing includes a pump cover that is made of resin and closes the accommodation recess portion from the one side in the axial direction, the housing body portion includes a first welded portion facing the pump cover, the first welded portion includes a first welded protrusion portion protruding toward the one side in the axial direction, the pump cover includes a second welded portion facing the housing body portion, the second welded portion includes a second welded protrusion portion protruding toward the other side in the axial direction, and the first welded protrusion portion and the second welded protrusion portion are welded to each other.

[0227] (19) The electric oil pump according to (18), wherein a size of the first welded protrusion portion in the radial direction is larger than a size of the first welded protrusion portion in the axial direction, and a size of the second welded protrusion portion in the radial direction is larger than a size of the second welded protrusion portion in the axial direction.

[0228] (20) The electric oil pump according to (18) or (19), wherein a portion of the second welded portion other than the second welded protrusion portion faces the first welded portion in the axial direction with a gap in between.

[0229] (21) The electric oil pump according to any one of (18) to (20), wherein the pump cover includes a cover protrusion portion protruding toward the other side in the axial direction, and the housing includes a bottom plate portion made of metal and fitted to the cover protrusion portion.

[0230] (22) The electric oil pump according to (21), wherein the second welded portion is located on the outer side in the radial direction of the bottom plate portion.

[0231] (23) The electric oil pump according to (21) or (22), wherein the bottom plate portion is in contact with the circumferential wall portion in the axial direction.

[0232] (24) The electric oil pump according to any one of (18) to (23), wherein the housing body portion includes a pump accommodation portion surrounding the pump from the outer side in the radial direction, and a motor accommodation portion that accommodates the motor and is provided more on the other side in the axial direction than the pump accommodation portion, a plurality of ribs are provided on a surface of the pump accommodation portion facing the outer side in the radial direction, and the plurality of ribs are spaced apart from each other along a circumferential direction, and connect in the axial direction, the motor accommodation portion on the one side in the axial direction and the first welded portion.

[0233] (25) The electric oil pump according to any one of (18) to (24) further including a circuit board that is provided more on the other side in the axial direction than the motor and supplies a current to the motor, wherein the housing includes a lid portion made of resin that accommodates the circuit board, the housing body portion includes a third welded portion facing the lid portion, the lid portion includes a fourth welded portion facing the third welded portion, and the third welded portion and the fourth welded portion are welded to each other.

[0234] (26) A housing body portion made of resin, the housing body portion at least partially accommodating a motor and a pump in a positive displacement electric oil pump, and being welded to a pump cover made of resin, the housing body portion having a cylindrical shape extending in an axial direction, the housing body portion including a first welded portion at an end portion in the axial direction, wherein the first welded portion includes a first welded protrusion portion protruding in the axial direction and welded to a second welded portion of the pump cover.

[0235] (27) A pump cover made of resin and welded to a housing body portion made of resin, the housing body portion at least partially accommodating a motor and a pump in a positive displacement electric oil pump, the pump cover including a second welded portion at an end portion in an axial direction, wherein the second welded portion includes a second welded protrusion portion protruding in the axial direction and welded to a first welded portion of the housing body portion.

[0236] Features of the above-described preferred example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

[0237] While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0026]Hereinafter, electric oil pumps according to example embodiments of the present disclosure will be described with reference to the drawings. The scope of the present disclosure is not limited to the following example embodiments, and can be arbitrarily changed within the scope of the technical ideas of the present disclosure. In the drawings described below, in order to make each configuration easy to understand, the scale, the number, and the like in each structure may be different from those in the actual structure.

[0027]In each drawing, a Z axis is illustrated as appropriate. The direction in which the Z axis extends is the direction in which a rotation axis J of the example embodiments described below extends. The rotation axis J in each diagram is a virtual axis. In the following description, the direction in which the rotation axis J extends, that is, a direction parallel to the Z axis is referred to as an “axial direction”. A side in the axial direction toward which an ...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2025-055812 filed on Mar. 28, 2025, and Japanese Patent Application No. 2025-148583 filed on Sep. 8, 2025, the entire contents of each application being incorporated herein by reference.1. FIELD OF THE INVENTION

[0002] The present disclosure relates to electric oil pumps, housings, and pump covers.2. BACKGROUND

[0003] An oil pump has been known that includes a resin motor housing that accommodates a motor having a rotating shaft, and a metal pump case that accommodates a pumping gear rotated by the rotating shaft, wherein the pump case is fixed to the motor housing using a plurality of locking pieces of the motor housing.SUMMARY

[0004] In the above-described oil pump, a difference in linear expansion coefficient is large between the resin motor housing and the metal pump case. Thus, there is a concern that when the temperature of the oil pump varies, a holding force of each of the locking pieces for holding the pump case may greatly vary. Accordingly, in the oil pump, when the temperature of the oil pump varies, the positional accuracy between the center axis of the motor and the center axis of the pumping gear may be compromised. This may result in huge loss of the driving force transmitted from the motor to the pumping gear. Therefore, with the oil pump, the flow rate of the oil discharged from the pump may be reduced.

[0005] An electric oil pump according to an example embodiment of the present disclosure includes a shaft extending in an axial direction, a motor including a rotor that is rotatably fixed to the shaft, and a stator facing the rotor with a gap in a radial direction, a pump to be driven to pump oil by power of the motor, and a housing accommodating the motor and the pump. The pump includes an inner rotor coupled to the shaft on one side in the axial direction and including external teeth, and an outer rotor surrounding the inner rotor from an outer side in the radial direction and including internal teeth meshing with the external teeth. The housing includes a housing body portion made of resin and a metal housing portion made of metal. The housing body portion includes an accommodation recess portion that is recessed from an end portion on one side in the axial direction toward another side in the axial direction and accommodates the pump, and a stator holding portion that holds the stator. The accommodation recess portion includes a recess portion inner circumferential surface surrounding the pump from the outer side in the radial direction. The metal housing portion is at least partially embedded in the housing body portion. The metal housing portion includes a cylindrical circumferential wall portion between the pump and the recess portion inner circumferential surface in the radial direction.

[0006] A housing body portion is made of resin, at least partially accommodates a motor and a pump in a positive displacement electric oil pump, and is welded to a pump cover made of resin, has a cylindrical shape extending in an axial direction, and includes a first welded portion at an end portion in the axial direction, and the first welded portion includes a first welded protrusion portion protruding in the axial direction and welded to a second welded portion of the pump cover.

[0007] A pump cover is made of resin and welded to a housing body portion made of resin, the housing body portion at least partially accommodates a motor and a pump in a positive displacement electric oil pump, the pump cover includes a second welded portion at an end portion in an axial direction, and the second welded portion includes a second welded protrusion portion protruding in the axial direction and welded to a first welded portion of the housing body portion.

[0008] The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a first perspective view illustrating an electric oil pump according to a first example embodiment of the present disclosure.

[0010] FIG. 2 is a cross-sectional view illustrating the electric oil pump according to the first example embodiment.

[0011] FIG. 3 is an enlarged cross-sectional view illustrating a portion of the electric oil pump according to the first example embodiment.

[0012] FIG. 4 is a cross-sectional view illustrating the electric oil pump according to the first example embodiment, taken along IV-IV in FIG. 3.

[0013] FIG. 5 is a second perspective view illustrating the electric oil pump according to the first example embodiment.

[0014] FIG. 6 is a plan view of a pump cover and a bottom plate portion according to the first example embodiment as viewed from the other side in an axial direction.

[0015] FIG. 7 is a perspective view illustrating a metal housing portion according to the first example embodiment.

[0016] FIG. 8 is a perspective view illustrating the bottom plate portion according to the first example embodiment.

[0017] FIG. 9 is a cross-sectional view illustrating the electric oil pump according to the first example embodiment, taken along IX-IX in FIG. 3.

[0018] FIG. 10 is a perspective view illustrating an electric oil pump according to a second example embodiment of the present disclosure.

[0019] FIG. 11 is a cross-sectional view illustrating the electric oil pump according to the second example embodiment.

[0020] FIG. 12 is a first enlarged cross-sectional view partially illustrating a portion of the electric oil pump according to the second example embodiment.

[0021] FIG. 13 is a cross-sectional view illustrating the electric oil pump according to the second example embodiment, taken along VIII-VIII in FIG. 12.

[0022] FIG. 14 is a plan view of a pump cover and a bottom plate portion according to the second example embodiment as viewed from the other side in an axial direction.

[0023] FIG. 15 is a second enlarged cross-sectional view illustrating a portion of the electric oil pump according to the second example embodiment.

[0024] FIG. 16 is a cross-sectional view illustrating the electric oil pump according to the second example embodiment, taken along XVI-XVI in FIG. 12.

[0025] FIG. 17 is a perspective view illustrating a metal housing portion according to the second example embodiment.DETAILED DESCRIPTION

[0026] Hereinafter, electric oil pumps according to example embodiments of the present disclosure will be described with reference to the drawings. The scope of the present disclosure is not limited to the following example embodiments, and can be arbitrarily changed within the scope of the technical ideas of the present disclosure. In the drawings described below, in order to make each configuration easy to understand, the scale, the number, and the like in each structure may be different from those in the actual structure.

[0027] In each drawing, a Z axis is illustrated as appropriate. The direction in which the Z axis extends is the direction in which a rotation axis J of the example embodiments described below extends. The rotation axis J in each diagram is a virtual axis. In the following description, the direction in which the rotation axis J extends, that is, a direction parallel to the Z axis is referred to as an “axial direction”. A side in the axial direction toward which an arrow of the Z axis points (+Z side) is referred to as “one side in the axial direction” or “lower side” and a side in the axial direction opposite to the side toward which the arrow of the Z axis points (−Z side) is referred to as “other side in the axial direction” or “upper side”. In the following description, a radial direction around the rotation axis J is simply referred to as “radial direction” and a circumferential direction around the rotation axis J is simply referred to as “circumferential direction”. Note that each of the upper side and the lower side is merely a name for describing a relative relationship and the like of the respective elements, and the relative positional relationship among the elements may be an arrangement relationship other than the arrangement relationship indicated by these names may be used.

[0028] The circumferential direction is indicated by an arrow θ in each drawing. The side (+θ side) to which the arrow θ points in the circumferential direction is referred to as “one side in the circumferential direction”. The side (−θ side) opposite to the side to which the arrow θ points in the circumferential direction is referred to as “the other side in the circumferential direction”. One side in the circumferential direction is a side of counterclockwise advancement around the rotation axis J as viewed from the upper side. The other side in the circumferential direction is a side of clockwise advancement around the rotation axis J as viewed from the upper side.

[0029] FIG. 1 is a perspective view illustrating an electric oil pump 1 of the present example embodiment. The electric oil pump 1 of the present example embodiment is an electric oil pump that feeds oil as a fluid. The fluid may be another liquid such as water. The electric oil pump 1 is used, for example, to supply oil to an attached body provided to a vehicle or the like. The attached body may be an automatic transmission or a drive device that drives an axle of a vehicle. As illustrated in FIG. 2, the electric oil pump 1 includes a housing 10, a motor 40, a shaft 43, a control device 56, and a pump 60.

[0030] The housing 10 has a substantially cylindrical shape extending in the axial direction. The housing 10 accommodates each of the motor 40, the shaft 43, the control device 56, and the pump 60. The housing 10 includes a housing body portion 11, a lid portion 21, a metal housing portion 25, a pump cover 31, and a bottom plate portion 37. In the present example embodiment, the housing body portion 11, the lid portion 21, and the metal housing portion 25, the pump cover 31, and the bottom plate portion 37 are separate members.

[0031] The housing body portion 11 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The housing body portion 11 accommodates each of the motor 40, the shaft 43, and the pump 60. In the present example embodiment, the housing body portion 11 is made of resin. As a material forming the housing body portion 11, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), or the like can be used. In the present example embodiment, the housing body portion 11 is molded by insert molding using the metal housing portion 25 and a stator 50 (described later) of the motor 40 as inserts. The metal housing portion 25 is at least partially embedded in the housing body portion 11. Thus, the metal housing portion 25 is fixed to the housing body portion 11. Therefore, in the assembly process for the electric oil pump 1, it is not necessary to fix the metal housing portion 25 to the housing body portion 11 using, for example, an adhesive, and thus it is possible to suppress an increase in the number of assembly steps of the electric oil pump 1. The stator 50 is embedded in the housing body portion 11. The housing body portion 11 includes a motor accommodation portion 12, a pump accommodation portion 16, and a rib 20.

[0032] The motor accommodation portion 12 is an upper side portion of the housing body portion 11. The motor accommodation portion 12 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The motor accommodation portion 12 is open on the upper side. The motor accommodation portion 12 accommodates the motor 40. The motor accommodation portion 12 includes a first side wall portion 12a, a stator holding portion 12g, and an attachment portion 14.

[0033] The first side wall portion 12a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The first side wall portion 12a surrounds an upper side portion of each of the motor 40 and the shaft 43 from the outer side in the radial direction. The lid portion 21 is fixed to the upper end of the first side wall portion 12a. The first side wall portion 12a is provided with a first annular groove portion 12c and a first projection portion 12e.

[0034] The first annular groove portion 12c is a groove that is recessed toward the inner side in the radial direction from the surface of the first side wall portion 12a facing the outer side in the radial direction and extends in the circumferential direction. The first annular groove portion 12c extends over the entire circumference in the circumferential direction. An O-ring 91 is fitted in the first annular groove portion 12c. The first projection portion 12e is a projection protruding toward the upper side from the surface of the first side wall portion 12a facing the upper side. The first projection portion 12e extends over the entire circumference in the circumferential direction.

[0035] The stator holding portion 12g has a substantially annular shape that is centered on the rotation axis J. The stator holding portion 12g is provided more on the inner side in the radial direction than the first side wall portion 12a. The stator holding portion 12g is connected to the first side wall portion 12a. The stator 50 (described later) of the motor 40 is embedded in the stator holding portion 12g. Therefore, the housing body portion 11 holds the stator 50. The stator holding portion 12g is provided with a board holding portion 12h.

[0036] The board holding portion 12h has a columnar shape protruding toward the upper side from the surface of the stator holding portion 12g facing the upper side. Although not elaborated in the figures, the stator holding portion 12g is provided with a plurality of the board holding portions 12h. The board holding portions 12h are spaced apart from each other in the circumferential direction.

[0037] The attachment portion 14 protrudes toward the outer side in the radial direction from the surface of the first side wall portion 12a facing the outer side in the radial direction. The attachment portion 14 is provided with a hole portion 14a extending through the attachment portion 14 in the axial direction. As illustrated in FIG. 1, in the present example embodiment, the motor accommodation portion 12 includes two attachment portions 14. The number of the attachment portions 14 included in the motor accommodation portion 12 may be three or more. The attachment portions 14 face each other in the radial direction with the rotation axis J interposed therebetween. A collar portion 14c is inserted in each of the hole portions 14a. Each collar portion 14c is fixed to the inner circumferential surface of the hole portion 14a. Each collar portion 14c is made of metal. As illustrated in FIG. 2, the collar portion 14c has a substantially cylindrical shape extending in the axial direction. When a bolt (not illustrated) is passed through the inside of each collar portion 14c in the axial direction and is fastened into a female screw hole of an attached body (not illustrated), each attachment portion 14 is fixed to the attached body. That is, the electric oil pump 1 is fixed to the attached body.

[0038] As illustrated in FIG. 1, the pump accommodation portion 16 is a lower side portion of the housing body portion 11. The pump accommodation portion 16 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. As illustrated in FIG. 3, the surface of the pump accommodation portion 16 facing the lower side is a lower end portion of the housing body portion 11. The pump accommodation portion 16 has an opening portion 17c that is open on the lower side, that is, one side (+Z side) in the axial direction. The pump accommodation portion 16 accommodates the pump 60. The pump accommodation portion 16 includes a second side wall portion 16a and an annular wall portion 18. The pump accommodation portion 16 is provided with an accommodation recess portion 17. Thus, the housing body portion 11 includes the accommodation recess portion 17.

[0039] The second side wall portion 16a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The second side wall portion 16a surrounds a lower side portion of each of the pump 60 and the shaft 43 from the outer side in the radial direction. The pump cover 31 is fixed to the lower end of the second side wall portion 16a. As illustrated in FIG. 1, the outer diameter of the second side wall portion 16a is smaller than the outer diameter of the first side wall portion 12a. As illustrated in FIG. 3, the second side wall portion 16a is provided with a second projection portion 16c. The second projection portion 16c is a projection that protrudes toward the lower side from the surface of the second side wall portion 16a facing the lower side. The second projection portion 16c extends over the entire circumference in the circumferential direction.

[0040] The accommodation recess portion 17 is a hole that is recessed toward the upper side from the surface of the pump accommodation portion 16 facing the lower side. That is, the accommodation recess portion 17 is a hole that is recessed from the end portion of the housing body portion 11 on the lower side, that is, the one side (+Z side) in the axial direction toward the upper side, that is, the other side (−Z side) in the axial direction. The accommodation recess portion 17 accommodates the pump 60. The accommodation recess portion 17 includes a recess portion inner circumferential surface 17a and a top surface 17e. Thus, the pump accommodation portion 16 includes the top surface 17e.

[0041] The recess portion inner circumferential surface 17a is a surface, of the inner surface of the accommodation recess portion 17, facing the inner side in the radial direction. As illustrated in FIG. 4, the recess portion inner circumferential surface 17a has a substantially circular shape surrounding the rotation axis J. As viewed in the axial direction, the center of the recess portion inner circumferential surface 17a is shifted from the rotation axis J. As illustrated in FIG. 3, the recess portion inner circumferential surface 17a faces the pump 60 in the radial direction. The recess portion inner circumferential surface 17a surrounds the pump 60 from the outer side in the radial direction. The opening portion 17c is the lower end of the recess portion inner circumferential surface 17a.

[0042] The top surface 17e is a surface, of the inner surface of the accommodation recess portion 17, facing the lower side. The top surface 17e is a surface, of the annular wall portion 18, facing the lower side. The top surface 17e is located more on the upper side, that is, the other side (−Z side) in the axial direction than the pump 60. The top surface 17e faces the pump 60 in the axial direction.

[0043] The annular wall portion 18 has a substantially annular shape centered on the rotation axis J. The end portion of the annular wall portion 18 on the outer side in the radial direction is connected to the inner circumferential surface of the second side wall portion 16a over the entire circumference in the circumferential direction. The annular wall portion 18 is provided more on the lower side than the motor 40 and more on the upper side than the pump 60. As described above, the top surface 17e is the surface of the annular wall portion 18 facing the lower side. The annular wall portion 18 is provided with an inner tubular portion 18a, a communication hole portion 18c, an outflow hole 18e, a communication groove portion 18g, and a first groove portion 19. Therefore, the housing body portion 11 includes the communication hole portion 18c. The top surface 17e is provided with each of the communication groove portion 18g and the first groove portion 19.

[0044] The inner tubular portion 18a protrudes toward the upper side from the inner edge of the annular wall portion 18 in the radial direction. The inner tubular portion 18a has a substantially cylindrical shape that is centered on the rotation axis J. The inner circumferential surface of the inner tubular portion 18a is connected to the inner circumferential surface of the annular wall portion 18 in the axial direction.

[0045] The communication hole portion 18c is a hole extending through each of the annular wall portion 18 and the inner tubular portion 18a in the axial direction. The communication hole portion 18c is formed by the inner circumferential surface of the annular wall portion 18 and the inner circumferential surface of the inner tubular portion 18a. As viewed in the axial direction, the communication hole portion 18c has a substantially circular shape centered on the rotation axis J. The communication hole portion 18c connects the inside of the motor accommodation portion 12 and the inside of the accommodation recess portion 17. Thus, the communication hole portion 18c connects the inside of the motor accommodation portion 12 and the inside of the pump accommodation portion 16. The shaft 43 passes through the inside of the communication hole portion 18c in the axial direction. The outflow hole 18e is a hole extending through the annular wall portion 18 in the axial direction. The outflow hole 18e is provided in a portion on the outer side of the annular wall portion 18 in the radial direction.

[0046] The first groove portion 19 is a groove recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the top surface 17e. The first groove portion 19 is open on the lower side. In the present example embodiment, the top surface 17e is provided with two first groove portions 19. The two first groove portions 19 include a first suction-side groove portion 19a and a first discharge-side groove portion 19c.

[0047] As illustrated in FIG. 4, each of the first suction-side groove portion 19a and the first discharge-side groove portion 19c is a substantially arc-shaped groove extending in the circumferential direction as viewed in the axial direction. That is, the first groove portion 19 is a groove extending in the circumferential direction. The first suction-side groove portion 19a and the first discharge-side groove portion 19c are provided at different positions in the circumferential direction. The first suction-side groove portion 19a and the first discharge-side groove portion 19c face each other in the radial direction. More specifically, the first suction-side groove portion 19a and the first discharge-side groove portion 19c face each other in the radial direction, with the rotation axis J interposed therebetween. As illustrated in FIGS. 3 and 4, the first suction-side groove portion 19a overlaps the outflow hole 18e as viewed in the axial direction. As illustrated in FIG. 3, the outflow hole 18e connects the inside of the motor accommodation portion 12 and the inside of the first suction-side groove portion 19a.

[0048] The communication groove portion 18g is a groove recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the top surface 17e. As illustrated in FIG. 4, the communication groove portion 18g extends linearly along the radial direction. The communication groove portion 18g has the end portion, on the inner side in the radial direction, open to the communication hole portion 18c. In the present example embodiment, the end portion of the communication groove portion 18g on the outer side in the radial direction is open to the first discharge-side groove portion 19c. Accordingly, in the present example embodiment, the communication groove portion 18g connects the communication hole portion 18c and the first discharge-side groove portion 19c. That is, the communication groove portion 18g connects the communication hole portion 18c and the first groove portion 19. The end portion of the communication groove portion 18g on the inner side in the radial direction may be open to the annular wall portion 18, and the end portion of the communication groove portion 18g on the outer side in the radial direction may be open to the first suction-side groove portion 19a. In this case, the communication groove portion 18g connects the communication hole portion 18c and the first suction-side groove portion 19a. That is, the communication groove portion 18g connects the communication hole portion 18c and the first groove portion 19.

[0049] As illustrated in FIG. 1, the rib 20 is provided on the outer circumferential surface of the second side wall portion 16a, that is, a surface facing the outer side of the pump accommodation portion 16 in the radial direction. As described above, in the present example embodiment, the housing body portion 11 is made of resin. Therefore, it is difficult to improve the strength of the housing body portion 11 as compared with the case where the housing body portion 11 is made of metal. In contrast, in the present example embodiment, the rib 20 is provided on the surface of the pump accommodation portion 16 facing the outer side in the radial direction, and thus the strength of the housing body portion 11 can be suitably improved. The rib 20 has a plate shape protruding toward the outer side in the radial direction from the pump accommodation portion 16. The plate surface of the rib 20 faces the circumferential direction. The rib 20 extends in the axial direction. The upper end of the rib 20 is connected to the first side wall portion 12a. That is, the rib 20 is connected to the motor accommodation portion 12. The housing body portion 11 includes a plurality of the ribs 20. In the present example embodiment, the housing body portion 11 includes four ribs 20. The number of ribs 20 included in housing body portion 11 may be three or less, or may be five or more. The ribs 20 are disposed at an interval along the circumferential direction. In the present example embodiment, the ribs 20 are disposed at a substantially equal interval along the circumferential direction. Therefore, it is possible to suitably reduce the variation in the strength of the housing body portion 11 in the circumferential direction. As illustrated in FIG. 5, the plurality of ribs 20 include a first rib 20a and a second rib 20c. In the present example embodiment, the plurality of ribs 20 include one first rib 20a and three second ribs 20c. The number of the first ribs 20a and the number of the second ribs 20c included in the plurality of ribs 20 are not limited to those in the present example embodiment.

[0050] The first rib 20a and each second rib 20c are provided on the surface of the pump accommodation portion 16 facing the outer side in the radial direction. Each of the first rib 20a and the second ribs 20c extends in the axial direction. The second ribs 20c and the first rib 20a are spaced apart from each other in the circumferential direction. The first rib 20a has the end portion on the lower side, that is, the one side (+Z side) in the axial direction located more on the lower side than the lower end portion of each of the plurality of second ribs 20c.

[0051] As illustrated in FIG. 2, the lid portion 21 has a substantially cylindrical shape that is centered on the rotation axis J and protrudes in the axial direction. The lid portion 21 is open on the lower side. The lid portion 21 is fixed to the upper end of the housing body portion 11. The lid portion 21 closes the upper side opening of the motor accommodation portion 12. The internal space of the lid portion 21 and the internal space of the motor accommodation portion 12 are connected to each other. The control device 56 is accommodated in the lid portion 21. In the present example embodiment, the lid portion 21 is made of resin. As a material forming the lid portion 21, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), or the like can be used. The lid portion 21 may be made of another material such as a metal material. The lid portion 21 includes a lid circumferential wall portion 22 and a board cover portion 23.

[0052] The lid circumferential wall portion 22 has a substantially cylindrical shape that is centered on the rotation axis J and protrudes in the axial direction. The lid circumferential wall portion 22 surrounds the control device 56 from the outer side in the radial direction. The lid circumferential wall portion 22 is provided with a second annular groove portion 22a. The second annular groove portion 22a is a groove that is recessed toward the upper side from the surface of the lid circumferential wall portion 22 facing the lower side and extends over the entire circumference in the circumferential direction. The first projection portion 12e of the motor accommodation portion 12 is inserted in the second annular groove portion 22a. Therefore, the lid portion 21 is positioned in the radial direction with respect to the housing body portion 11. In the present example embodiment, the lower end of the lid circumferential wall portion 22 and the upper end of the first side wall portion 12a are joined to each other by welding over the entire circumference in the circumferential direction. Therefore, the section between the housing body portion 11 and the lid portion 21 can be suitably sealed, and thus the airtightness of the electric oil pump 1 can be suitably improved. Further, since it is not necessary to separately provide a sealing member such as an O-ring for sealing between the housing body portion 11 and the lid portion 21, it is possible to suppress an increase in the number of components of the electric oil pump 1.

[0053] As illustrated in FIG. 1, the board cover portion 23 has a substantially disk shape centered on the rotation axis J. As illustrated in FIG. 2, the board cover portion 23 is provided more on the upper side than the control device 56. The outer edge of the board cover portion 23 in the radial direction is connected to the upper end of the lid circumferential wall portion 22.

[0054] As illustrated in FIG. 3, the pump cover 31 has a substantially annular shape centered on the rotation axis J. The pump cover 31 is provided more on lower side in the axial direction than the pump 60. The pump cover 31 is fixed to a lower end of the pump accommodation portion 16. The pump cover 31 covers the pump 60 from the lower side. The pump cover 31 closes the accommodation recess portion 17 from the lower side, that is, from the one side (+Z side) in the axial direction. That is, the pump cover 31 closes the opening portion 17c from the lower side. In the present example embodiment, the pump cover 31 is made of resin. As a material forming the pump cover 31, polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), or the like can be used. The pump cover 31 may be made of another material such as a metal material. In the present example embodiment, the pump cover 31 is molded by insert molding using the bottom plate portion 37 as an insert. Therefore, the bottom plate portion 37 is fixed to the pump cover 31. Therefore, in the assembly process for the electric oil pump 1, it is not necessary to fix the bottom plate portion 37 to the pump cover 31 using, for example, an adhesive, and thus it is possible to more suitably suppress an increase in the number of assembly steps of the electric oil pump 1. The pump cover 31 includes a cover body portion 32 and a protruding tubular portion 35.

[0055] The cover body portion 32 is an upper side portion of the pump cover 31. The cover body portion 32 has a substantially annular shape centered on the rotation axis J. The cover body portion 32 is provided with a suction port 32a, a discharge hole portion 32b, a discharge port 32c, a third annular groove portion 32e, and a second groove portion 33. Thus, the pump cover 31 is provided with the second groove portion 33. As illustrated in FIG. 5, the cover body portion 32 is provided with a protrusion portion 34. That is, the pump cover 31 is provided with the protrusion portion 34.

[0056] As illustrated in FIG. 3, the suction port 32a is an opening provided in the surface of the cover body portion 32 facing the lower side. The suction port 32a is open on the lower side. Although not elaborated in the figures, the suction port 32a has an arc shape extending in the circumferential direction as viewed in the axial direction. As described later, the suction port 32a is connected to the bottom surface of a second suction-side groove portion 33a. Oil outside the electric oil pump 1 is sucked into the housing 10 through the suction port 32a.

[0057] The discharge hole portion 32b is a hole extending toward the inner side in the radial direction from the surface of the cover body portion 32 facing the outer side in the radial direction. As described later, the end portion of the discharge hole portion 32b on the inner side in the radial direction is connected to a second discharge-side groove portion 33c. As illustrated in FIG. 1, the discharge hole portion 32b is open on the outer side in the radial direction. The discharge port 32c is an opening located at the end portion of the discharge hole portion 32b on the outer side in the radial direction. The discharge port 32c is provided in the surface of the pump cover 31 facing the outer side in the radial direction. As illustrated in FIG. 3, the oil compressed in the pump 60 is discharged to the outside of the electric oil pump 1 through the discharge hole portion 32b and the discharge port 32c.

[0058] The third annular groove portion 32e is a groove that is recessed toward the lower side from the surface of the cover body portion 32 facing the upper side and extends over the entire circumference in the circumferential direction. The second projection portion 16c of the pump accommodation portion 16 is inserted in the third annular groove portion 32e. Thus, the pump cover 31 is positioned in the radial direction with respect to the housing body portion 11. In the present example embodiment, the lower end of the second side wall portion 16a and the upper end of the cover body portion 32 are joined to each other by welding over the entire circumference in the circumferential direction. That is, the pump accommodation portion 16 and the pump cover 31 are joined to each other by welding over the entire circumference in the circumferential direction. Therefore, the section between the housing body portion 11 and the pump cover 31 can be suitably sealed, and thus the airtightness of the electric oil pump 1 can be suitably improved. Further, since it is not necessary to separately provide a sealing member such as an O-ring for sealing between the housing body portion 11 and the pump cover 31, it is possible to suppress an increase in the number of components of the electric oil pump 1.

[0059] The second groove portion 33 is a groove recessed toward the lower side from the surface of the cover body portion 32 facing the upper side. As illustrated in FIG. 6, the second groove portion 33 extends in the circumferential direction. That is, the second groove portion 33 that is recessed toward the lower side, that is, the one side (+Z side) in the axial direction and extends in the circumferential direction is provided in the surface of the pump cover 31 on the upper side, that is, the other side (−Z side) in the axial direction. As illustrated in FIG. 3, the second groove portion 33 is open on the upper side. In the present example embodiment, the cover body portion 32 is provided with two second groove portions 33. Thus, the pump cover 31 is provided with two second groove portions 33. The two second groove portions 33 include the second suction-side groove portion 33a and the second discharge-side groove portion 33c.

[0060] As illustrated in FIG. 6, each of the second suction-side groove portion 33a and the second discharge-side groove portion 33c is an arc-shaped groove extending in the circumferential direction as viewed in the axial direction. That is, the second groove portion 33 is a groove extending in the circumferential direction. The second suction-side groove portion 33a and the second discharge-side groove portion 33c are provided at different positions in the circumferential direction. The second suction-side groove portion 33a and the second discharge-side groove portion 33c face each other in the radial direction. Thus, the two second groove portions 33 face each other in the radial direction. More specifically, the second suction-side groove portion 33a and the second discharge-side groove portion 33c face each other in the radial direction, with the rotation axis J interposed therebetween.

[0061] As illustrated in FIG. 6, the second suction-side groove portion 33a overlaps the suction port 32a as viewed in the axial direction. The inside of the second suction-side groove portion 33a is connected to the suction port 32a. The second suction-side groove portion 33a overlaps the first suction-side groove portion 19a as viewed in the axial direction. As illustrated in FIGS. 4 and 6, the second suction-side groove portion 33a and the first suction-side groove portion 19a have substantially the same shape as viewed in the axial direction.

[0062] As illustrated in FIG. 3, the second discharge-side groove portion 33c is connected to the discharge hole portion 32b. Therefore, the inside of the second discharge-side groove portion 33c is connected to the discharge port 32c through the discharge hole portion 32b. The second discharge-side groove portion 33c overlaps the first discharge-side groove portion 19c as viewed in the axial direction. As illustrated in FIGS. 4 and 6, the second discharge-side groove portion 33c and the first discharge-side groove portion 19c have substantially the same shape as viewed in the axial direction.

[0063] As illustrated in FIGS. 5 and 6, the protrusion portion 34 protrudes toward the outer side in the radial direction from the upper end of the surface of the cover body portion 32 facing the outer side in the radial direction. As viewed in the axial direction, the protrusion portion 34 has a substantially trapezoidal shape with a long side located on the inner side in the radial direction and a short side located on the outer side in the radial direction. The protrusion portion 34 overlaps the first rib 20a as viewed in the axial direction. The protrusion portion 34 is provided with a positioning portion 34a.

[0064] The positioning portion 34a is a hole that is recessed toward the lower side, that is, the one side (+Z side) in the axial direction from the surface of the protrusion portion 34 facing the upper side, that is, the other side (−Z side) in the axial direction. In the present example embodiment, the positioning portion 34a is provided through the protrusion portion 34 in the axial direction. The positioning portion 34a may not be provided through the protrusion portion 34 in the axial direction. As illustrated in FIG. 6, in the present example embodiment, the positioning portion 34a is open on the outer side in the radial direction. That is, the positioning portion 34a is open in the radial direction. The positioning portion 34a may not be open in the radial direction. As illustrated in FIG. 5, a portion of the first rib 20a on the one side in the axial direction is located inside the positioning portion 34a. In the present example embodiment, the positioning portion 34a is fitted with the first rib 20a. Therefore, the positional accuracy of the pump cover 31 in the circumferential direction with respect to the housing body portion 11 can be improved.

[0065] As illustrated in FIG. 3, the protruding tubular portion 35 protrudes toward the lower side from the lower end of the cover body portion 32. The protruding tubular portion 35 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The protruding tubular portion 35 is provided with a fourth annular groove portion 35a. The fourth annular groove portion 35a is a groove that is recessed toward the inner side in the radial direction from the surface of the protruding tubular portion 35 facing the outer side in the radial direction and extends in the circumferential direction. The fourth annular groove portion 35a extends over the entire circumference in the circumferential direction. An O-ring 92 is fitted in the fourth annular groove portion 35a.

[0066] The metal housing portion 25 is accommodated in the housing body portion 11. As described above, the metal housing portion 25 is fixed to the housing body portion 11. As described above, the metal housing portion 25 is at least partially embedded in the housing body portion 11. In the present example embodiment, the metal housing portion 25 is made of metal. As a material forming the metal housing portion 25, aluminum, stainless steel, or the like can be used. As described above, in the present example embodiment, the housing body portion 11 is made of resin. Therefore, the linear expansion coefficient of the metal housing portion 25 is smaller than the linear expansion coefficient of the housing body portion 11. As illustrated in FIG. 7, the metal housing portion 25 includes a circumferential wall portion 26, a top wall portion 27, and a tubular portion 29.

[0067] The circumferential wall portion 26 has a tubular shape extending in the axial direction. More specifically, the circumferential wall portion 26 has a substantially cylindrical shape surrounding the rotation axis J. As illustrated in FIG. 4, as viewed in the axial direction, the center of the circumferential wall portion 26 substantially matches the center of the recess portion inner circumferential surface 17a. As illustrated in FIG. 3, the circumferential wall portion 26 is open on the lower side. The circumferential wall portion 26 is disposed in the accommodation recess portion 17. The circumferential wall portion 26 is fixed to the recess portion inner circumferential surface 17a. The circumferential wall portion 26 has a portion on the outer side in the radial direction embedded in the second side wall portion 16a. The circumferential wall portion 26 surrounds the pump 60 from the outer side in the radial direction. In the radial direction, the circumferential wall portion 26 is between the pump 60 and the recess portion inner circumferential surface 17a. The upper end of the circumferential wall portion 26 is in contact with the top surface 17e. The lower end of the circumferential wall portion 26 is located at substantially the same position as the lower end of the pump accommodation portion 16 in the axial direction.

[0068] As illustrated in FIG. 7, the top wall portion 27 has a substantially annular plate shape expanding in the radial direction. The top wall portion 27 has a plate shape that expands toward the outer side in the radial direction from the end portion of the tubular portion 29 on the lower side, that is, the one side (+Z side) in the axial direction. The top wall portion 27 surrounds the rotation axis J. The end portion of the circumferential wall portion 26 on the upper side, that is, the other side (−Z side) in the axial direction is connected to the end portion of the top wall portion 27 on the outer side in the radial direction over the entire circumference in the circumferential direction. Therefore, in the present example embodiment, the circumferential wall portion 26 and the top wall portion 27 are integrally formed, whereby the number of components of the metal housing portion 25 can be reduced as compared with a case where the circumferential wall portion 26 and the top wall portion 27 are separate members. Therefore, it is possible to suppress an increase in the manufacturing steps for the electric oil pump 1.

[0069] As illustrated in FIG. 3, the top wall portion 27 is disposed in the accommodation recess portion 17. That is, the top wall portion 27 is disposed in the pump accommodation portion 16. An upper side portion of the top wall portion 27 is embedded in the annular wall portion 18. The top wall portion 27 is fixed to the top surface 17e. The top surface 17e is located more on the upper side than the top wall portion 27 and faces the top wall portion 27 in the axial direction. The surface of the top wall portion 27 facing the lower side is located more on the lower side than the top surface 17e. The top wall portion 27 is between the pump 60 and the top surface 17e in the axial direction. As illustrated in FIG. 7, the top wall portion 27 is provided with the first through hole 28 and a second notch portion 27a.

[0070] The first through hole 28 is a hole extending through the top wall portion 27 in the axial direction. In the present example embodiment, the top wall portion 27 is provided with two first through holes 28. The two first through holes 28 include a first suction-side through hole 28a and a first discharge-side through hole 28c.

[0071] As viewed in the axial direction, each of the first suction-side through hole 28a and the first discharge-side through hole 28c has a substantially arc shape extending in the circumferential direction. That is, the first through hole 28 is a hole extending in the circumferential direction. The first suction-side through hole 28a and the first discharge-side through hole 28c are provided at different positions in the circumferential direction. The first suction-side through hole 28a and the first discharge-side through hole 28c face each other in the radial direction. More specifically, the first suction-side through hole 28a and the first discharge-side through hole 28c face each other in the radial direction with the rotation axis J interposed therebetween.

[0072] As illustrated in FIG. 4, the first suction-side through hole 28a surrounds the first suction-side groove portion 19a as viewed in the axial direction. Therefore, the first suction-side through hole 28a at least partially overlaps the first suction-side groove portion 19a. That is, the first through hole 28 at least partially overlaps the first groove portion 19. Therefore, as illustrated in FIG. 3, the inside of the first suction-side groove portion 19a is connected to the inside of the accommodation recess portion 17 through the first suction-side through hole 28a. The top surface 17e is partially exposed on the lower side through the first suction-side through hole 28a.

[0073] As illustrated in FIG. 4, the first discharge-side through hole 28c surrounds the first discharge-side groove portion 19c as viewed in the axial direction. Therefore, the first discharge-side through hole 28c at least partially overlaps the first discharge-side groove portion 19c. That is, the first through hole 28 at least partially overlaps the first groove portion 19. Therefore, as illustrated in FIG. 3, the inside of the first discharge-side through hole 19c is connected to the inside of the accommodation recess portion 17 through the first discharge-side groove portion 28c. As described above, the inside of the first suction-side groove portion 19a is connected to the inside of the accommodation recess portion 17 through the first suction-side through hole 28a. Accordingly, the inside of the first groove portion 19 is connected to the inside of the accommodation recess portion 17 through the first through hole 28. The top surface 17e is partially exposed on the lower side through the first discharge-side through hole 28c.

[0074] As illustrated in FIG. 7, the second notch portion 27a is a notch extending through the top wall portion 27 in the axial direction. The second notch portion 27a extends in the radial direction. In the present example embodiment, one end of the second notch portion 27a, which is the end portion on the outer side in the radial direction, is connected to the first discharge-side through hole 28c. That is, one end of the second notch portion 27a is connected to the first through hole 28. The second notch portion 27a may have one end on the outer side in the radial direction connected to the first suction-side through hole 28a. The second notch portion 27a has the other end that is the end portion on the inner side in the radial direction reaching the inner edge of the top wall portion 27 in the radial direction. Thus, the second notch portion 27a opens on the inner side in the radial direction. As illustrated in FIGS. 3 and 4, the communication groove portion 18g of the annular wall portion 18 at least partially overlaps the second notch portion 27a as viewed in the axial direction. Therefore, the inside of the accommodation recess portion 17 and the inside of the communication groove portion 18g are connected through the second notch portion 27a.

[0075] As illustrated in FIG. 7, the tubular portion 29 has a tubular shape extending toward the upper side, that is, the other side (−Z side) in the axial direction from the inner edge of the top wall portion 27 in the radial direction. More specifically, the top wall portion 27 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. As illustrated in FIG. 3, the tubular portion 29 is disposed in the communication hole portion 18c. The shaft 43 passes through the inside of the tubular portion 29 in the axial direction. The tubular portion 29 is between the shaft 43 and the inner circumferential surface of the communication hole portion 18c in the radial direction. The shaft 43 is supported by the tubular portion 29 to be rotatable about the rotation axis J. Therefore, since it is possible to suppress a direct contact between the shaft 43 and the communication hole portion 18c made of resin, wearing of the communication hole portion 18c can be suppressed while the electric oil pump 1 is operating. As illustrated in FIG. 7, the tubular portion 29 is provided with a first notch portion 29a.

[0076] The first notch portion 29a is a notch extending through part of the tubular portion 29 in the circumferential direction, in the radial direction. The first notch portion 29a extends in the axial direction. The lower end of the first notch portion 29a reaches the lower end of the tubular portion 29. Therefore, the first notch portion 29a is open on the lower side, that is, the one side (+Z side) in the axial direction. Therefore, as illustrated in FIG. 3, the inside of the tubular portion 29 is connected to the inside of the accommodation recess portion 17 through the first notch portion 29a. That is, the inside of the tubular portion 29 is connected to the inside of the pump accommodation portion 16 through the first notch portion 29a.

[0077] As illustrated in FIG. 7, the other end which is the end portion of the second notch portion 27a on the inner side in the radial direction, is connected to the lower end of the first notch portion 29a. As described above, one end of the second notch portion 27a is connected to the first discharge-side through hole 28c. As described above, the inside of the first discharge-side through hole 28c is connected to the inside of the accommodation recess portion 17 through the first discharge-side groove portion 19c. Thus, as illustrated in FIG. 3, the inside of the tubular portion 29 is connected to the inside of the first discharge-side groove portion 19c and the inside of the accommodation recess portion 17 through the second notch portion 27a and the first notch portion 29a. As illustrated in FIG. 4, the inside of the first notch portion 29a is connected to the inside of the communication groove portion 18g. As described above, the communication groove portion 18g connects the communication hole portion 18c and the first discharge-side groove portion 19c. Therefore, as illustrated in FIG. 3, the inside of the tubular portion 29 is connected to the inside of the first discharge-side groove portion 19c and the inside of the accommodation recess portion 17 through the second notch portion 27a, the communication groove portion 18g, and the first notch portion 29a.

[0078] As illustrated in FIG. 8, the bottom plate portion 37 has a substantially annular plate shape expanding in the radial direction. The bottom plate portion 37 surrounds the rotation axis J. As illustrated in FIG. 3, the bottom plate portion 37 is fixed to the surface of the pump cover 31 on the upper side, that is, the other side (−Z side) in the axial direction. The bottom plate portion 37 is provided more on the lower side than the pump 60. The bottom plate portion 37 faces the pump 60 in the axial direction. In the present example embodiment, the bottom plate portion 37 is in contact with the circumferential wall portion 26 of the metal housing portion 25 in the axial direction. Therefore, it is possible to suppress direct contact between each of an inner rotor 61 and an outer rotor 62 from coming into direct contact and the pump cover 31 made of resin. The bottom plate portion 37 may face the circumferential wall portion 26 with a gap in between in the axial direction. The end portion of the bottom plate portion 37 on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion 26. In the present example embodiment, the bottom plate portion 37 is made of metal. As a material forming the bottom plate portion 37, aluminum, stainless steel, or the like can be used. As illustrated in FIG. 8, the bottom plate portion 37 is provided with a plurality of hole portions 37a and a second through hole 38.

[0079] Each of the hole portions 37a is a hole extending through the bottom plate portion 37 in the axial direction. In the present example embodiment, the bottom plate portion is provided with six hole portions 37a. The hole portions 37a are provided at a substantially equal interval along the circumferential direction. Although not elaborated in the figures, the pump cover 31 partially enters each of the hole portions 37a. Therefore, it is possible to suitably suppress the variation of the position in the radial direction and the position in the circumferential direction of the bottom plate portion 37 with respect to the pump cover 31, and to increase the holding force of the pump cover 31 for holding the bottom plate portion 37.

[0080] The second through hole 38 is a hole extending through the bottom plate portion 37 in the axial direction. In the present example embodiment, the bottom plate portion 37 is provided with two second through holes 38. The two second through holes 38 include a second suction-side through hole 38a and a second discharge-side through hole 38c.

[0081] As viewed in the axial direction, each of the second suction-side through hole 38a and the second discharge-side through hole 38c has a substantially arc shape extending in the circumferential direction. That is, the second through hole 38 is a hole extending in the circumferential direction. The second suction-side through hole 38a and the second discharge-side through hole 38c are provided at different positions in the circumferential direction. The second suction-side through hole 38a and the second discharge-side through hole 38c face each other in the radial direction. More specifically, the second suction-side through hole 38a and the second discharge-side through hole 38c face each other in the radial direction with the rotation axis J interposed therebetween.

[0082] As illustrated in FIG. 6, the second suction-side through hole 38a surrounds the second suction-side groove portion 33a as viewed in the axial direction. Therefore, the second suction-side through hole 38a at least partially overlaps the second suction-side groove portion 33a. That is, the second through hole 38 at least partially overlaps the second groove portion 33. Therefore, as illustrated in FIG. 3, the inside of the second suction-side groove portion 33a is connected to the inside of the accommodation recess portion 17 through the second suction-side through hole 38a.

[0083] As illustrated in FIG. 6, the second discharge-side through hole 38c surrounds the second discharge-side groove portion 33c as viewed in the axial direction. Therefore, the second discharge-side through hole 38c at least partially overlaps the second discharge-side groove portion 33c. That is, the second through hole 38 at least partially overlaps the second groove portion 33. Therefore, as illustrated in FIG. 3, the inside of the second discharge-side groove portion 33c is connected to the inside of the accommodation recess portion 17 through the second discharge-side through hole 38c. As described above, the inside of the second suction-side groove portion 33a is connected to the inside of the accommodation recess portion 17 through the second suction-side through hole 38a. Accordingly, the inside of the second groove portion 33 is connected to the inside of the accommodation recess portion 17 through the second through hole 38.

[0084] As illustrated in FIG. 2, the motor 40 is accommodated in the housing body portion 11. More specifically, the motor 40 is accommodated in the motor accommodation portion 12. In the axial direction, the motor 40 is provided more on the lower side in the axial direction than the control device 56 and more on the upper side in the axial direction than the pump 60. The motor 40 includes a rotor 41 and the stator 50.

[0085] The rotor 41 is rotatable. In the present example embodiment, the rotor 41 is rotatable about the rotation axis J. The rotor 41 may be rotatable about a virtual axis extending in the axial direction different from the rotation axis J. The rotor 41 includes a rotor core 41a and a magnet 41b. The rotor core 41a has a substantially annular shape centered on the rotation axis J. The magnet 41b is fixed to the rotor core 41a.

[0086] The stator 50 is provided more on the outer side in the radial direction than the rotor 41. The stator 50 faces the rotor 41 in the radial direction with a gap in between. As described above, in the present example embodiment, the stator 50 is embedded inside the stator holding portion 12g. Therefore, the housing body portion 11 holds the stator 50. The stator 50 includes a stator core 51, an insulator 52, and a coil portion 53.

[0087] The stator core 51 surrounds the rotor core 41a from the outer side in the radial direction. The stator core 51 includes a core back portion 51a having a substantially annular shape, and a plurality of teeth portions 51b protruding toward the inner side in the radial direction from an inner circumferential surface of the core back portion 51a. Although not elaborated in the figures, the plurality of teeth portions 51b are disposed at an interval in the circumferential direction. The coil portion 53 is wound around the teeth portions 51b via the insulator 52. The coil portion 53 is formed of a wound coil wire. Although not elaborated in the figures, the coil portion 53 is electrically connected to the control device 56. The control device 56 supplies current to the coil portion 53.

[0088] The shaft 43 has a substantially columnar shape extending in the axial direction. In the present example embodiment, the shaft 43 has a substantially columnar shape that is centered on the rotation axis J and extends in the axial direction. The shaft 43 may be centered on a virtual axis extending in an axial direction different from the rotation axis J, and extend in the axial direction. The shaft 43 extends across the motor accommodation portion 12 and the pump accommodation portion 16. The shaft 43 has an upper side portion disposed in the motor accommodation portion 12. The upper side portion of the shaft 43 passes through the inside of the rotor core 41a in the axial direction. The rotor core 41a is fixed to the outer circumferential surface of the shaft 43. Thus, the rotor 41 is fixed to the shaft 43. Therefore, the shaft 43 is rotatable together with the rotor 41. A portion of the shaft 43 on the center side in the axial direction passes through the inside of the communication hole portion 18c of the housing body portion 11 and the inside of the tubular portion 29 of the metal housing portion 25 in the axial direction. As described above, the tubular portion 29 is between the shaft 43 and the inner circumferential surface of the communication hole portion 18c. The shaft 43 is supported by the tubular portion 29 to be rotatable about the rotation axis J. The shaft 43 has a lower side portion disposed in the pump accommodation portion 16. The lower side portion of the shaft 43 is coupled to the pump 60. Thus, the rotational torque of the rotor 41 is transmitted to the pump 60 through the shaft 43.

[0089] The control device 56 generates current to be supplied to the coil portion 53 and supplies the current to the coil portion 53. Thus, the control device 56 controls the operation of the electric oil pump 1. The control device 56 includes a circuit board 57.

[0090] The circuit board 57 has a plate shape spreading in a direction orthogonal to the axial direction. The circuit board 57 is held by the plurality of board holding portions 12h of the housing body portion 11. A plurality of electronic components are mounted on the circuit board57. The plurality of electronic components include a plurality of power semiconductor elements such as an insulated gate bipolar transistor (IGBT) and a metal-oxide-semiconductor field-effect transistor (MOSFET), a plurality of capacitors, a plurality of resistance elements, and the like. The circuit board 57 is electrically connected to each of an external power supply (not illustrated) and the coil portion 53. The circuit board 57 generates current having a predetermined waveform from current supplied by an external power supply, and supplies the generated current to the coil portion 53. When the coil portion 53 is supplied with current, each of the rotor 41 and the shaft 43 rotates about the rotation axis J.

[0091] The pump 60 is accommodated in the housing body portion 11. More specifically, the pump 60 is accommodated in the pump accommodation portion 16. The pump 60 is accommodated in the metal housing portion 25. As described above, the circumferential wall portion 26 surrounds the pump 60 from the outer side in the radial direction. The top wall portion 27 faces the pump 60 in the axial direction. The pump 60 is coupled to the end portion of the shaft 43 on the lower side, that is, the one side (+Z side) in the axial direction. The pump 60 is driven by the power from the motor 40 to suck oil from the outside of the electric oil pump 1, and compresses the sucked oil to discharge the oil to the outside of the electric oil pump 1. The pump 60 is driven by the power from the motor 40 to pump the oil. The pump 60 of the present example embodiment is a trochoid pump. That is, the electric oil pump 1 of the present example embodiment is a positive displacement electric oil pump. In the present example embodiment, the pump 60 is made of metal. The pump 60 includes the inner rotor 61 and the outer rotor 62.

[0092] The inner rotor 61 extends in the axial direction, and has an annular shape as viewed in the axial direction. A portion of the shaft 43 on the lower side is inserted in the inner rotor 61. The shaft 43 is fixed to the inner circumferential surface of the inner rotor 61. Therefore, the inner rotor 61 is coupled to the lower side, that is, the one side (+Z side) in the axial direction of the shaft 43. The power from the rotor 41 is transmitted to the inner rotor 61. Thus, the inner rotor 61 can be rotated about the rotation axis J. In addition, the inner circumferential surface of the inner rotor 61 and the shaft 43 do not need to be firmly fixed to each other. The inner circumferential surface (inner diameter) of the inner rotor 61 and the outer diameter of the shaft 43 can each have a flat surface portion formed by machining. The inner circumferential surface (inner diameter) of the inner rotor 61 and the shaft 43 may be inserted by clearance fit such that the flat surface portion of the inner circumferential surface (inner diameter) of the inner rotor 61 and the flat surface portion of the outer diameter of the shaft 43 face each other. With this configuration, it is possible to transmit the power of the rotor 41 to the inner rotor 61 while improving the assembly workability of the inner rotor 61 and the shaft 43. Further, by using a retaining ring, it is possible to suppress relative positional deviation between the inner rotor 61 and the shaft 43 in the axial direction.

[0093] The outer rotor 62 is provided more on the outer side in the radial direction than the inner rotor 61. The outer rotor 62 has an annular shape to surround the inner rotor 61 from the outer side in the radial direction. A gap is provided between the outer rotor 62 and the circumferential wall portion 26. The outer circumferential surface of the outer rotor 62 may partially come into contact with the inner circumferential surface of the circumferential wall portion 26. During operation of the electric oil pump 1, oil is interposed between the outer rotor 62 and the circumferential wall portion 26.

[0094] Each of the inner rotor 61 and the outer rotor 62 has a trochoid tooth profile (not illustrated) as illustrated in FIG. 9. The inner rotor 61 has a plurality of external teeth 61a protruding toward the outer side in the radial direction. The outer rotor 62 has a plurality of internal teeth 62a that protrude toward the inner side in the radial direction and mesh with the external teeth 61a. When the inner rotor 61 rotates integrally with the shaft 43 about the rotation axis J, the outer rotor 62 eccentrically rotates about the rotation axis J while sliding on the inner circumferential surface of the circumferential wall portion 26.

[0095] The inside of the second suction-side groove portion 33a and the inside of the first suction-side groove portion 19a are connected in the axial direction via a gap G between the inner rotor 61 and the outer rotor 62, the first suction-side through hole 28a, and the second suction-side through hole 38a as illustrated in FIG. 3. In the following description, the internal space of the second suction-side groove portion 33a, the gap G, and the first suction-side groove portion 19a connected to each other are referred to as a suction chamber A1. The suction chamber A1 is connected to the suction port 32a.

[0096] The inside of the second discharge-side groove portion 33c and the inside of the first discharge-side groove portion 19c are connected in the axial direction via the gap G between the inner rotor 61 and the outer rotor 62, the first discharge-side through hole 28c, and the second discharge-side through hole 38c. In the following description, the internal space of the second discharge-side groove portion 33c, the gap G, and the internal space of the first discharge-side groove portion 19c connected to each other, are referred to as a compression chamber A2. The compression chamber A2 is connected to the discharge port 32c via the discharge hole portion 32b.

[0097] During operation of the electric oil pump 1, the gap G between the inner rotor 61 and the outer rotor 62 moves around the rotation axis J due to rotation of the inner rotor 61 and the outer rotor 62. Therefore, when the pressure in the suction chamber A1 drops, the oil flows into the suction chamber A1 through the suction port 32a as indicated by an arrow F1 in FIG. 3. More specifically, although not elaborated in the figures, the oil that has flowed into the second suction-side groove portion 33a through the suction port 32a flows through the inside of the second suction-side groove portion 33a in the circumferential direction and is sucked into the gap G via the second suction-side through hole 38a. The oil sucked into the gap G partially flows into the first suction-side groove portion 19a through the first suction-side through hole 28a. The oil that has flowed into the first suction-side groove portion 19a flows through the inside of the first suction-side groove portion 19a in the circumferential direction and is sucked into the gap G again.

[0098] When the gap G moves in the circumferential direction due to the rotation of the inner rotor 61 and the outer rotor 62, the oil moves from the suction chamber A1 to the compression chamber A2 as indicated by an arrow F2 in FIG. 3. Although not elaborated in the figures, the oil sucked into the gap G partially flows into the first discharge-side groove portion 19c through the first discharge-side through hole 28c. As described above, the oil sucked from the suction port 32a partially flows into the first suction-side groove portion 19a through the first suction-side through hole 28a. Thus, the oil pumped by the pump 60 passes through the first through hole 28. The oil that has flowed into the first discharge-side groove portion 19c flows through the first discharge-side groove portion 19c in the circumferential direction and is sucked into the gap G again. As described above, the oil that has flowed into the first suction-side groove portion 19a flows in the circumferential direction inside the first suction-side groove portion 19a. Thus, the oil pumped by the pump 60 flows in the first groove portion 19. The oil sucked into the gap G flows into the second discharge-side groove portion 33c via the second discharge-side through hole 38c. The oil that has flowed into the second discharge-side groove portion 33c flows in the circumferential direction inside the second discharge-side groove portion 33c. Thus, when the pressure of the oil in the compression chamber A2 rises, as indicated by an arrow F3 in FIG. 3, the oil in the compression chamber A2 is pumped to the outside of the electric oil pump 1 through the discharge hole portion 32b and the discharge port 32c. Thus, the electric oil pump 1 supplies oil to an attached body not illustrated.

[0099] As described above, in the present example embodiment, in the suction chamber A1, the oil flows into each of the first suction-side groove portion 19a and the second suction-side groove portion 33a. Therefore, a force toward the lower side received from the oil inside the first suction-side groove portion 19a and a force toward the upper side received from the oil inside the second suction-side groove portion 33a are applied to the pump 60. In the present example embodiment, in the compression chamber A2, the oil flows into each of the first discharge-side groove portion 19c and the second discharge-side groove portion 33c. Therefore, a force toward the lower side received from the oil inside the first discharge-side groove portion 19c and a force toward the upper side received from the oil inside the second discharge-side groove portion 33c are applied to the pump 60. Therefore, a force toward the lower side received from the oil inside the first groove portion 19 and a force toward the upper side received from the oil inside the second groove portion 33 are applied to the pump 60. Therefore, in the present example embodiment, the pump 60 can be rotated in a state where the force of the oil is applied to the pump 60 from both sides in the axial direction. Therefore, while the electric oil pump 1 is operating, vibration of the inner rotor 61 and the outer rotor 62 can be suppressed.

[0100] As described above, the inside of the tubular portion 29 is connected to the inside of the pump accommodation portion 16 through the first notch portion29a. As described above, the inside of the tubular portion 29 is connected to the inside of the first discharge-side groove portion 19c and the inside of the accommodation recess portion 17 through the second notch portion 27a, the communication groove portion 18g, and the first notch portion 29a. Therefore, as indicated by an arrow F4 in FIG. 3, the oil sucked into the gap G and the oil inside the first discharge-side groove portion 19c partially flow into the tubular portion 29 and flow toward the upper side between the shaft 43 and the tubular portion 29. Therefore, oil can be supplied to a section between the shaft 43 and the tubular portion 29. Accordingly, the shaft 43 and the tubular portion 29 can be suitably lubricated by the oil, and thus the frictional force between the shaft 43 and the tubular portion 29 can be reduced. As indicated by the arrow F4 in FIG. 3, the oil flowing toward the upper side between the shaft 43 and the tubular portion 29 flows into the motor accommodation portion 12. Therefore, the oil can be supplied to the inside of the motor accommodation portion 12.

[0101] As described above, in the present example embodiment, each of the second notch portion 27a and the communication groove portion 18g is connected to the first discharge-side groove portion 19c. As described above, the pressure of the oil in the compression chamber A2 is high. Accordingly, in the present example embodiment, the oil can flow into the tubular portion 29 from the first discharge-side groove portion 19c at a high flow rate. Therefore, the shaft 43 and the tubular portion 29 can be suitably lubricated by the oil, and the amount of oil flowing into the motor accommodation portion 12 can be increased. Each of the second notch portion 27a and the communication groove portion 18g may be connected to the first suction-side groove portion 19a. Also in this case, the oil can flow into the tubular portion 29 from the first suction-side groove portion 19a, so that the shaft 43 and the tubular portion 29 can be lubricated by the oil, and the oil can be supplied to the motor accommodation portion 12. That is, with the second notch portion 27a and the communication groove portion 18g each connected to the first groove portion 19, the shaft 43 and the tubular portion 29 can be lubricated with the oil, and the oil can be supplied to the motor accommodation portion 12.

[0102] The rotation of the rotor 41 causes the oil that has flowed into the motor accommodation portion 12 to circulate inside the motor accommodation portion 12, and cool each of the motor 40 and the control device 56. As a result, excessive rise in temperature of each of the motor 40 and the control device 56 can be suppressed, whereby the motor 40 and the control device 56 can operate with improved stability.

[0103] As described above, the outflow hole 18e connects the inside of the motor accommodation portion 12 and the inside of the first suction-side groove portion 19a. Therefore, when the pressure in the suction chamber A1 drops while the electric oil pump 1 is operating, the oil circulating in the motor accommodation portion 12 partially flows into the first suction-side groove portion 19a through the outflow hole 18e as indicated by an arrow F5 in FIG. 3. The oil that has flowed into the first suction-side groove portion 19a is pumped to the outside of the electric oil pump 1 through the discharge port 32c, together with the oil that has flowed into the suction chamber A1 through the suction port 32a.

[0104] The electric oil pump 1 according to the present example embodiment includes: the shaft 43 extending in the axial direction; the motor 40 including the rotor 41 that is rotatably fixed to the shaft 43, and the stator 50 facing the rotor 41 with a gap in the radial direction; the pump 60 driven to pump oil by power of the motor 40; and the housing 10 accommodating the motor 40 and the pump 60, wherein the pump 60 includes the inner rotor 61 coupled to the shaft 43 on the lower side, that is, the one side (+Z side) in the axial direction and having the external teeth 61a, and the outer rotor 62 surrounding the inner rotor 61 from an outer side in the radial direction and having the internal teeth 62a meshing with the external teeth 61a, the housing 10 includes the housing body portion 11 made of resin and the metal housing portion 25 made of metal, the housing body portion 11 includes the accommodation recess portion 17 that is recessed from the end portion on the lower side toward the upper side, that is, the other side (−Z side) in the axial direction and accommodates the pump 60, and the stator holding portion 12g that holds the stator 50, the accommodation recess portion 17 includes the recess portion inner circumferential surface 17a surrounding the pump 60 from the outer side in the radial direction, the metal housing portion 25 is at least partially embedded in the housing body portion 11, and the metal housing portion 25 includes the cylindrical circumferential wall portion 26 disposed between the pump 60 and the recess portion inner circumferential surface 17a in the radial direction. In the present example embodiment, since the housing body portion 11 is made of resin, the volume of the metal material forming the housing 10 can be reduced as compared with the case where the housing body portion 11 is made of metal. Further, since the housing body portion 11 is made of resin, the manufacturing cost of the housing 10 can be suitably reduced. Further, in the present example embodiment, the housing body portion 11 holds each of the stator 50 and the metal housing portion 25, and the metal housing portion 25 is at least partially embedded in the housing body portion 11. Therefore, in the present example embodiment, even when the temperature of the electric oil pump 1 varies, it is possible to more suitably suppress a decrease in the positional accuracy between the center axis of the stator 50 and the center axis of the metal housing portion 25. Accordingly, even when the temperature of the electric oil pump 1 varies, it is possible to suitably suppress a decrease in the positional accuracy between the center axis of the motor 40 and the center axis of the pump 60. Therefore, the loss of the driving force transmitted from the motor 40 to the pump 60 via the shaft 43 can be suitably reduced. Therefore, it is possible to suppress a decrease in the flow rate of the oil discharged from the pump 60 while reducing the weight of the electric oil pump 1.

[0105] In a case where the housing body portion 11 is made of resin, the thermal expansion of the housing body portion 11 in response to a temperature rise of the electric oil pump 1 is larger than that of the pump 60. Therefore, when the temperature of the electric oil pump 1 rises, the gap between the recess portion inner circumferential surface 17a and the pump 60 in the radial direction increases. In view of this, in the present example embodiment, as described above, the circumferential wall portion 26 made of metal is between the pump 60 and the recess portion inner circumferential surface 17a, so that the increase in gap can be suppressed between the pump 60 and the circumferential wall portion 26 in the radial direction even when the temperature of the electric oil pump 1 rises. Therefore, it is possible to suppress leakage of oil into a section between the pump 60 and the circumferential wall portion 26. Therefore, it is possible to suppress a decrease in the flow rate of the oil discharged from the pump 60 while reducing the weight of the electric oil pump 1.

[0106] In the present example embodiment, as described above, since the housing body portion 11 is made of resin, the size of the housing body portion 11 tends to vary greatly due to shrinkage after molding. Therefore, in order to avoid interference between the inner surface of the accommodation recess portion 17 and the pump 60, it is necessary to design the accommodation recess portion 17 and the pump 60 to achieve a large difference in size therebetween. Therefore, the gap in the radial direction between the pump 60 and the recess portion inner circumferential surface 17a tends to be large. Therefore, when the housing 10 does not include the metal housing portion 25, the amount of oil leaking into a section between the pump 60 and the recess portion inner circumferential surface 17a is likely to be large, and thus the flow rate of oil discharged from the pump 60 is likely to be low. In view of this, in the present example embodiment, as described above, the circumferential wall portion 26 made of metal is between the pump 60 and the recess portion inner circumferential surface 17a in the radial direction, so that leakage of oil into a section between the pump 60 and the circumferential wall portion 26 can be suppressed. Therefore, it is possible to suitably suppress a decrease in the flow rate of the oil discharged from the pump 60 while reducing the weight of the electric oil pump 1.

[0107] In the present example embodiment, as described above, the circumferential wall portion 26 made of metal is between the pump 60 and the recess portion inner circumferential surface 17a in the radial direction, and thus, a direct contact between the outer rotor 62 and the recess portion inner circumferential surface 17a made of resin can be suppressed. Therefore, while the electric oil pump 1 is operating, it is possible to suppress the wearing of the recess portion inner circumferential surface 17a due to friction with the outer rotor 62. Therefore, the durability of the electric oil pump 1 can be improved.

[0108] According to the present example embodiment, the accommodation recess portion 17 has the top surface 17e that is located more on the upper side, that is, the other side (−Z side) in the axial direction than the pump 60, and faces the pump 60 in the axial direction, and the metal housing portion 25 has the top wall portion 27 that is between the pump 60 and the top surface 17e in the axial direction. Therefore, it is possible to suppress the direct contact between each of the inner rotor 61 and the outer rotor 62 and the top surface 17e made of resin. Therefore, while the electric oil pump 1 is operating, wearing of the top surface 17e due to friction with the inner rotor 61 and the outer rotor 62 can be suppressed. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0109] According to the present example embodiment, the end portion of the circumferential wall portion 26 on the upper side, that is, the other side (−Z side) in the axial direction is connected to the end portion of the top wall portion 27 on the outer side in the radial direction over the entire circumference in the circumferential direction. Therefore, it is possible to suitably suppress the leakage of the oil to the outside of the metal housing portion 25 from between the circumferential wall portion 26 and the top wall portion 27. Therefore, it is possible to suppress the leakage of the oil into a section between the circumferential wall portion 26 and the recess portion inner circumferential surface 17a, and thus it is possible to more suitably suppress a decrease in the flow rate of the oil discharged from the pump 60.

[0110] According to the present example embodiment, the top wall portion 27 is provided with the first through hole 28 extending through the top wall portion 27 in the axial direction, and the surface of the top wall portion 27 facing the lower side, that is, the one side (+Z side) in the axial direction is located more on the lower side than the top surface 17e. Therefore, it is possible to suppress the direct contact between each of the inner rotor 61 and the outer rotor 62 and the top surface 17e made of resin, via the first through hole 28. Therefore, while the electric oil pump 1 is operating, wearing of the top surface 17e due to friction with the inner rotor 61 and the outer rotor 62 can be more suitably suppressed. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0111] According to the present example embodiment, the top wall portion 27 is provided with the first through hole 28 extending through the top wall portion 27 in the axial direction, the top surface 17e is provided with the first groove portion 19 that is recessed toward the upper side, that is, the other side (−Z side) in the axial direction and extends in a circumferential direction, and the first through hole 28 at least partially overlaps the first groove portion 19 as viewed in the axial direction. Accordingly, the inside of the first groove portion 19 is connected to the inside of the accommodation recess portion 17 through the first through hole 28 as described above. Therefore, while the electric oil pump 1 is operating, the oil that has flowed into the pump 60 through the suction port 32a partially flows in the circumferential direction inside the first groove portion 19 and is sucked into the gap G between the inner rotor 61 and the outer rotor 62. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be increased by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of the oil discharged from the pump 60 can be suitably increased.

[0112] According to the present example embodiment, the housing body portion 11 includes the motor accommodation portion 12 that accommodates the motor 40, the communication hole portion 18c through which the shaft 43 passes in the axial direction, the communication hole portion 18c connecting an inside of the motor accommodation portion 12 and an inside of the accommodation recess portion 17, the top wall portion 27 has an annular plate shape expanding in the radial direction, the metal housing portion 25 includes the tubular portion29 having a tubular shape and extending from an inner edge of the top wall portion 27 in the radial direction toward the upper side, that is, the other side (−Z side) in the axial direction, and the tubular portion 29 is between the shaft 43 and an inner circumferential surface of the communication hole portion 18c in the radial direction. Therefore, as described above, it is possible to suppress the direct contact between the shaft 43 and the communication hole portion 18c made of resin. Therefore, while the electric oil pump 1 is operating, wearing of the communication hole portion 18c due to friction with the shaft 43 can be suppressed. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0113] According to the present example embodiment, the housing 10 includes the pump cover 31 made of resin and closing the accommodation recess portion 17 from the lower side, that is, the one side (+Z side) in the axial direction, and the bottom plate portion 37 that is made of metal, that is fixed to the surface of the pump cover 31 facing upper side, that is, the other side (−Z side) in the axial direction, and that faces the pump 60 in the axial direction. Therefore, the volume of the metal material forming the housing 10 can be more suitably reduced as compared with the case where the pump cover 31 is made of metal. Therefore, the manufacturing cost of the housing 10 can be reduced more suitably, and the weight of the housing 10 can be reduced more suitably. Therefore, the manufacturing cost of the electric oil pump 1 can be reduced more suitably, and the weight of the electric oil pump 1 can be reduced more suitably.

[0114] In the present example embodiment, as described above, the bottom plate portion 37 can suppress direct contact between each of the inner rotor 61 and the outer rotor 62 and the pump cover 31 made of resin. Therefore, while the electric oil pump 1 is operating, it is possible to suppress the wearing of the pump cover 31 due to the friction with the inner rotor 61 and the outer rotor 62. Therefore, the durability of the electric oil pump 1 can be more suitably improved while reducing the weight of the electric oil pump 1.

[0115] According to the present example embodiment, the end portion of the bottom plate portion 37 on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion 26. Therefore, it is easy to suppress an increase in the gap between the bottom plate portion 37 and the circumferential wall portion 26, whereby suppression of direct contact between the pump 60 and the pump cover 31 made of resin via the gap between the bottom plate portion 37 and the circumferential wall portion 26 can be easily achieved. Therefore, while the electric oil pump 1 is operating, it is possible to more suitably suppress the wearing of the pump cover 31 due to the friction with the inner rotor 61 and the outer rotor 62. Therefore, the durability of the electric oil pump 1 can be more suitably improved.

[0116] According to the present example embodiment, the end portion of the bottom plate portion 37 on the outer side in the radial direction comes into contact with the surface of the circumferential wall portion 26 facing the lower side, that is, the one side (+Z side) in the axial direction. The bottom plate portion 37 is more easily brought into contact with the circumferential wall portion 26 than in a case where the end portion of the bottom plate portion 37 on the outer side in the radial direction is located more on the inner side in the radial direction than the circumferential wall portion 26. In the present example embodiment, the end portion of the bottom plate portion 37 on the outer side in the radial direction comes into contact with the surface of the circumferential wall portion 26 facing the lower side, and thus the bottom plate portion 37 and the circumferential wall portion 26 can be in firm contact with each other. Since the bottom plate portion 37 and the circumferential wall portion 26 can be firmly in contact with each other, it is possible to suitably suppress leakage of the oil inside the metal housing portion 25 from between the bottom plate portion 37 and the circumferential wall portion 26. Therefore, it is possible to more suitably suppress a decrease in the flow rate of the oil discharged from the pump 60. Therefore, the volumetric efficiency of the pump 60 can be improved, and the pump efficiency can be improved.

[0117] According to the present example embodiment, a surface of the pump cover 31 facing the upper side, that is, the other side (−Z side) in the axial direction is provided with the second groove portion 33 that is recessed toward the lower side, that is, the one side (+Z side) in the axial direction and extends in the circumferential direction, the bottom plate portion 37 is provided with the second through hole 38 extending through the bottom plate portion 37 in the axial direction, and the second through hole 38 at least partially overlaps the second groove portion 33 as viewed in the axial direction. Accordingly, the inside of the second groove portion 33 is connected to the inside of the accommodation recess portion 17 through the second through hole 38 as described above. Therefore, while the electric oil pump 1 is operating, the oil that has flowed into the pump 60 through the suction port 32a partially flows in the circumferential direction inside the second groove portion 33 and is sucked into the gap G between the inner rotor 61 and the outer rotor 62, through the second through hole 38. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be more suitably increased by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of the oil discharged from the pump 60 can be more suitably increased.

[0118] According to the present example embodiment, as described above, the force toward the lower side received from the oil inside the first groove portion 19 and the force toward the upper side received from the oil inside the second groove portion 33 are applied to the pump 60, and thus, it is possible to suppress vibration of the inner rotor 61 and the outer rotor 62 while the electric oil pump 1 is operating. Therefore, the rotation of the inner rotor 61 and the outer rotor 62 can be stabilized, and thus, a decrease in the discharge amount of oil discharged from the pump 60 and variation in the discharge pressure of oil can be suitably suppressed.

[0119] FIG. 10 is a perspective view illustrating an electric oil pump 201 of the present example embodiment. In the following description, components similar to those of the first example embodiment described above are denoted by the same reference signs, and description thereof will be omitted. As illustrated in FIG. 11, the electric oil pump 201 of the present example embodiment is used, for example, for supplying oil to an attached body 5. The attached body 5 may be an automatic transmission, a drive device that drives an axle of a vehicle, or an electric flight vehicle such as an electric vertical takeoff and landing (EVTOL). The electric oil pump 201 includes a housing 210, the motor 40, a shaft 243, the control device 56, the pump 60, a first sealing member 91, and a second sealing member 92.

[0120] The housing 210 has a substantially cylindrical shape extending in the axial direction. The housing 210 accommodates each of the motor 40, the shaft 243, the control device 56, and the pump 60. The housing 210 includes a housing body portion 211, a lid portion 221, a metal housing portion 225, a pump cover 231, and a bottom plate portion 237. In the present example embodiment, the housing body portion 211, the lid portion 221, and the metal housing portion 225, the pump cover 231, and the bottom plate portion 237 are separate members.

[0121] The housing body portion 211 has a tubular shape extending in the axial direction. More specifically, the housing body portion 211 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The housing body portion 211 accommodates each of the motor 40, the shaft 243, and the pump 60. In the present example embodiment, the housing body portion 211 is made of resin. The housing body portion 211 may be made of another material such as a metal material. As a material forming the housing body portion 211, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, or the like can be used. In the present example embodiment, the housing body portion 211 is molded by insert molding using the metal housing portion 225 and a stator 50 of the motor 40 as inserts. The metal housing portion 225 is at least partially embedded in the housing body portion 211. Thus, the metal housing portion 225 is fixed to the housing body portion 211. The stator 50 is embedded in the housing body portion 211. The housing body portion 211 includes a motor accommodation portion 212, a pump accommodation portion 216, and a plurality of ribs 220.

[0122] The motor accommodation portion 212 is an upper side portion of the housing body portion 211. The motor accommodation portion 212 is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the pump accommodation portion 216. The motor accommodation portion 212 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The motor accommodation portion 212 is open on the upper side. The motor accommodation portion 212 accommodates the motor 40. In the present example embodiment, the outer diameter (outer shape) of the motor accommodation portion 212 is larger than the outer diameter (outer shape) of the pump accommodation portion 216. The outer diameter of the motor accommodation portion 212 may be smaller than the outer diameter of the pump accommodation portion 216. The motor accommodation portion 212 includes a first side wall portion 212a, a third welded portion 212d, the stator holding portion 12g, a step portion 212k, and the attachment portion 14. That is, the housing body portion 211 includes the stator holding portion 12g and the third welded portion 212d. The stator 50 is embedded in the stator holding portion 12g. Thus, the stator holding portion 12g holds the stator 50. The configurations and the like of the stator holding portion 12g and the attachment portion 14 of the present example embodiment are similar to the configurations and the like of the stator holding portion 12g and the attachment portion 14 of the first example embodiment described above.

[0123] The first side wall portion 212a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The first side wall portion 212a surrounds an upper side portion of each of the motor 40 and the shaft 243 from the outer side in the radial direction. The first side wall portion 212a is provided with the first annular groove portion 12c. The configuration and the like of the first annular groove portion 12c of the present example embodiment are similar to the configuration and the like of the first annular groove portion 12c of the first example embodiment described above. The first sealing member 91 is fitted in the first annular groove portion 12c. In the present example embodiment, the first sealing member 91 is an O-ring. The first sealing member 91 has an annular shape surrounding the housing body portion 211 from the outer side in the radial direction. The first sealing member 91 is attached to the housing body portion 211. As illustrated in FIG. 10, the first sealing member 91 is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the plurality of ribs 220.

[0124] As illustrated in FIG. 11, the third welded portion 212d has an annular shape protruding toward the upper side from the first side wall portion 212a. The third welded portion 212d has a substantially annular shape centered on the rotation axis J. The third welded portion 212d faces the lid portion 221 in the axial direction. The third welded portion 212d is provided with a first projection portion 212e. The first projection portion 212e is a projection protruding toward the upper side from the surface of the third welded portion 212d facing the upper side. The first projection portion 212e extends over the entire circumference in the circumferential direction.

[0125] The step portion 212k protrudes toward the lower side from the first side wall portion 212a and extends over the entire circumference in the circumferential direction. The step portion 212k has a substantially annular shape centered on the rotation axis J. The step portion 212k is connected to the pump accommodation portion 216 in the axial direction. The outer diameter of the step portion 212k is smaller than the outer diameter of the first side wall portion 212a.

[0126] The pump accommodation portion 216 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. As illustrated in FIG. 12, the surface of the pump accommodation portion 216 facing the lower side is a lower end portion of the housing body portion 211. The pump accommodation portion 216 has an opening portion 217c that opens on the lower side, that is, the one side (+Z side) in the axial direction. The pump accommodation portion 216 accommodates the pump 60. The pump accommodation portion 216 surrounds the pump 60 from the outer side in the radial direction. The pump accommodation portion 216 includes a second side wall portion 216a, a first welded portion 216b, and an annular wall portion 218. That is, the housing body portion 211 includes the first welded portion 216b. The pump accommodation portion 216 is provided with an accommodation recess portion 217. Thus, the housing body portion 211 includes the accommodation recess portion 217.

[0127] The second side wall portion 216a has a substantially cylindrical shape that is centered on the rotation axis J and extends in the axial direction. The second side wall portion 216a surrounds a lower side portion of each of the pump 60 and the shaft 243 from the outer side in the radial direction. The second side wall portion 216a is connected to the step portion 212k in the axial direction. The outer diameter of the step portion 212k is larger than the outer diameter of the second side wall portion 216a.

[0128] The first welded portion 216b is disposed on the lower side of the second side wall portion 216a. The first welded portion 216b is connected to the second side wall portion 216a in the axial direction. The first welded portion 216b is a lower side end portion of the housing body portion 211. Therefore, the housing body portion 211 has the first welded portion 216b at the end portion in the axial direction. The first welded portion 216b protrudes more on the outer side in the radial direction than the second side wall portion 216a. As viewed in the axial direction, the first welded portion 216b has an annular shape centered on the rotation axis J. The first welded portion 216b faces the pump cover 231 in the axial direction. As illustrated in FIG. 15, the first welded portion 216b includes a first welded protrusion portion 216c. The first welded protrusion portion 216c is a projection that protrudes toward the lower side, that is, the one side (+Z side) in the axial direction from the surface of the first welded portion 216b facing the lower side. The first welded protrusion portion 216c extends over the entire circumference in the circumferential direction. As viewed in the axial direction, the first welded protrusion portion 216c has an annular shape centered on the rotation axis J. The size of the first welded protrusion portion 216c in the radial direction is larger than the size of the first welded protrusion portion 216c in the axial direction.

[0129] As illustrated in FIG. 12, the accommodation recess portion 217 is a hole that is recessed toward the upper side from the surface of the pump accommodation portion 216 facing the lower side. That is, the accommodation recess portion 217 is a hole that is recessed from the lower side of the housing body portion 211, that is, the end portion on the one side (+Z side) in the axial direction toward the upper side, that is, the other side (−Z side) in the axial direction. The accommodation recess portion 217 accommodates the pump 60. The accommodation recess portion 217 includes a recess portion inner circumferential surface 217a and a top surface 217e.

[0130] The recess portion inner circumferential surface 217a is a surface, of the inner surface of the accommodation recess portion 217, facing the inner side in the radial direction. As viewed in the axial direction, the recess portion inner circumferential surface 217a has a substantially circular shape centered on the rotation axis J. The recess portion inner circumferential surface 217a surrounds the pump 60 from the outer side in the radial direction. The opening portion 217c is the lower end of the recess portion inner circumferential surface 217a.

[0131] The top surface 217e is a surface, of the inner surface of the accommodation recess portion 217, facing the lower side. The top surface 217e is a surface, of the annular wall portion 218, facing the lower side. The top surface 217e faces the pump 60 in the axial direction. Other configurations and the like of the accommodation recess portion 217 of the present example embodiment are similar to other configurations and the like of the accommodation recess portion 17 of the first example embodiment described above.

[0132] The annular wall portion 218 has a substantially annular shape centered on the rotation axis J. The end portion of the annular wall portion 218 on the outer side in the radial direction is connected to the surface of the step portion 212k facing the inner side in the radial direction, over the entire circumference in the circumferential direction. The annular wall portion 218 is provided more on the lower side than the motor 40 and more on the upper side than the pump 60. The annular wall portion 218 is provided with an inner tubular portion 218a, a communication hole portion 218c, and an outflow hole 218e. Therefore, the housing body portion 211 includes the communication hole portion 218c.

[0133] The inner tubular portion 218a protrudes toward the upper side from the inner edge of the annular wall portion 218 in the radial direction. The inner tubular portion 218a has a substantially cylindrical shape that is centered on the rotation axis J. The inner circumferential surface of the inner tubular portion 218a is connected to the inner circumferential surface of the annular wall portion 218 in the axial direction.

[0134] The communication hole portion 218c is a hole extending through each of the annular wall portion 218 and the inner tubular portion 218a in the axial direction. The communication hole portion 218c is formed by the inner circumferential surface of the annular wall portion 218 and the inner circumferential surface of the inner tubular portion 218a. As viewed in the axial direction, the communication hole portion 218c has a substantially circular shape centered on the rotation axis J. The communication hole portion 218c connects the inside of the motor accommodation portion 212 and the inside of the accommodation recess portion 217. The shaft 243 passes through the inside of the communication hole portion 218c in the axial direction. The outflow hole 218e is a hole extending through the annular wall portion 218 in the axial direction. The outflow hole 218e is provided in a portion on the outer side of the annular wall portion 218 in the radial direction.

[0135] As illustrated in FIG. 10, the ribs 220 are provided on the outer circumferential surface of the second side wall portion 216a, that is, a surface facing the outer side of the pump accommodation portion 216 in the radial direction. That is, each rib 220 is provided on the surface of the housing body portion 211 facing the outer side in the radial direction. Therefore, the strength of the housing body portion 211 can be suitably increased by the ribs 220. Each rib 220 has a plate shape protruding toward the outer side in the radial direction from the pump accommodation portion 216. Although not elaborated in the figures, the ribs 220 include the first rib as in the first example embodiment described above. Although not elaborated in the figures, the first rib is fitted to the positioning portion 34a of the pump cover 231, as in the first example embodiment described above. The ribs 220 are spaced apart from each other in the circumferential direction as illustrated in FIG. 13. As illustrated in FIG. 10, each of the ribs 220 extends in the axial direction. As illustrated in FIG. 12, the upper side end portion of each rib 220 is connected to the surface of the first side wall portion 212a facing the lower side, and the lower side end portion of each of the ribs 220 is connected to the first welded portion 216b. That is, each of the ribs 220 connects the lower side of the motor accommodation portion 212 and the first welded portion 216b in the axial direction. Therefore, when the housing body portion 211 is molded, the ribs 220 can suppress warpage of the first welded portion 216b to have a portion more on the outer side in the radial direction located more on the upper side.

[0136] In the present example embodiment, the end portion of each rib 220 on the lower side is connected to the surface of the first welded portion 216b facing the outer side in the radial direction. Thus, in the present example embodiment, when the housing body portion 211 is molded, the ribs 220 can more suitably suppress the warpage, toward the upper side, of the end portion of the first welded portion 216b on the outer side in the radial direction. The lower side end portion of each rib 220 may not be connected to the surface of the first welded portion 216b facing the outer side in the radial direction. The upper side portion of each rib 220 is connected to the outer surface of the step portion 212k. That is, each rib 220 is connected to the step portion 212k.

[0137] As illustrated in FIG. 13, the plurality of ribs 220 include a plurality of first protruding ribs 220e and two second protruding ribs 220g. The number of the second protruding ribs 220g included in the plurality of ribs 220 may be one. As viewed in the axial direction, each of the first protruding ribs 220e protrudes from the second side wall portion 216a in a first direction D1 orthogonal to the axial direction. In the present example embodiment, the plurality of ribs 220 include six first protruding ribs 220e. The number of the first protruding ribs 220e included in the plurality of ribs 220 is not limited to that in the present example embodiment, and may be five or less, or seven or more. A second virtual straight line VL2 illustrated in FIG. 13 is a virtual straight line that extends in a second direction D2 intersecting both the axial direction and the first direction D1 and passes through the rotation axis J, that is, the center of the motor accommodation portion 212. In the present example embodiment, the second direction D2 is orthogonal to both the axial direction and the first direction D1. The second direction D2 may not be orthogonal to at least one of the axial direction and the first direction D1. As viewed in the axial direction, each of the second protruding ribs 220g protrudes from the second side wall portion 216a in the second direction D2. The second protruding ribs 220g face each other in the radial direction with the rotation axis J interposed therebetween. As viewed in the axial direction, each of the second protruding ribs 220g overlaps the second virtual straight line VL2. Therefore, according to the present example embodiment, when the housing body portion 211 is resin-molded, the housing body portion 211 having the plurality of ribs 220 can be molded by using only a pair of molds (slide molds) that move toward the opposite sides in the first direction D1, when a side surface intersecting the axial direction is molded as appropriate. Therefore, the number of molds used to mold the housing body portion 211 can be reduced as compared with a case where the ribs 220 radially protrude toward the outer side in the radial direction. Therefore, it is possible to suppress an increase in the manufacturing cost and the manufacturing steps for the housing body portion 211. Other configurations and the like of the housing body portion 211 of the present example embodiment are similar to other configurations and the like of the housing body portion 11 of the first example embodiment described above.

[0138] As illustrated in FIG. 11, the lid portion 221 has a substantially cylindrical shape that is centered on the rotation axis J and protrudes in the axial direction. The lid portion 221 is open on the lower side. The lid portion 221 is fixed to the upper end of the housing body portion 211. The lid portion 221 closes the upper side opening of the motor accommodation portion 212. The control device 56 is accommodated in the lid portion 221. In the present example embodiment, the lid portion 221 is made of resin. As a material forming the lid portion 221, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, or the like can be used. The lid portion 221 may be made of another material such as a metal material. The lid portion 221 includes the lid circumferential wall portion 22, a fourth welded portion 222a, and the board cover portion 23.

[0139] The fourth welded portion 222a has an annular shape protruding toward the outer side in the radial direction from the lower side end portion of the lid circumferential wall portion 22. As viewed in the axial direction, the fourth welded portion 222a has an annular shape centered on the rotation axis J. The fourth welded portion 222a faces the third welded portion 212d of the housing body portion 211 in the axial direction. The fourth welded portion 222a is provided with the second annular groove portion 22a. The second annular groove portion 22a is a groove that is recessed toward the upper side from the surface of the fourth welded portion 222a facing the lower side and extends over the entire circumference in the circumferential direction. The first projection portion 212e is inserted in the second annular groove portion 22a. Accordingly, the lid portion 221 can be accurately positioned with respect to the housing body portion 211 in the radial direction. In the present example embodiment, the surface of the second annular groove portion 22a facing the lower side and the first projection portion 212e are welded over the entire circumference in the circumferential direction. Thus, the third welded portion 212d and the fourth welded portion 222a are welded to each other. Therefore, in the present example embodiment, the section between the housing body portion 211 and the lid portion 221 can be suitably sealed, and thus the airtightness of the electric oil pump 201 can be suitably improved. Further, since it is not necessary to separately provide a sealing member such as an O-ring for sealing between the housing body portion 211 and the lid portion 221, it is possible to suppress an increase in the number of components of the electric oil pump 201.

[0140] As illustrated in FIG. 12, the pump cover 231 has a tubular shape extending in the axial direction. More specifically, the pump cover 231 has a substantially annular shape centered on the rotation axis J. The pump cover 231 is provided more on lower side in the axial direction than the pump 60. The pump cover 231 is fixed to a lower end of the pump accommodation portion 216. The pump cover 231 covers the pump 60 from the lower side. The pump cover 231 closes the accommodation recess portion 217 from the lower side, that is, from the one side (+Z side) in the axial direction. The pump cover 231 closes the opening portion 217c from the lower side. In the present example embodiment, the pump cover 231 is made of resin. As a material forming the pump cover 231, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, or the like can be used. The pump cover 231 may be made of another material such as a metal material. The pump cover 231 holds the bottom plate portion 237. The pump cover 231 includes a cover body portion 232, a second welded portion 236, and the protruding tubular portion 35. As illustrated in FIG. 14, the pump cover 231 includes cover protrusion portions 232g, 232h, and 232k.

[0141] The cover body portion 232 is an upper side portion of the pump cover 231 as illustrated in FIG. 12. The cover body portion 232 has a substantially annular shape centered on the rotation axis J. The cover body portion 232 is provided with the suction port 32a and the second groove portion 33. As illustrated in FIG. 14, the cover body portion 232 is provided with a protrusion portion 34. Although not elaborated in the figures, as described above, the first rib is fitted to the positioning portion 34a of the protrusion portion 34. As illustrated in FIG. 10, the cover body portion 232 is provided with a discharge port 232c and a plurality of cover ribs 235. Therefore, the pump cover 231 includes each of the discharge port 232c and the plurality of cover ribs 235. As illustrated in FIG. 15, the cover body portion 232 includes a first plate-shaped portion 236b. That is, the pump cover 231 includes the first plate-shaped portion 236b.

[0142] As illustrated in FIG. 10, the discharge port 232c is a hole extending through the cover body portion 232 in the radial direction. The discharge port 232c opens in the radial direction. As illustrated in FIG. 15, the discharge port 232c is connected to the second discharge-side groove portion 33c. The oil compressed in the pump 60 is discharged to the outside of the electric oil pump 201 through the discharge port 232c. As illustrated in FIG. 16, in the present example embodiment, the discharge port 232c is open in the second direction D2. The direction in which the discharge port 232c opens is not particularly limited, and may be the first direction D1 or may be a direction oriented between the second direction D2 and the first direction D1. As illustrated in FIG. 10, the discharge port 232c has a substantially rectangular shape as viewed in the radial direction.

[0143] As illustrated in FIG. 12, the second welded portion 236 has an annular shape protruding toward the outer side from the upper side end portion of the cover body portion 232 in the radial direction. As viewed in the axial direction, the second welded portion 236 has an annular shape surrounding the rotation axis J. The second welded portion 236 is an upper side end portion of the pump cover 231. Therefore, the pump cover 231 has the second welded portion 236 at the end portion in the axial direction. The second welded portion 236 faces the housing body portion 211 in the axial direction. More specifically, the second welded portion 236 faces the first welded portion 216b in the axial direction. As illustrated in FIG. 15, the second welded portion 236 includes a second welded protrusion portion 236a.

[0144] The second welded protrusion portion 236a is a projection protruding toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the second welded portion 236 facing the upper side. The second welded protrusion portion 236a extends over the entire circumference in the circumferential direction. As viewed in the axial direction, the second welded protrusion portion 236a has an annular shape centered on the rotation axis J. A size of the second welded protrusion portion 236a in the radial direction is larger than a size of the second welded protrusion portion 236a in the axial direction. The second welded protrusion portion 236a and the first welded protrusion portion 216c of the housing body portion 211 face each other in the axial direction. In the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a are welded over the entire circumference in the circumferential direction. Thus, the first welded portion 216b and the second welded portion 236 are welded to each other. That is, the pump accommodation portion 216 and the pump cover 231 are joined to each other by welding over the entire circumference in the circumferential direction. The pump cover 231 is fixed to the surface of the first welded portion 216b facing the lower side, that is, the one side (+Z side) in the axial direction. In the present example embodiment, a portion of the second welded portion 236 other than the second welded protrusion portion 236a faces the first welded portion 216b with a gap in the axial direction.

[0145] As illustrated in FIG. 12, the cover protrusion portions 232g, 232h, and 232k are projections that protrude toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the cover body portion 232 facing the upper side. The cover protrusion portions 232g and 232h face the first welded portion 216b in the axial direction with a gap in between. The cover protrusion portion 232k faces the pump 60 in the axial direction with a gap in between. As illustrated in FIG. 14, as viewed in the axial direction, the cover protrusion portion 232g is provided along the edge portions on both sides in the circumferential direction and the edge portion on the inner side in the radial direction of the second suction-side groove portion 33a. As viewed in the axial direction, the cover protrusion portion 232h is provided along edge portions on both sides in the circumferential direction and an edge portion on the inner side in the radial direction of the second discharge-side groove portion 33c. As viewed in the axial direction, the cover protrusion portion 232k has an annular shape surrounding the bottom plate portion 237.

[0146] As illustrated in FIG. 10, the cover ribs 235 are provided on the outer circumferential surface of the cover body portion 232, that is, the outer surface of the pump cover 231. Therefore, the strength of the pump cover 231 can be suitably increased by the cover ribs 235. Each of the cover ribs 235 has a plate shape protruding toward the outer side from the cover body portion 232 in the radial direction. The cover ribs 235 are spaced apart from each other in the circumferential direction as illustrated in FIG. 16. As illustrated in FIG. 10, each cover rib 235 extends in the axial direction. An upper side end portion of each cover rib 235 is connected to the surface of the second welded portion 236 facing the lower side. Therefore, when the pump cover 231 is molded, the cover ribs 235 can suppress the warpage of the second welded portion 236 to have a portion more on the outer side in the radial direction located more on the lower side.

[0147] As illustrated in FIG. 16, as viewed in the axial direction, each cover rib 235 protrudes in the second direction D2 from the cover body portion 232. As described above, in the present example embodiment, the discharge port 232c is open in the second direction D2. Therefore, each cover rib 235 protrudes from the outer surface of the pump cover 231 in a direction in which the discharge port 232c opens. Therefore, according to the present example embodiment, when the pump cover 231 is molded by injection molding, the pump cover 231 having the discharge port 232c and the plurality of cover ribs 235 can be molded by using only a pair of molds (slide molds) that move in the direction in which the discharge port 232c opens, that is, toward the opposite side in the second direction D2. Therefore, the number of molds used to mold the pump cover 231 can be reduced as compared with a case where the cover ribs 235 are configured to protrude toward the outer side in the radial direction. Therefore, it is possible to suppress an increase in the manufacturing cost and the manufacturing steps for the pump cover 231.

[0148] The plurality of cover ribs 235 include a first cover rib 235a and a second cover rib 235c. The first cover rib 235a and the second cover rib 235c are disposed adjacent to each other in the circumferential direction. The first cover rib 235a and the second cover rib 235c are disposed with the discharge port 232c interposed therebetween in the circumferential direction. The first cover rib 235a is provided more on one side (+θ side) in the circumferential direction than the second cover rib 235c. The first cover rib 235a is provided more on one side in the circumferential direction than the discharge port 232c. The first cover rib 235a is disposed in the vicinity of the discharge port 232c. The second cover rib 235c is provided more on the other side (−θ side) in the circumferential direction than the discharge port 232c. The second cover rib 235c is disposed in the vicinity of the discharge port 232c. Therefore, in the present example embodiment, the cover rib 235 is disposed on each of both sides of the discharge port 232c in the circumferential direction.

[0149] As illustrated in FIG. 15, the first plate-shaped portion 236b is disposed on the upper side, that is, the other side (−Z side) in the axial direction of the discharge port 232c. The first plate-shaped portion 236b has a plate shape spreading in a direction orthogonal to the axial direction. The first plate-shaped portion 236b protrudes toward the outer side in the radial direction from the discharge port 232c. As illustrated in FIGS. 10 and 15, in the present example embodiment, the first plate-shaped portion 236b is part of the second welded portion 236 in the circumferential direction. The first plate-shaped portion 236b is a portion of the second welded portion 236 that overlaps the discharge port 232c as viewed in the axial direction. The first plate-shaped portion 236b may be a member different from the second welded portion 236. As illustrated in FIG. 10, the first plate-shaped portion 236b is provided with a recessed portion 236c.

[0150] The recessed portion 236c is provided in the surface of the first plate-shaped portion 236b on the lower side, that is, the one side (+Z side) in the axial direction. The recessed portion 236c is a recess that is recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the first plate-shaped portion 236b facing the lower side. As illustrated in FIG. 15, the recessed portion 236c is connected to the surface of the discharge port 232c facing the lower side. That is, the recessed portion 236c is connected to the inner surface of the discharge port 232c. Accordingly, in the present example embodiment, the discharge port 232c can be provided on the upper side, and thus the length between the pump 60 and the discharge port 232c can be easily shortened.

[0151] The protruding tubular portion 35 includes the fourth annular groove portion 35a and a second plate-shaped portion 235f. Thus, the pump cover 231 includes the second plate-shaped portion 235f. As illustrated in FIG. 12, the fourth annular groove portion 35a is a groove that is recessed toward the inner side in the radial direction from the surface of the protruding tubular portion 35 facing the outer side in the radial direction and extends in the circumferential direction. The fourth annular groove portion 35a extends over the entire circumference in the circumferential direction. The second sealing member 92 is fitted in the fourth annular groove portion 35a. In the present example embodiment, the second sealing member 92 is an O-ring. The second sealing member 92 has an annular shape that surrounds the pump cover 231 from the outer side in the radial direction. The second sealing member 92 is attached to the pump cover 231. As illustrated in FIG. 10, the second sealing member 92 is provided more on the lower side, that is, the one side (+Z side) in the axial direction than the discharge port 232c. Therefore, in the present example embodiment, as illustrated in FIG. 12, each of the discharge port 232c and the plurality of ribs 220 can be disposed in a space surrounded by the housing body portion 211, the pump cover 231, the first sealing member 91, the second sealing member 92, and the attached body 5.

[0152] As illustrated in FIG. 15, the second plate-shaped portion 235f is disposed on the lower side, that is, the one side (+Z side) in the axial direction of the discharge port 232c. The second plate-shaped portion 235f has a plate shape spreading in a direction orthogonal to the axial direction. The second plate-shaped portion 235f protrudes toward the outer side in the radial direction from the discharge port 232c. As illustrated in FIGS. 10 and 15, in the present example embodiment, the second plate-shaped portion 235f is a part, in the circumferential direction, of the protruding tubular portion 35 more on the upper side than the fourth annular groove portion 35a. The second plate-shaped portion 235f is a portion of the protruding tubular portion 35 that is more on the upper side than the fourth annular groove portion 35a and overlaps the discharge port 232c as viewed in the axial direction. The other configurations and the like of the pump cover 231 of the present example embodiment are similar to the other configurations and the like of the pump cover 31 of the first example embodiment described above.

[0153] As illustrated in FIG. 12, the metal housing portion 225 is accommodated in the housing body portion 211. As described above, the metal housing portion 225 is at least partially embedded in the housing body portion 211. The metal housing portion 225 is made of metal. In the present example embodiment, the metal housing portion 225 is made of aluminum. In the present example embodiment, the metal housing portion 225 is formed by casting. As illustrated in FIG. 17, the metal housing portion 225 includes the circumferential wall portion 26, a top wall portion 227, and a tubular portion 229. As illustrated in FIG. 12, the metal housing portion 225 includes a support surface 225a and a recess portion 225c.

[0154] The circumferential wall portion 26 has a substantially cylindrical shape surrounding the rotation axis J. The circumferential wall portion 26 has a portion on the outer side in the radial direction embedded in the second side wall portion 216a. The circumferential wall portion 26 is fixed to the recess portion inner circumferential surface 217a. In the radial direction, the circumferential wall portion 26 is between the pump 60 and the recess portion inner circumferential surface 217a.

[0155] As illustrated in FIG. 17, the top wall portion 227 has a substantially annular plate shape expanding in the radial direction. The top wall portion 227 has a plate shape that expands toward the outer side in the radial direction from the end portion of the tubular portion 229 on the lower side, that is, the one side (+Z side) in the axial direction. The top wall portion 227 surrounds the rotation axis J. An upper side end portion of the circumferential wall portion 26 is connected to the end portion of the top wall portion 227 on the outer side in the radial direction over the entire circumference in the circumferential direction. As illustrated in FIG. 12, in the present example embodiment, the size of the top wall portion 227 in the axial direction is larger than the size of the circumferential wall portion 26 in the radial direction. An upper side portion of the top wall portion 227 is embedded in the annular wall portion 218. The top wall portion 227 is fixed to the top surface 217e. The top wall portion 227 is between the pump 60 and the top surface 217e in the axial direction. The shaft 243 passes through the inside of the top wall portion 227 in the axial direction. The shaft 243 is supported by the top wall portion 227 to be rotatable about the rotation axis J. As illustrated in FIG. 17, the top wall portion 227 is provided with a top wall through hole 227c and a top wall recess portion 227e. As illustrated in FIG. 12, the top wall portion 227 is provided with a first groove portion 228. As illustrated in FIG. 13, the top wall portion 227 is provided with a communication groove portion 227h.

[0156] The top wall through hole 227c illustrated in FIG. 17 is a hole extending through the top wall portion 227 in the axial direction. The top wall through hole 227c is provided in a portion on the outer side of the top wall portion 227 in the radial direction. As illustrated in FIG. 12, the top wall through hole 227c overlaps the outflow hole 218e as viewed in the axial direction.

[0157] As illustrated in FIG. 17, the top wall recess portion 227e is provided in the surface of the top wall portion 227 facing the outer side in the radial direction. The top wall recess portion 227e is a recess recessed toward the inner side in the radial direction from the surface of the top wall portion 227 facing the outer side in the radial direction. The top wall recess portion 227e is open on the upper side. The top wall recess portion 227e may not be open on the upper side. The top wall portion 227 is provided with a plurality of the top wall recess portions 227e. In the present example embodiment, the top wall portion 227 is provided with three top wall recess portions 227e. The number of top wall recess portions 227e provided in the top wall portion 227 may be two or less, or four or more. The top wall recess portions 227e are provided at a substantially equal interval along the circumferential direction. Although not elaborated in the figures, the housing body portion 211 is partially located inside each of the top wall recess portions 227e. Thus, rotation of the metal housing portion 225 relative to the housing body portion 211 in the circumferential direction can be suppressed.

[0158] As illustrated in FIG. 12, the first groove portion 228 is a groove recessed toward the upper side, that is, the other side (−Z side) in the axial direction from the surface of the top wall portion 227 facing the lower side. The first groove portion 228 is open on the lower side. In the present example embodiment, the top wall portion 227 is provided with two first groove portions 228. The two first groove portions 228 include a first suction-side groove portion 228a and a first discharge-side groove portion 228c.

[0159] As illustrated in FIG. 13, each of the first suction-side groove portion 228a and the first discharge-side groove portion 228c is a substantially arc-shaped groove extending in the circumferential direction, as viewed in the axial direction. That is, the first groove portion 228 is a groove extending in the circumferential direction. The first suction-side groove portion 228a and the first discharge-side groove portion 228c are provided at different positions in the circumferential direction. The first suction-side groove portion 228a and the first discharge-side groove portion 228c face each other in the radial direction. More specifically, the first suction-side groove portion 228a and the first discharge-side groove portion 228c face each other in the radial direction, with the rotation axis J interposed therebetween.

[0160] As illustrated in FIG. 12, the inside of the second suction-side groove portion 33a is connected to the suction port 32a. The second suction-side groove portion 33a overlaps the first suction-side groove portion 228a as viewed in the axial direction. As illustrated in FIGS. 13 and 14, the second suction-side groove portion 33a and the first suction-side groove portion 228a have substantially the same shape as viewed in the axial direction. As illustrated in FIG. 13, the first suction-side groove portion 228a overlaps the top wall through hole 227c and the outflow hole 218e as viewed in the axial direction. The first suction-side groove portion 228a is connected to the inside of the motor accommodation portion 212 through the top wall through hole 227c and the outflow hole 218e.

[0161] As illustrated in FIG. 15, the second discharge-side groove portion 33c is connected to the discharge port 232c. As illustrated in FIG. 12, the second discharge side groove portion 33c overlaps the first discharge-side groove portion 228c as viewed in the axial direction. As illustrated in FIGS. 13 and 14, the second discharge-side groove portion 33c and the first discharge-side groove portion 228c have substantially the same shape as viewed in the axial direction.

[0162] As illustrated in FIG. 12, the communication groove portion 227h is a groove recessed toward the upper side from the surface of the top wall portion 227 facing the lower side. As illustrated in FIG. 13, the communication groove portion 227h extends linearly along the radial direction. The end portion of the communication groove portion 227h on the inner side in the radial direction is open to the inner circumferential surface of the top wall portion 227. The communication groove portion 227h has the end portion, on the outer side in the radial direction, open to the first discharge-side groove portion 228c. Accordingly, the communication groove portion 227h connects the inside of the top wall portion 227 and the first discharge-side groove portion 228c.

[0163] As illustrated in FIG. 17, the tubular portion 229 has a tubular shape extending toward the upper side, that is, the other side (−Z side) in the axial direction from the inner edge of the top wall portion 227 in the radial direction. The tubular portion 229 has a substantially cylindrical shape that is centered on the rotation axis J, and extends in the axial direction. The inner circumferential surface of the tubular portion 229 is connected to the inner circumferential surface of the top wall portion 227 in the axial direction. As illustrated in FIG. 12, the tubular portion 229 is disposed in the communication hole portion 218c. The shaft 243 passes through the inside of the tubular portion 229 in the axial direction. The tubular portion 229 is between the shaft 243 and the inner circumferential surface of the communication hole portion 218c in the radial direction.

[0164] The support surface 225a is formed by the inner circumferential surface of the top wall portion 227 and the inner circumferential surface of the tubular portion 229. As viewed in the axial direction, the support surface 225a has a circular shape centered on the rotation axis J. The shaft 243 is supported by the support surface 225a so as to be rotatable about the rotation axis J. As described above, the tubular portion 229 is between the shaft 243 and the inner circumferential surface of the communication hole portion 218c in the radial direction. Therefore, since a direct contact between the shaft 243 and the communication hole portion 218c made of resin can be suppressed, wearing of the communication hole portion 218c can be suppressed while the electric oil pump 201 is operating.

[0165] The recess portion 225c is a recess that is recessed toward the outer side in the radial direction from the support surface 225a. The recess portion 225c is provided over the entire circumference in the circumferential direction. The recess portion 225c is provided across the top wall portion 227 and the tubular portion 229 in the axial direction. The top wall portion 227 includes a first support portion 227g. The tubular portion 229 includes a second support portion 229c.

[0166] Each of the first support portion 227g and the second support portion 229c is part of the support surface 225a. The first support portion 227g is an intermediate portion of the inner circumferential surface of the top wall portion 227, between the end portion of the recess portion 225c and the end portion of the top wall portion 227 that are on the lower side in the axial direction. The second support portion 229c is an intermediate portion of the inner circumferential surface of the tubular portion 229 between the end portion of the recess portion 225c and the end portion of the tubular portion 229 that are on the upper side in the axial direction. Each of the first support portion 227g and the second support portion 229c supports the shaft 243. Other configurations and the like of the metal housing portion 225 of the present example embodiment are similar to other configurations and the like of the metal housing portion 25 of the first example embodiment described above.

[0167] The bottom plate portion 237 has a substantially disk shape expanding in the radial direction around the rotation axis J. The bottom plate portion 237 is fixed to the surface of the pump cover 231 on the upper side, that is, the other side (−Z side) in the axial direction. The bottom plate portion 237 is provided more on the lower side than the pump 60. The bottom plate portion 237 faces the pump 60 in the axial direction. In the present example embodiment, the bottom plate portion 237 is in contact with the circumferential wall portion 26 of the metal housing portion 225 in the axial direction. The bottom plate portion 237 may face the circumferential wall portion 26 with a gap in between in the axial direction. The end portion of the bottom plate portion 237 on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion 26. The bottom plate portion 237 is provided more on the inner side in the radial direction than the second welded portion 236. That is, the second welded portion 236 is located on the outer side in the radial direction of the bottom plate portion 237. In the present example embodiment, the bottom plate portion 237 is made of metal. As a material forming the bottom plate portion 237, aluminum, stainless steel, or the like can be used.

[0168] As illustrated in FIGS. 12 and 14, in the present example embodiment, the bottom plate portion 237 is fitted to the cover protrusion portions 232g, 232h, and 232k. Thus, the bottom plate portion 237 is fixed to the pump cover 231. The bottom plate portion 237 may be press-fitted or clearance fitted to the cover protrusion portions 232g, 232h, and 232k. The surface of the bottom plate portion 237 facing the upper side is located more on the upper side than the cover protrusion portions 232g, 232h, and 232k. Therefore, since direct contact between the pump 60 and the cover protrusion portions 232g, 232h, and 232k made of resin can be suppressed, it is possible to suppress the wearing of the cover protrusion portions 232g, 232h, and 232k while the electric oil pump 201 is operating. As illustrated in FIG. 14, the bottom plate portion 237 includes a hole portion 237c and the second through hole 38.

[0169] Configurations and the like of the second through hole 38 of the present example embodiment are similar to configurations and the like of the second through hole 38 of the first example embodiment described above. Specifically, the second through hole 38 is a hole extending through the bottom plate portion 237 in the axial direction. In the present example embodiment, the bottom plate portion 237 is provided with a pair of second through holes 38. The pair of second through holes 38 include a second suction-side through hole 38a and a second discharge-side through hole 38c. As viewed in the axial direction, the pair of second through holes 38 are line symmetrical with the line of symmetry being the rotation axis J, that is, a third virtual straight line VL3 passing through the center of the bottom plate portion 237. The second suction-side through hole 38a surrounds the second suction-side groove portion 33a as viewed in the axial direction. Therefore, as illustrated in FIG. 12, the inside of the second suction-side groove portion 33a is connected to the inside of the accommodation recess portion 217 through the second suction-side through hole 38a. As illustrated in FIG. 14, the second discharge-side through hole 38c surrounds the second discharge-side groove portion 33c as viewed in the axial direction. Therefore, as illustrated in FIG. 12, the inside of the second discharge-side groove portion 33c is connected to the inside of the accommodation recess portion 217 through the second discharge-side through hole 38c.

[0170] The hole portion 237c illustrated in FIG. 14 is a hole extending through the bottom plate portion 237 in the axial direction. The hole portion 237c is provided in a portion on the outer side of the bottom plate portion 237 in the radial direction. In the present example embodiment, the hole portion 237c is open on the outer side in the radial direction. The hole portion 237c may not be open on the outer side in the radial direction. As viewed in the axial direction, the hole portion 237c is provided at a position shifted from the third virtual straight line VL3. Therefore, the shape of the bottom plate portion 237 as viewed in the axial direction can be asymmetric with respect to the third virtual straight line VL3.

[0171] As illustrated in FIG. 11, the motor 40 is accommodated in the motor accommodation portion 212. In the axial direction, the motor 40 is provided more on the lower side in the axial direction than the control device 56 and more on the upper side in the axial direction than the pump 60. The motor 40 includes the rotor 41 and the stator 50 that faces the rotor 41 in the radial direction with a gap in between. As illustrated in FIG. 12, in the present example embodiment, the lower side portion of the insulator 52 is embedded in the step portion 212k. Thus, the strength of the step portion 212k can be improved. Configurations and the like of the motor 40 of the present example embodiment are similar to configurations and the like of the motor 40 of the first example embodiment described above.

[0172] As illustrated in FIG. 11, the shaft 243 has a substantially columnar shape that is centered on the rotation axis J and extends in the axial direction. The upper side portion of the shaft 243 passes through the inside of the rotor core 41a in the axial direction. The rotor core 41a is fixed to the outer circumferential surface of the shaft 243. Thus, the rotor 41 is fixed to the shaft 243. As illustrated in FIG. 12, a portion of the shaft 243 on the central side in the axial direction passes through the inside of the tubular portion 229 and the inside of the top wall portion 227 in the axial direction. As described above, the shaft 243 is supported by the support surface 225a so as to be rotatable about the rotation axis J. The lower side portion of the shaft 243 is coupled to the pump 60. Thus, the rotational torque of the rotor 41 is transmitted to the pump 60 through the shaft 243.

[0173] As illustrated in FIG. 11, the control device 56 includes a circuit board 57. The circuit board 57 is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the motor 40. The circuit board 57 supplies current to the motor 40. More specifically, the circuit board 57 supplies a current to the coil portion 53 of the stator 50. The circuit board 57 is accommodated in the lid portion 221. When the coil portion 53 is supplied with current, each of the rotor 41 and the shaft 243 rotates about the rotation axis J. Configurations and the like of the control device 56 of the present example embodiment are similar to configurations and the like of the control device 56 of the first example embodiment described above.

[0174] The pump 60 is accommodated in the pump accommodation portion 216. The pump 60 is accommodated in the metal housing portion 225. The pump 60 is coupled to the end portion of the shaft 243 on the lower side, that is, the one side (+Z side) in the axial direction. The pump 60 is driven by the power from the motor 40 to pump the oil. The pump 60 of the present example embodiment is a trochoid pump. That is, the electric oil pump 201 of the present example embodiment is a positive displacement electric oil pump. The pump 60 includes the inner rotor 61 and the outer rotor 62. Configurations and the like of the pump 60 of the present example embodiment are similar to configurations and the like of the pump 60 of the first example embodiment described above.

[0175] As illustrated in FIG. 12, the inside of the second suction-side groove portion 33a and the inside of the first suction-side groove portion 228a are connected in the axial direction via a gap G between the inner rotor 61 and the outer rotor 62, and the second suction-side through hole 38a. In the present example embodiment, the internal space of the second suction-side groove portion 33a, the gap G, and the first suction-side groove portion 228a connected to each other are referred to as a suction chamber A1. The suction chamber A1 is connected to the suction port 32a.

[0176] The inside of the second discharge-side groove portion 33c and the inside of the first discharge-side groove portion 228c are connected in the axial direction via the gap G between the inner rotor 61 and the outer rotor 62, and the second discharge-side through hole 38c. In the present example embodiment, the internal space of the second discharge-side groove portion 33c, the gap G, and the internal space of the first discharge-side groove portion 228c connected to each other, are referred to as a compression chamber A2. The compression chamber A2 is connected to the discharge port 232c.

[0177] When the pressure in the suction chamber A1 drops due to the rotation of the inner rotor 61 and the outer rotor 62 while the electric oil pump 201 is operating, the oil flows into the suction chamber A1 through the suction port 32a as indicated by the arrow F1 in FIG. 12. More specifically, although not elaborated in the figures, the oil flowing into the second suction-side groove portion 33a flows through the inside of the second suction-side groove portion 33a in the circumferential direction and is sucked into the gap G via the second suction-side through hole 38a. The oil sucked into the gap G partially flows into the first suction-side groove portion 228a. The oil that has flowed into the first suction-side groove portion 228a flows through the inside of the first suction-side groove portion 228a in the circumferential direction and is sucked into the gap G again.

[0178] When the gap G moves in the circumferential direction due to the rotation of the inner rotor 61 and the outer rotor 62, the oil moves from the suction chamber A1 to the compression chamber A2 as indicated by an arrow F2 in FIG. 12. Although not elaborated in the figures, the oil sucked into the gap G partially flows into the first discharge-side groove portion 228c. The oil that has flowed into the first discharge-side groove portion 228c flows through the first discharge-side groove portion 228c in the circumferential direction and is sucked into the gap G again. The oil sucked into the gap G flows into the second discharge-side groove portion 33c via the second discharge-side through hole 38c. The oil that has flowed into the second discharge-side groove portion 33c flows in the circumferential direction inside the second discharge-side groove portion 33c. Thus, when the pressure of the oil in the compression chamber A2 rises, as indicated by the arrow F3 in FIG. 12, the oil in the compression chamber A2 is pumped to the outside of the electric oil pump 201 through the discharge port 232c. Thus, the electric oil pump 201 supplies oil to the attached body 5.

[0179] As described above, the communication groove portion 227h connects the inside of the top wall portion 227 and the first discharge-side groove portion 228c. Therefore, as indicated by the arrow F4 in FIG. 12, the oil sucked into the gap G and the oil inside the first discharge-side groove portion 228c partially flow into the top wall portion 227 and flow toward the upper side between the shaft 243 and the support surface 225a. Therefore, oil can be supplied to a section between the shaft 243 and the support surface 225a. Accordingly, the shaft 243 and the support surface 225a can be suitably lubricated by the oil, and thus the frictional force between the shaft 243 and the support surface 225a can be reduced. As indicated by the arrow F4 in FIG. 12, the oil flowing toward the upper side between the shaft 243 and the support surface 225a flows into the motor accommodation portion 212. Therefore, the oil can be supplied to the inside of the motor accommodation portion 212. As described above, the pressure of the oil in the compression chamber A2 is high. Therefore, in the present example embodiment, the oil can flow into the top wall portion 227 from the first discharge-side groove portion 228c at a high flow rate. Therefore, the shaft 243 and the support surface 225a can be suitably lubricated by the oil, and the amount of oil flowing into the motor accommodation portion 212 can be increased.

[0180] The rotation of the rotor 41 causes the oil flowed into the motor accommodation portion 212 to circulate inside the motor accommodation portion 212, and cool each of the motor 40 and the control device 56. As described above, the first suction-side groove portion 228a is connected to the inside of the motor accommodation portion 212 through the top wall through hole 227c and the outflow hole 218e. Therefore, when the pressure in the suction chamber A1 drops while the electric oil pump 201 is operating, the oil circulating inside the motor accommodation portion 212 partially flows into the first suction-side groove portion 228a through the top wall through hole 227c and the outflow hole 218e as indicated by the arrow F5 in FIG. 12. The oil that has flowed into the first suction-side groove portion 228a is pumped to the outside of the electric oil pump 201 through the discharge port 232c, together with the oil that has flowed into the suction chamber A1 through the suction port 32a.

[0181] According to the present example embodiment, the size of the top wall portion 227 in the axial direction is larger than the size of the circumferential wall portion 26 in the radial direction. Therefore, the rigidity of the top wall portion 227 in the axial direction can be increased as compared with a case where the size of the top wall portion 227 in the axial direction is equal to or less than the size of the circumferential wall portion 26 in the radial direction. Accordingly, the shaft 243 can be stably supported by the first support portion 227g, and thus the rotation of the shaft 243 about the rotation axis J can be stabilized. Therefore, the loss of the driving force transmitted from the motor 40 to the pump 60 can be more suitably reduced. Thus, the reduction in flow rate of oil discharged from the pump 60 can be suppressed. Therefore, the discharge performance of the electric oil pump 201 can be more suitably improved while reducing the weight of the electric oil pump 201.

[0182] According to the present example embodiment, the top wall portion 227 is provided with the first groove portion 228 that is recessed toward the upper side, that is, the other side (−Z side) in the axial direction and extends in the circumferential direction. Therefore, as described above, while the electric oil pump 201 is operating, the oil that has flowed into the pump 60 through the suction port 32a partially flows through the inside of the first groove portion 228 in the circumferential direction and is sucked into the gap G between the inner rotor 61 and the outer rotor 62. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be increased by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of the oil discharged from the pump 60 can be suitably increased.

[0183] According to the present example embodiment, the surface of the top wall portion 227 facing the outer side in the radial direction is provided with the top wall recess portion 227e recessed toward the inner side in the radial direction, and the housing body portion 211 is partially located in the top wall recess portion 227e. Therefore, when the metal housing portion 225 attempts to rotate about the rotational axis J due to the friction force between the shaft 243 and the metal housing portion 225 while the electric oil pump 201 is operating, part of the housing body portion 211 is caught on the inner side surface of the top wall recess portion 227e. Therefore, while the electric oil pump 201 is operating, rotation of the metal housing portion 225 about the rotation axis J can be suppressed.

[0184] According to the present example embodiment, the top wall portion 227 includes the first support portion 227g supporting the shaft 243, the tubular portion 229 includes the second support portion 229c supporting the shaft 243. In the present example embodiment, as described above, the size of the top wall portion 227 in the axial direction is larger than the size of the circumferential wall portion 26 in the radial direction, and thus the size of the top wall portion 227 in the axial direction is easily increased. This makes it easy to increase the axial direction distance between the first support portion 227g and the second support portion 229c relative to the axial direction distance between the first support portion 227g and the portion of the shaft 243 coupled to the inner rotor 61. Therefore, even when the load applied from the pump 60 to the shaft 243 is large, the load applied to each of the first support portion 227g and the second support portion 229c can be suppressed. Therefore, since it is possible to suppress an increase in the friction force between the shaft 243 and each of the first support portion 227g and the second support portion 229c, it is possible to suppress wearing of at least one of the shaft 243, the first support portion 227g, and the second support portion 229c. Therefore, the durability of the electric oil pump 201 can be improved.

[0185] According to the present example embodiment, the pump cover 231 includes the cover protrusion portions 232g, 232h, and 232k that protrude toward the upper side, that is, the other side (−Z side) in the axial direction, and the bottom plate portion 237 is fitted to the cover protrusion portions 232g, 232h, and 232k. As described above, in the present example embodiment, the pump cover 231 is made of resin, and the bottom plate portion 237 is made of metal, and thus, the difference in linear expansion coefficient between the pump cover 231 and the bottom plate portion 237 is large. Therefore, when the pump cover 231 is molded by insert molding using the bottom plate portion 237 as an insert, a difference in the amount of thermal contraction between the pump cover 231 after molding and the bottom plate portion 237 is large, and thus the warpage in the axial direction of the second welded portion 236 located on the outer side in the radial direction of the bottom plate portion 237 is likely to be large. In contrast, in the present example embodiment, after the pump cover 231 is molded, the bottom plate portion 237 is fitted to the cover protrusion portions 232g, 232h, and 232k, so that the bottom plate portion 237 can be fixed to the pump cover 231. Therefore, in the present example embodiment, the warpage of the second welded portion 236 in the axial direction can be suppressed. Therefore, it is possible to suppress a decrease in flatness of the surface of the second welded portion 236 facing the upper side. Accordingly, the second welded portion 236 and the first welded portion 216b can be stably welded over the entire circumference in the circumferential direction, and thus it is possible to suitably suppress the production of a gap between the second welded portion 236 and the first welded portion 216b. Therefore, the airtightness between the housing body portion 211 and the pump cover 231 can be suitably improved, and thus leakage of the oil from between the housing body portion 211 and the pump cover 231 can be suitably suppressed.

[0186] According to the present example embodiment, the bottom plate portion 237 is provided with the pair of second through holes 38 extending through the bottom plate portion 237 in the axial direction, as viewed in the axial direction, the pair of second through holes 38 have shapes that are line-symmetrical to each other with respect to the third virtual straight line VL3 as a virtual straight line passing through a center of the bottom plate portion 237 as a line of symmetry, and the bottom plate portion 237 includes the hole portion 237c extending through the bottom plate portion 237 in the axial direction at a position shifted from the third virtual straight line VL3. Therefore, as described above, the shape of the bottom plate portion 237 as viewed in the axial direction can be asymmetric with respect to the third virtual straight line VL3. Therefore, in the assembly process for the electric oil pump 201, the bottom plate portion 237 is attached to the pump cover 231 while the position of the hole portion 237c with respect to the pump cover 231 is checked, so that it is possible to suppress attachment of the bottom plate portion 237 to the pump cover 231 in a state where the surface of the bottom plate portion 237 facing the axial direction is reversed. Therefore, the bottom plate portion 237 is easily attached to the pump cover 231 appropriately, and thus the operation of attaching the bottom plate portion 237 to the pump cover 231 can be simplified. Therefore, it is possible to suppress an increase in the number of assembly steps for the electric oil pump 201.

[0187] In addition to the hole portion 237c, the bottom plate portion 237 may have a notch extending in the circumferential direction at the end portion of one of the pair of second through holes 38 in the circumferential direction. Also in this case, the shape of the bottom plate portion 237 as viewed in the axial direction can be asymmetric with respect to the third virtual straight line VL3. Therefore, it is possible to suppress the attachment of the bottom plate portion 237 to the pump cover 231 in a state where the surface of the bottom plate portion 237 facing the axial direction is reversed.

[0188] According to the present example embodiment, the electric oil pump 201 is a positive displacement electric oil pump, the housing 210 includes the pump cover 231 that is made of resin and closes the accommodation recess portion 217 from the lower side, that is, the one side (+Z side) in the axial direction, the housing body portion 211 includes the first welded portion 216b facing the pump cover 231, the first welded portion 216b includes the first welded protrusion portion 216c protruding toward the lower side, the pump cover 231 includes the second welded portion 236 facing the housing body portion 211, the second welded portion 236 includes the second welded protrusion portion 236a protruding toward the upper side, that is, the other side (−Z side) in the axial direction, and the first welded protrusion portion 216c and the second welded protrusion portion 236a are welded to each other. In a case where the first welded portion 216b and the second welded portion 236 do not have the first welded protrusion portion 216c and the second welded protrusion portion 236a, respectively, the surface of the first welded portion 216b facing the lower side, the surface of the second welded portion 236 facing the upper side, and the surface of the pump 60 facing the lower side are located on the same plane, and thus it is difficult to weld the first welded portion 216b and the second welded portion 236 in a state where the pump cover 231 and the pump 60 are in contact with each other in the axial direction. Therefore, it is difficult to increase the joint strength between the first welded portion 216b and the second welded portion 236. A known non-positive displacement pump may employ a configuration in which the pump cover 231 is fixed to the housing body portion 211 by welding. However, with the positive displacement pump, since a fluid such as oil having a high viscosity is discharged, a discharge pressure is higher than that in a case where a fluid having a low viscosity such as water is used. Thus, it is difficult to adopt a configuration in which the pump cover 231 is fixed to the housing body portion 211 by welding. Therefore, in the known positive displacement pump, the pump cover 231 is fixed to the housing body portion 211 using a fixing member such as a bolt. That is, while there has been a demand for a smaller size, a lighter weight, and a lower cost regarding a positive displacement pump, it has been a long unsolved problem to employ a configuration in which the pump cover 231 is fixed to the housing body portion 211 by welding without using a fixing member such as a bolt. In view of this, in the present example embodiment, the first welded protrusion portion 216c can be disposed more on the lower side than the surface of the pump 60 facing the lower side, and the second welded protrusion portion 236a can be disposed more on the upper side than the surface of the pump cover 231 facing the upper side, and thus the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded to each other in a state of being reliably in contact with each other in the axial direction. Therefore, in the present example embodiment, the pump cover 231 can be firmly fixed to the housing body portion 211 by welding. Therefore, the number of components of the electric oil pump 201 can be reduced as compared with a case where the housing body portion 211 and the pump cover 231 are fixed to each other using bolts or the like. Further, since the number of components of the electric oil pump 201 can be reduced, the weight of the electric oil pump 201 can be reduced, and the manufacturing cost can be reduced.

[0189] According to the present example embodiment, a size of the first welded protrusion portion 216c in the radial direction is larger than a size of the first welded protrusion portion 216c in the axial direction, and a size of the second welded protrusion portion 236a in the radial direction is larger than a size of the second welded protrusion portion 236a in the axial direction. Therefore, when the first welded portion 216b and the second welded portion 236 are welded, even if the position of the center axis of the pump cover 231 with respect to the center axis of the housing body portion 211 is shifted in the radial direction, the first welded protrusion portion 216c and the second welded protrusion portion 236a are easily brought into contact with each other in the axial direction. Accordingly, in the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a are easily welded to each other in a reliable manner, and thus it is possible to more suitably improve the airtightness between the first welded portion 216b and the second welded portion 236. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0190] According to the present example embodiment, the first welded protrusion portion 216c can be disposed more on the lower side than the surface of the pump 60 facing the lower side, and the second welded protrusion portion 236a can be disposed more on the upper side than the surface of the pump cover 231 facing the upper side, and thus the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded to each other in a state of being reliably in contact with each other in the axial direction. Therefore, in the present example embodiment, the pump cover 231 can be firmly fixed to the housing body portion 211. According to the present example embodiment, a size of the first welded protrusion portion 216c in the radial direction is larger than a size of the first welded protrusion portion 216c in the axial direction, and a size of the second welded protrusion portion 236a in the radial direction is larger than a size of the second welded protrusion portion 236a in the axial direction as described above. Therefore, the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded over a large area, and thus the airtightness between the first welded portion 216b and the second welded portion 236 can be more suitably improved. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231. Further, with this configuration, the airtightness between the housing body portion 211 and the pump cover 231 can be suitably improved by welding the first welded portion 216b and the second welded portion 236 without using a sealing member such as an O-ring, and thus it is possible to suitably suppress leakage of oil from between the housing body portion 211 and the pump cover 231.

[0191] In the present example embodiment, a portion of the second welded portion 236 other than the second welded protrusion portion 236a faces the first welded portion 216b with a gap in the axial direction. When the portion of the second welded portion 236 other than the second welded protrusion portion 236a comes into contact with the first welded portion 216b in the axial direction, the first welded protrusion portion 216c and the second welded protrusion portion 236a are less likely to come into contact with each other in the axial direction, and thus it is difficult to reliably weld the first welded protrusion portion 216c and the second welded protrusion portion 236a. In contrast, in the present example embodiment, the portion of the second welded portion 236 other than the second welded protrusion portion 236a faces the first welded portion 216b in the axial direction with a gap in between, and thus the first welded protrusion portion 216c and the second welded protrusion portion 236a can be more suitably brought into contact with each other in the axial direction. Accordingly, in the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a can be welded to each other in a more reliable manner, and thus it is possible to more suitably improve the airtightness between the first welded portion 216b and the second welded portion 236. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0192] According to the present example embodiment, the second welded portion 236 is located on the outer side in the radial direction of the bottom plate portion 237. Therefore, compared with a configuration in which the second welded portion 236 is located more on the inner side in the radial direction than the edge portion of the bottom plate portion 237 on the outer side in the radial direction, the structure of each of the second welded portion 236 and the first welded portion 216b of the housing body portion 211 can be simplified. In addition, since the second welded portion 236 is located on the outer side in the radial direction of the bottom plate portion 237, it is possible to improve the workability of the work of welding the first welded portion 216b and the second welded portion 236.

[0193] According to the present example embodiment, as illustrated in FIG. 15, the second welded portion 236 (the second welded protrusion portion 236a) overlaps the bottom plate portion 237 in the radial direction. In the present example embodiment, the second welded portion 236 (the second welded protrusion portion 236a) is disposed at a position overlapping the bottom plate portion 237 in the radial direction, and thus it is possible to achieve uniformity of the thickness of the portion of the pump cover 231 from the first plate-shaped portion 236b to the second welded portion 236 (the second welded protrusion portion 236a). Therefore, it is possible to suppress the occurrence of sink in the vicinity of the first plate-shaped portion 236b and the second welded portion 236 (the second welded protrusion portion 236a). Therefore, it is possible to more suitably suppress a decrease in flatness of the surface of the second welded portion 236 facing the upper side. Accordingly, the second welded portion 236 and the first welded portion 216b can be more stably welded over the entire circumference in the circumferential direction, and thus it is possible to more suitably suppress the production of a gap between the second welded portion 236 and the first welded portion 216b. Therefore, the airtightness between the housing body portion 211 and the pump cover 231 can be more suitably improved, and thus leakage of the oil from between the housing body portion 211 and the pump cover 231 can be more suitably suppressed.

[0194] According to the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a overlap the bottom plate portion 237 in the radial direction. Therefore, in the present example embodiment, the first welded protrusion portion 216c and the second welded protrusion portion 236a are welded to each other in the vicinity of the position where the bottom plate portion 237 and the circumferential wall portion 26 are in contact with each other. Accordingly, the first welded protrusion portion 216c and the second welded protrusion portion 236a located in the vicinity of the position where the bottom plate portion 237 and the circumferential wall portion 26 are in contact with each other can block the oil leakage from the inside of the metal housing portion 25. Therefore, the amount of oil leaking from the inside of the metal housing portion 25 can be reduced. Therefore, it is possible to suitably suppress a decrease in the flow rate of the oil discharged from the pump 60. Therefore, the volumetric efficiency of the pump 60 can be increased, and a decrease in the pump efficiency can be suppressed.

[0195] According to the present example embodiment, the bottom plate portion 237 comes into contact with the circumferential wall portion 26 in the axial direction. Therefore, it is easy to suppress the direct contact between the pump 60 and the pump cover 231 made of resin via the gap between the bottom plate portion 237 and the circumferential wall portion 26. Therefore, while the electric oil pump 201 is operating, it is possible to more suitably suppress the wearing of the pump cover 231 due to the friction with the inner rotor 61 and the outer rotor 62. Therefore, the durability of the electric oil pump 201 can be more suitably improved.

[0196] According to the present example embodiment, the housing body portion 211 includes the pump accommodation portion 216 that surrounds the pump 60 from the outer side in the radial direction, and the motor accommodation portion 212 that accommodates the motor 40 and is provided more on the upper side, that is the other side (−Z side) in the axial direction than the pump accommodation portion 216, the plurality of ribs 220 are provided on the surface of the pump accommodation portion 216 facing the outer side in the radial direction, and the plurality of ribs 220 are spaced apart from each other along the circumferential direction, and connect in the axial direction, the surface of the motor accommodation portion 212 facing the lower side, that is, the one side (+Z side) in the axial direction and the first welded portion 216b. Therefore, as described above, in the present example embodiment, when the housing body portion 211 is molded, the plurality of ribs 220 can suppress warpage of the first welded portion 216b to have a portion more on the outer side in the radial direction located more on the upper side. Therefore, it is possible to suppress a decrease in flatness of the surface of the first welded portion 216b facing the lower side. Accordingly, the first welded portion 216b and the second welded portion 236 can be more reliably welded, and thus the airtightness between the housing body portion 211 and the pump cover 231 can be more suitably improved. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0197] In the present example embodiment, as described above, the pump cover 231 includes the plurality of cover ribs 235 protruding from the outer surface of the pump cover 231, and the end portion of each cover rib 235 on the upper side is connected to the surface of the second welded portion 236 facing the lower side. Therefore, when the pump cover 231 is molded, the cover ribs 235 can suppress the warpage of the second welded portion 236 to have a portion more on the outer side in the radial direction located more on the lower side as described above. Therefore, it is possible to suppress a decrease in flatness of the surface of the second welded portion 236 facing the upper side. Accordingly, the first welded portion 216b and the second welded portion 236 can be more reliably welded, and thus the airtightness between the housing body portion 211 and the pump cover 231 can be more suitably improved. Therefore, it is possible to more suitably suppress the leakage of oil from between the housing body portion 211 and the pump cover 231.

[0198] According to the present example embodiment, the electric oil pump 201 further includes the circuit board 57 that is provided more on the upper side, that is, the other side (−Z side) in the axial direction than the motor 40 and supplies current to the motor 40, the housing 210 includes the lid portion 221 made of resin that accommodates the circuit board 57, the housing body portion 211 includes the third welded portion 212d facing the lid portion 221, the lid portion 221 includes the fourth welded portion 222a facing the third welded portion 212d, and the third welded portion 212d and the fourth welded portion 222a are welded to each other. Therefore, since the housing body portion 211 and the lid portion 221 can be fixed by welding, the number of components of the electric oil pump 201 can be reduced as compared with a case where the housing body portion 211 and the lid portion 221 are fixed using bolts or the like.

[0199] While the example embodiments of the present disclosure have been described above, the configurations in the example embodiments, combinations thereof, and the like are an example, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present disclosure. Note that the present disclosure is not limited to the example embodiments described above.

[0200] The pump cover may be made of metal. In this case as well, the housing body portion is made of resin, and thus the weight of the housing can be reduced. Therefore, the weight of the electric oil pump can be reduced. In this case, the housing may not have the bottom plate portion.

[0201] The metal housing portion may not have the tubular portion. In this case, the shaft and the inner circumferential surface of the communication hole portion can be lubricated using oil, and thus wearing of the inner circumferential surface of the communication hole portion can be suppressed.

[0202] The metal housing portion may be fixed to the housing body portion using an adhesive or the like. Also in this case, each of the circumferential wall portion, the top wall portion, and the tubular portion can suppress wearing of the housing body portion. The bottom plate portion may be fixed to the pump cover using an adhesive or the like. Also in this case, the bottom plate portion can suppress the wearing of the pump cover.

[0203] The pump cover may include the pump accommodation portion. With this configuration, the metal housing portion is accommodated in the pump accommodation portion of the pump cover, the bottom plate portion is fixed to the housing body portion, and the housing body portion is provided with the first groove portion. With this configuration, the bottom plate portion may have a tubular portion extending toward the other side in the axial direction, and a rib may be provided at a corner portion between the bottom plate portion and the tubular portion to improve the strength for supporting the shaft.

[0204] The lid portion may include a metal plate for preventing an influence of electromagnetic noise. In this case, the lid portion may have a protrusion portion to which the metal plate is fitted, such that the pump cover has a cover protrusion portion to which the bottom plate portion is fitted. That is, the lid portion may have a protrusion portion for fixing the metal plate. The metal plate may be fixed to the lid portion by thermal caulking. The protrusion portion of the lid portion may be provided at a portion of the lid portion on the inner side in the radial direction or may have a stepped shape to prevent the flatness of the fourth welded portion from being compromised.

[0205] While in the above-described example embodiment, the circuit board is provided more on the other side in the axial direction than the motor, the circuit board may be disposed at another position. The circuit board may be disposed along the axial direction. In the case where the circuit board is disposed along the axial direction, the housing body portion or the lid portion can have a board accommodation portion that is open in the radial direction and accommodates the circuit board. The board accommodation portion of the housing body portion or the board accommodation portion of the lid portion can appropriately accommodate the circuit board, a member electrically connecting the stator and the circuit board, and the like and can have a minimum possible size in the radial direction by appropriately configuring the wall portion having the height in the radial direction. Further, since the circuit board is not disposed more on the other side in the axial direction than the motor, the size in the axial direction can be made small. The wall portion having the height in the radial direction may be included in both the housing body portion and the lid portion, or may be included in only one of the housing body portion and the lid portion. When the circuit board is disposed along the axial direction, the third welded portion of the housing body portion and the fourth welded portion of the lid portion can be welded in the radial direction by configuring the first projection portion and the second annular groove portion to be oriented in the radial direction. The first projection portion and the second annular groove portion are formed in a rectangular frame shape having a long side in the axial direction and a short side in the radial direction, so that the section between the housing body portion and the lid portion can be sealed without using a sealing member such as an O-ring while the size of the board accommodation portion is set to a minimum necessary size along the shape of the circuit board.

[0206] The housing body portion or the lid portion may include a columnar boss made of resin from an inner side surface serving as the board accommodation portion. The boss of the housing body portion or the lid portion may be inserted in a hole formed in the circuit board, and the circuit board may be fixed by thermal caulking.

[0207] The use of the electric oil pump to which the present disclosure is applied is not particularly limited. The type of fluid fed by the electric oil pump is not particularly limited, and may be a liquid other than oil, such as water. The electric oil pump may be installed in an attached body other than the vehicle. The configurations described above in the present specification can be combined as appropriate within a range in which they do not contradict each other.

[0208] Note that the present technology can have configurations such as the following.

[0209] (1) An electric oil pump including a shaft extending in an axial direction, a motor including a rotor that is rotatably fixed to the shaft and a stator facing the rotor with a gap in a radial direction, a pump driven to pump oil by power of the motor, and a housing accommodating the motor and the pump, wherein the pump includes an inner rotor coupled to the shaft on one side in the axial direction and including external teeth, and an outer rotor surrounding the inner rotor from an outer side in the radial direction and including internal teeth meshing with the external teeth, the housing includes a housing body portion made of resin and a metal housing portion made of metal, the housing body portion includes an accommodation recess portion that is recessed from an end portion on one side in the axial direction toward another side in the axial direction and accommodates the pump, and a stator holding portion that holds the stator, the accommodation recess portion includes a recess portion inner circumferential surface surrounding the pump from the outer side in the radial direction, the metal housing portion is at least partially embedded in the housing body portion, and the metal housing portion includes a cylindrical circumferential wall portion between the pump and the recess portion inner circumferential surface in the radial direction.

[0210] (2) The electric oil pump according to (1), wherein the accommodation recess portion includes a top surface that is located more on the other side in the axial direction than the pump and faces the pump in the axial direction, and the metal housing portion includes a top wall portion between the pump and the top surface in the axial direction.

[0211] (3) The electric oil pump according to (2), wherein an end portion of the circumferential wall portion on the other side in the axial direction is connected to an end portion of the top wall portion on the outer side in the radial direction over entire circumference in a circumferential direction.

[0212] (4) The electric oil pump according to (2) or (3), wherein the top wall portion is provided with a first through hole extending through the top wall portion in the axial direction, and a surface of the top wall portion facing the one side in the axial direction is located more on the one side in the axial direction than the top surface.

[0213] (5) The electric oil pump according to any one of (2) to (4), wherein the top wall portion is provided with a first through hole extending through the top wall portion in the axial direction, the top surface is provided with a first groove portion that is recessed toward the other side in the axial direction and extends in a circumferential direction, and the first through hole at least partially overlaps the first groove portion as viewed in the axial direction.

[0214] (6) The electric oil pump according to (2) or (3), wherein a size of the top wall portion in the axial direction is larger than a size of the circumferential wall portion in the radial direction.

[0215] (7) The electric oil pump according to (6), wherein the top wall portion is provided with a first groove portion that is recessed toward the other side in the axial direction and extends in a circumferential direction.

[0216] (8) The electric oil pump according to (6) or (7), wherein a surface of the top wall portion facing the outer side in the radial direction is provided with a top wall recess portion recessed toward an inner side in the radial direction, and the housing body portion is partially located inside the top wall recess portion.

[0217] (9) The electric oil pump according to any one of (2) to (8), wherein the housing body portion includes a motor accommodation portion that accommodates the motor, a communication hole portion through which the shaft passes in the axial direction, the communication hole portion connecting an inside of the motor accommodation portion and an inside of the accommodation recess portion, the top wall portion has an annular plate shape expanding in the radial direction, the metal housing portion includes a tubular portion having a tubular shape and extending from an inner edge of the top wall portion in the radial direction toward the other side in the axial direction, and the tubular portion is between the shaft and an inner circumferential surface of the communication hole portion in the radial direction.

[0218] (10) The electric oil pump according to (9), wherein the top wall portion includes a first support portion that supports the shaft, and the tubular portion includes a second support portion that supports the shaft.

[0219] (11) The electric oil pump according to any one of (1) to (10), wherein the housing body portion is molded by insert molding using the metal housing portion as an insert.

[0220] (12) The electric oil pump according to any one of (1) to (11), wherein the housing includes a pump cover made of resin and closing the accommodation recess portion from the one side in the axial direction, and a bottom plate portion that is made of metal, that is fixed to a surface of the pump cover facing the other side in the axial direction, and that faces the pump in the axial direction.

[0221] (13) The electric oil pump according to (12), wherein an end portion of the bottom plate portion on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion.

[0222] (14) The electric oil pump according to (12) or (13), wherein a surface of the pump cover facing the other side in the axial direction is provided with a second groove portion that is recessed toward the one side in the axial direction and extends in a circumferential direction, the bottom plate portion is provided with a second through hole extending through the bottom plate portion in the axial direction, and the second through hole at least partially overlaps the second groove portion as viewed in the axial direction.

[0223] (15) The electric oil pump according to any one of (12) to (14), wherein the pump cover is molded by insert molding using the bottom plate portion as an insert.

[0224] (16) The electric oil pump according to any one of (12) to (14), wherein the pump cover includes a cover protrusion portion protruding toward the other side in the axial direction, and the bottom plate portion is fitted to the cover protrusion portion.

[0225] (17) The electric oil pump according to (16), wherein the bottom plate portion is provided with a pair of second through holes extending through the bottom plate portion in the axial direction, as viewed in the axial direction, the pair of second through holes have shapes that are line-symmetrical to each other with respect to a virtual straight line passing through a center of the bottom plate portion as a line of symmetry, and the bottom plate portion includes a hole portion extending through the bottom plate portion in the axial direction at a position shifted from the virtual straight line.

[0226] (18) The electric oil pump according to any one of (1) to (17), wherein the electric oil pump is a positive displacement electric oil pump, the housing includes a pump cover that is made of resin and closes the accommodation recess portion from the one side in the axial direction, the housing body portion includes a first welded portion facing the pump cover, the first welded portion includes a first welded protrusion portion protruding toward the one side in the axial direction, the pump cover includes a second welded portion facing the housing body portion, the second welded portion includes a second welded protrusion portion protruding toward the other side in the axial direction, and the first welded protrusion portion and the second welded protrusion portion are welded to each other.

[0227] (19) The electric oil pump according to (18), wherein a size of the first welded protrusion portion in the radial direction is larger than a size of the first welded protrusion portion in the axial direction, and a size of the second welded protrusion portion in the radial direction is larger than a size of the second welded protrusion portion in the axial direction.

[0228] (20) The electric oil pump according to (18) or (19), wherein a portion of the second welded portion other than the second welded protrusion portion faces the first welded portion in the axial direction with a gap in between.

[0229] (21) The electric oil pump according to any one of (18) to (20), wherein the pump cover includes a cover protrusion portion protruding toward the other side in the axial direction, and the housing includes a bottom plate portion made of metal and fitted to the cover protrusion portion.

[0230] (22) The electric oil pump according to (21), wherein the second welded portion is located on the outer side in the radial direction of the bottom plate portion.

[0231] (23) The electric oil pump according to (21) or (22), wherein the bottom plate portion is in contact with the circumferential wall portion in the axial direction.

[0232] (24) The electric oil pump according to any one of (18) to (23), wherein the housing body portion includes a pump accommodation portion surrounding the pump from the outer side in the radial direction, and a motor accommodation portion that accommodates the motor and is provided more on the other side in the axial direction than the pump accommodation portion, a plurality of ribs are provided on a surface of the pump accommodation portion facing the outer side in the radial direction, and the plurality of ribs are spaced apart from each other along a circumferential direction, and connect in the axial direction, the motor accommodation portion on the one side in the axial direction and the first welded portion.

[0233] (25) The electric oil pump according to any one of (18) to (24) further including a circuit board that is provided more on the other side in the axial direction than the motor and supplies a current to the motor, wherein the housing includes a lid portion made of resin that accommodates the circuit board, the housing body portion includes a third welded portion facing the lid portion, the lid portion includes a fourth welded portion facing the third welded portion, and the third welded portion and the fourth welded portion are welded to each other.

[0234] (26) A housing body portion made of resin, the housing body portion at least partially accommodating a motor and a pump in a positive displacement electric oil pump, and being welded to a pump cover made of resin, the housing body portion having a cylindrical shape extending in an axial direction, the housing body portion including a first welded portion at an end portion in the axial direction, wherein the first welded portion includes a first welded protrusion portion protruding in the axial direction and welded to a second welded portion of the pump cover.

[0235] (27) A pump cover made of resin and welded to a housing body portion made of resin, the housing body portion at least partially accommodating a motor and a pump in a positive displacement electric oil pump, the pump cover including a second welded portion at an end portion in an axial direction, wherein the second welded portion includes a second welded protrusion portion protruding in the axial direction and welded to a first welded portion of the housing body portion.

[0236] Features of the above-described preferred example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

[0237] While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0026]Hereinafter, electric oil pumps according to example embodiments of the present disclosure will be described with reference to the drawings. The scope of the present disclosure is not limited to the following example embodiments, and can be arbitrarily changed within the scope of the technical ideas of the present disclosure. In the drawings described below, in order to make each configuration easy to understand, the scale, the number, and the like in each structure may be different from those in the actual structure.

[0027]In each drawing, a Z axis is illustrated as appropriate. The direction in which the Z axis extends is the direction in which a rotation axis J of the example embodiments described below extends. The rotation axis J in each diagram is a virtual axis. In the following description, the direction in which the rotation axis J extends, that is, a direction parallel to the Z axis is referred to as an “axial direction”. A side in the axial direction toward which an ...

Claims

1. An electric oil pump comprising:a shaft extending in an axial direction;a motor including:a rotor that is rotatably fixed to the shaft; anda stator facing the rotor with a gap in a radial direction;a pump driven to pump oil by power of the motor; anda housing accommodating the motor and the pump; wherein the pump includes:an inner rotor coupled to the shaft on one side in the axial direction and including external teeth; andan outer rotor surrounding the inner rotor from an outer side in the radial direction and including internal teeth meshing with the external teeth;the housing includes a housing body portion made of resin and a metal housing portion made of metal;the housing body portion includes:an accommodation recess portion that is recessed from an end portion on one side in the axial direction toward another side in the axial direction and accommodates the pump; anda stator holding portion that holds the stator;the accommodation recess portion includes a recess portion inner circumferential surface surrounding the pump from the outer side in the radial direction;the metal housing portion is at least partially embedded in the housing body portion; andthe metal housing portion includes a cylindrical circumferential wall portion between the pump and the recess portion inner circumferential surface in the radial direction.

2. The electric oil pump according to claim 1, whereinthe accommodation recess portion includes a top surface that is located more on the other side in the axial direction than the pump and faces the pump in the axial direction; andthe metal housing portion includes a top wall portion between the pump and the top surface in the axial direction.

3. The electric oil pump according to claim 2, wherein an end portion of the circumferential wall portion on the other side in the axial direction is connected to an end portion of the top wall portion on the outer side in the radial direction over entire circumference in a circumferential direction.

4. The electric oil pump according to claim 2, whereinthe top wall portion is provided with a first through hole extending through the top wall portion in the axial direction; anda surface of the top wall portion facing the one side in the axial direction is located more on the one side in the axial direction than the top surface.

5. The electric oil pump according to claim 2, whereinthe top wall portion is provided with a first through hole extending through the top wall portion in the axial direction;the top surface is provided with a first groove portion that is recessed toward the other side in the axial direction and extends in a circumferential direction; andthe first through hole at least partially overlaps the first groove portion as viewed in the axial direction.

6. The electric oil pump according to claim 2, wherein a size of the top wall portion in the axial direction is larger than a size of the circumferential wall portion in the radial direction.

7. The electric oil pump according to claim 6, wherein the top wall portion is provided with a first groove portion that is recessed toward the other side in the axial direction and extends in a circumferential direction.

8. The electric oil pump according to claim 6, whereina surface of the top wall portion facing the outer side in the radial direction is provided with a top wall recess portion recessed toward an inner side in the radial direction; andthe housing body portion is partially located inside the top wall recess portion.

9. The electric oil pump according to claim 2, whereinthe housing body portion includes:a motor accommodation portion that accommodates the motor;a communication hole portion through which the shaft passes in the axial direction, the communication hole portion connecting an inside of the motor accommodation portion and an inside of the accommodation recess portion;the top wall portion has an annular plate shape expanding in the radial direction;the metal housing portion includes a tubular portion having a tubular shape and extending from an inner edge of the top wall portion in the radial direction toward the other side in the axial direction; andthe tubular portion is between the shaft and an inner circumferential surface of the communication hole portion in the radial direction.

10. The electric oil pump according to claim 9, whereinthe top wall portion includes a first support portion that supports the shaft; andthe tubular portion includes a second support portion that supports the shaft.

11. The electric oil pump according to claim 1, wherein the housing body portion is molded by insert molding using the metal housing portion as an insert.

12. The electric oil pump according to claim 1, wherein the housing includes a pump cover made of resin and closing the accommodation recess portion from the one side in the axial direction, and a bottom plate portion that is made of metal, that is fixed to a surface of the pump cover facing the other side in the axial direction, and that faces the pump in the axial direction.

13. The electric oil pump according to claim 12, wherein an end portion of the bottom plate portion on the outer side in the radial direction is located more on the outer side in the radial direction than the circumferential wall portion.

14. The electric oil pump according to claim 12, whereina surface of the pump cover facing the other side in the axial direction is provided with a second groove portion that is recessed toward the one side in the axial direction and extends in a circumferential direction;the bottom plate portion is provided with a second through hole extending through the bottom plate portion in the axial direction; andthe second through hole at least partially overlaps the second groove portion as viewed in the axial direction.

15. The electric oil pump according to claim 12, wherein the pump cover is molded by insert molding using the bottom plate portion as an insert.

16. The electric oil pump according to claim 12, whereinthe pump cover includes a cover protrusion portion protruding toward the other side in the axial direction; andthe bottom plate portion is fitted to the cover protrusion portion.

17. The electric oil pump according to claim 16, whereinthe bottom plate portion is provided with a pair of second through holes extending through the bottom plate portion in the axial direction;as viewed in the axial direction, the pair of second through holes have shapes that are line-symmetrical to each other with respect to a virtual straight line passing through a center of the bottom plate portion as a line of symmetry; andthe bottom plate portion includes a hole portion extending through the bottom plate portion in the axial direction at a position shifted from the virtual straight line.

18. The electric oil pump according to claim 1, whereinthe electric oil pump is a positive displacement electric oil pump;the housing includes a pump cover that is made of resin and closes the accommodation recess portion from the one side in the axial direction;the housing body portion includes a first welded portion facing the pump cover;the first welded portion includes a first welded protrusion portion protruding toward the one side in the axial direction;the pump cover includes a second welded portion facing the housing body portion;the second welded portion includes a second welded protrusion portion protruding toward the other side in the axial direction; andthe first welded protrusion portion and the second welded protrusion portion are welded to each other.

19. The electric oil pump according to claim 18, whereina size of the first welded protrusion portion in the radial direction is larger than a size of the first welded protrusion portion in the axial direction; anda size of the second welded protrusion portion in the radial direction is larger than a size of the second welded protrusion portion in the axial direction.

20. The electric oil pump according to claim 18, wherein a portion of the second welded portion other than the second welded protrusion portion faces the first welded portion in the axial direction with a gap in between.

21. The electric oil pump according to claim 18, whereinthe pump cover includes a cover protrusion portion protruding toward the other side in the axial direction, andthe housing includes a bottom plate portion made of metal and fitted to the cover protrusion portion.

22. The electric oil pump according to claim 21, wherein the second welded portion is located on the outer side in the radial direction of the bottom plate portion.

23. The electric oil pump according to claim 21, wherein the bottom plate portion is in contact with the circumferential wall portion in the axial direction.

24. The electric oil pump according to claim 18, whereinthe housing body portion includes a pump accommodation portion surrounding the pump from the outer side in the radial direction, and a motor accommodation portion that accommodates the motor and is provided more on the other side in the axial direction than the pump accommodation portion;a plurality of ribs are provided on a surface of the pump accommodation portion facing the outer side in the radial direction; andthe plurality of ribs are spaced apart from each other along a circumferential direction, and connect in the axial direction, the motor accommodation portion on the one side in the axial direction and the first welded portion.

25. The electric oil pump according to claim 18, further comprising a circuit board that is provided more on the other side in the axial direction than the motor and supplies a current to the motor; whereinthe housing includes a lid portion made of resin that accommodates the circuit board;the housing body portion includes a third welded portion facing the lid portion;the lid portion includes a fourth welded portion facing the third welded portion; andthe third welded portion and the fourth welded portion are welded to each other.

26. A housing body portion comprising:a structure made of resin and configured to at least partially accommodate a motor and a pump in a positive displacement electric oil pump, and being welded to a pump cover made of resin, the housing body portion having a cylindrical shape extending in an axial direction; anda first welded portion located at an end portion in the axial direction and including a first welded protrusion portion protruding in the axial direction and welded to a second welded portion of the pump cover.

27. A pump cover comprising:a structure made of resin and welded to a housing body portion made of resin and configured to at least partially accommodate a motor and a pump in a positive displacement electric oil pump; anda second welded portion located at an end portion in an axial direction and including a second welded protrusion portion protruding in the axial direction and welded to a first welded portion of the housing body portion.

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