Electric oil pump, housing main body portion, and pump cover

Abstract

The electric oil pump of the present invention comprises: a motor unit having an axially extending shaft, a rotor fixed to the shaft and rotatable, and a stator; a pump unit driven by the power of the motor unit to pump oil; and a housing housing the motor unit and the pump unit. The pump unit has: an inner rotor connected to the shaft; and an outer rotor surrounding the inner rotor from the radially outer side. The housing has a resin housing body and a metal housing body. The housing body has: a receiving recess recessed axially to the other side to house the pump unit; and a stator retaining portion to retain the stator. The receiving recess has an inner circumferential surface surrounding the pump unit from the radially outer side. At least a portion of the metal housing body is embedded in the housing body. The metal housing body has a cylindrical peripheral wall portion disposed between the pump unit and the inner circumferential surface of the recess.

Description

Technical Field

[0001] This invention relates to an electric oil pump, a housing body, and a pump cover. Background Technology

[0002] An oil pump is known, comprising: a resin motor housing that houses a motor portion having a rotating shaft; and a metal pump housing that houses a pumping gear that rotates via the rotating shaft, wherein the pump housing is fixed to the motor housing by a plurality of locking tabs provided in the motor housing (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Korean Patent Application Publication No. 2025-0013111 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the aforementioned oil pump, the difference in the coefficient of linear expansion between the resin motor housing and the metal pump housing is significant. Therefore, if the pump temperature fluctuates, the holding force of the retaining plates in holding the pump housing may change substantially. Consequently, in the aforementioned oil pump, if the pump temperature fluctuates, the positional accuracy between the central shaft of the motor section and the central shaft of the pumping gear may decrease, thus increasing the loss of driving force transmitted from the motor section to the pumping gear. Therefore, in the aforementioned oil pump, the flow rate of oil discharged from the pump section may decrease.

[0008] In view of the above circumstances, one objective of this invention is to provide an electric oil pump that can achieve lightweight design and suppress the reduction in the flow rate of oil discharged from the pump section.

[0009] Solution for solving the problem

[0010] One embodiment of the electric oil pump of the present invention comprises: a motor unit having an axially extending shaft, a rotor fixed to the shaft and rotatable, and a stator radially spaced apart from the rotor; a pump unit driven by the power of the motor unit to pressurize oil; and a housing housing the motor unit and the pump unit. The pump unit has: an inner rotor connected to one axial side of the shaft and having external teeth; and an outer rotor surrounding the inner rotor from the radially outer side and having internal teeth that mesh with the external teeth. The housing has a resin housing body and a metal housing body. The housing body has: a receiving recess recessing from one axial side end to the other axial side and housing the pump unit therein; and a stator retaining portion holding the stator. The receiving recess has an inner circumferential surface surrounding the pump unit from the radially outer side. At least a portion of the metal housing body is embedded in the housing body. The metal housing body has a cylindrical peripheral wall portion radially disposed between the pump unit and the inner circumferential surface of the recess.

[0011] The housing body is a resin housing body in a positive displacement electric oil pump that houses at least a portion of the pump section and the motor section and is fused to a resin pump cover. The housing body is a cylindrical shape extending axially. The housing body has a first fusion portion at its axial end. The first fusion portion has a first fusion protrusion that protrudes axially and is fused to a second fusion portion of the pump cover.

[0012] The pump cover is a resin-made pump cover that is fused to a resin-made housing body that houses at least a portion of the pump section and the motor section in a positive displacement electric oil pump. The pump cover has a second welded portion at an axial end, the second welded portion having a second welded protrusion that protrudes axially and is fused to a first welded portion of the housing body.

[0013] Invention Effects

[0014] According to one aspect of the present invention, a lightweight design can be achieved in the electric oil pump, and the reduction in the flow rate of oil discharged from the pump section can be suppressed. Attached Figure Description

[0015] Figure 1 This is a first perspective view showing the electric oil pump according to the first embodiment.

[0016] Figure 2 This is a cross-sectional view showing the electric oil pump according to the first embodiment.

[0017] Figure 3 This is an enlarged cross-sectional view showing a portion of the electric oil pump according to the first embodiment.

[0018] Figure 4This is a cross-sectional view showing the electric oil pump of the first embodiment, and is... Figure 3 Sectional view IV-IV.

[0019] Figure 5 This is a second perspective view showing the electric oil pump according to the first embodiment.

[0020] Figure 6 This is a top view of the pump cover and base plate of the first embodiment viewed from the other side of the axial direction.

[0021] Figure 7 This is a perspective view showing the metal casing portion of the first embodiment.

[0022] Figure 8 This is a perspective view showing the base plate portion of the first embodiment.

[0023] Figure 9 This is a cross-sectional view showing the electric oil pump of the first embodiment, and is... Figure 3 IX-IX sectional view.

[0024] Figure 10 This is a perspective view showing the electric oil pump according to the second embodiment.

[0025] Figure 11 This is a cross-sectional view showing the electric oil pump according to the second embodiment.

[0026] Figure 12 This is a first enlarged cross-sectional view showing a portion of the electric oil pump according to the second embodiment.

[0027] Figure 13 This is a cross-sectional view showing the electric oil pump according to the second embodiment, and is... Figure 12 Sectional view of VIII-VIII.

[0028] Figure 14 This is a top view of the pump cover and base plate of the second embodiment viewed from the other side of the axial direction.

[0029] Figure 15 This is a second enlarged cross-sectional view showing a portion of the electric oil pump according to the second embodiment.

[0030] Figure 16 This is a cross-sectional view showing the electric oil pump according to the second embodiment, and is... Figure 12 XVI-XVI sectional view.

[0031] Figure 17 This is a perspective view showing the metal casing portion of the second embodiment.

[0032] Explanation of reference numerals in the attached figures

[0033] 1, 201: Electric oil pump; 10, 210: Housing; 11, 211: Main body of housing; 12, 212: Motor housing; 12g: Stator retaining part; 16, 216: Pump housing; 17, 217: Receiving recess; 17a, 217a: Inner peripheral surface of recess; 17e, 217e: Top surface; 18c, 218c: Connecting hole; 19, 228: First groove; 21, 221: Cover; 25, 225: Metal housing; 26: Peripheral wall; 27, 227: Top wall; 28: First through hole; 29, 229: Cylindrical part; 31, 231: Pump cover; 33: Second groove; 37, 237: Base plate; 38 : Second through hole; 40: Motor part; 41: Rotor; 43, 243: Shaft; 50: Stator; 57: Circuit board; 60: Pump part; 61: Inner rotor; 61a: External tooth; 62: External rotor; 62a: Internal tooth; 212d: Third welded part; 216b: First welded part; 216c: First welded protrusion; 220: Rib; 222a: Fourth welded part; 227e: Top wall recess; 227g: First support part; 229c: Second support part; 232g, 232h, 232k: Cover protrusion; 236: Second welded part; 236a: Second welded protrusion; 237c: Hole; VL3: Third imaginary straight line (imaginary straight line). Detailed Implementation

[0034] Hereinafter, an electric oil pump according to an embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that the scope of the present invention is not limited to the following embodiments, and modifications can be made arbitrarily within the scope of the technical concept of the present invention. Furthermore, in the following drawings, for ease of understanding of the various components, the actual structure may sometimes differ from the scale, quantity, etc., of each component.

[0035] In each figure, the Z-axis is appropriately shown. The direction in which the Z-axis extends is the direction in which the rotation axis J extends in the embodiments described below. The rotation axis J shown in each figure is an imaginary axis. In the following description, the direction in which the rotation axis J extends, that is, the direction parallel to the Z-axis, is called the "axial direction". The side in the axial direction where the arrow of the Z-axis points (+Z side) is called the "axial side" or "lower side", and the side in the axial direction opposite to the side in the Z-axis direction (-Z side) is called the "axial other side" or "upper side". In the following description, the radial direction centered on the rotation axis J is simply referred to as "radial", and the circumferential direction centered on the rotation axis J is simply referred to as "circumferential direction". It should be noted that "upper side" and "lower side" are merely names used to describe the relative positional relationship of each part, and the relative positional relationship of each part may also be a configuration relationship other than that indicated by these names.

[0036] The circumferential direction is represented by arrow θ in each diagram. The side in the circumferential direction that arrow θ points towards (the +θ side) is called the "circumferential side". The side in the circumferential direction opposite to the side in the direction arrow θ points towards (the -θ side) is called the "circumferential side". The circumferential side is the side that moves clockwise around the axis of rotation J when viewed from above. The circumferential side is the side that moves counterclockwise around the axis of rotation J when viewed from above.

[0037] <First Implementation Method>

[0038] Figure 1 This is a perspective view showing the electric oil pump 1 according to this embodiment. The electric oil pump 1 of this embodiment is an electric oil pump that delivers oil as a fluid. The fluid may also be other liquids such as water. The electric oil pump 1 is used, for example, to supply oil to a mounted device such as a vehicle. The mounted device may be an automatic transmission or a drive unit that drives the axle of the vehicle. Figure 2 As shown, the electric oil pump 1 includes a housing 10, a motor 40, a shaft 43, a control device 56, and a pump 60.

[0039] The outer casing 10 is a generally cylindrical shape extending axially. The outer casing 10 houses the motor unit 40, shaft 43, control device 56, and pump unit 60. The outer casing 10 has a main casing portion 11, a cover portion 21, a metal casing portion 25, a pump cover 31, and a base plate portion 37. In this embodiment, the main casing portion 11, cover portion 21, metal casing portion 25, pump cover 31, and base plate portion 37 are independent components.

[0040] The main body 11 of the housing is a generally cylindrical shape extending axially around the rotation axis J. The main body 11 houses the motor part 40, the shaft 43, and the pump part 60. In this embodiment, the main body 11 is made of resin. Polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), and polycarbonate (PC) can be used as materials constituting the main body 11. In this embodiment, the main body 11 is formed by molding the metal housing part 25 and the stator 50 (described later) of the motor part 40 as inserts. At least a portion of the metal housing part 25 is embedded in the main body 11. Thus, the metal housing part 25 is fixed to the main body 11. Therefore, in the assembly process of the electric oil pump 1, for example, it is not necessary to fix the metal housing part 25 to the main body 11 using adhesive, thereby suppressing the increase in assembly time of the electric oil pump 1. Furthermore, the stator 50 is embedded inside the main body 11. The main body 11 of the housing has a motor housing 12, a pump housing 16, and a rib 20.

[0041] The motor housing 12 is the upper part of the housing body 11. The motor housing 12 is generally cylindrical and extends axially about the rotation axis J. The motor housing 12 has an opening at the top. The motor housing 12 houses the motor part 40. The motor housing 12 has a first sidewall part 12a, a stator holding part 12g, and a mounting part 14.

[0042] The first sidewall portion 12a is a generally cylindrical shape extending axially around the rotation axis J. The first sidewall portion 12a surrounds the upper parts of the motor portion 40 and the shaft 43 from the radially outer side. A cover portion 21 is fixed to the upper end of the first sidewall portion 12a. The first sidewall portion 12a is provided with a first annular groove portion 12c and a first protrusion portion 12e.

[0043] The first annular groove 12c is a groove that is recessed radially inward from the radially outward surface of the first sidewall 12a and extends circumferentially. The first annular groove 12c extends circumferentially all around. An O-ring 91 is embedded inside the first annular groove 12c. The first protrusion 12e is a protrusion that protrudes upward from the upward surface of the first sidewall 12a. The first protrusion 12e extends circumferentially all around.

[0044] The stator holding portion 12g is approximately annular about the rotation axis J. The stator holding portion 12g is positioned radially inward from the first sidewall portion 12a. The stator holding portion 12g is connected to the first sidewall portion 12a. The stator 50, which is part of the motor portion 40 and will be described later, is embedded inside the stator holding portion 12g. Therefore, the housing body portion 11 holds the stator 50. A substrate holding portion 12h is provided in the stator holding portion 12g.

[0045] The substrate holding portion 12h is a columnar shape that protrudes upward from the upward-facing surface of the stator holding portion 12g. Although not shown in the figure, multiple substrate holding portions 12h are provided in the stator holding portion 12g. The substrate holding portions 12h are arranged at intervals from each other along the circumferential direction.

[0046] The mounting portion 14 protrudes radially outward from the radially outward surface of the first sidewall portion 12a. The mounting portion 14 is provided with a hole 14a that penetrates the mounting portion 14 axially. For example... Figure 1 As shown, in this embodiment, the motor housing 12 has two mounting portions 14. The motor housing 12 may also have three or more mounting portions 14. Each mounting portion 14 is radially opposed to the other across the rotation axis J. A collar portion 14c is inserted into each hole 14a. Each collar portion 14c is fixed to the inner circumferential surface of the hole 14a. Each collar portion 14c is made of metal. Figure 2As shown, the collar portion 14c is a generally cylindrical shape extending axially. When a bolt (not shown) passes axially through the interior of each collar portion 14c and is screwed into the internal threaded hole (not shown) of the mounted body, each mounting portion 14 is fixed to the mounted body. That is, the electric oil pump 1 is fixed to the mounted body.

[0047] like Figure 1 As shown, the pump housing 16 is the lower part of the main housing 11. The pump housing 16 is a generally cylindrical shape extending axially about the rotation axis J. Figure 3 As shown, the downward-facing surface of the pump housing 16 is the lower end of the outer casing main body 11. The pump housing 16 has an opening 17c on the lower side, i.e., on the axial side (+Z side). The pump housing 16 houses the pump unit 60 inside. The pump housing 16 has a second side wall portion 16a and an annular wall portion 18. A receiving recess 17 is provided in the pump housing 16. That is, the outer casing main body 11 has a receiving recess 17.

[0048] The second sidewall portion 16a is a generally cylindrical shape extending axially around the rotation axis J. The second sidewall portion 16a radially surrounds the lower sides of both the pump portion 60 and the shaft 43. A pump cover 31 is fixed to the lower end of the second sidewall portion 16a. Figure 1 As shown, the outer diameter of the second sidewall portion 16a is smaller than the outer diameter of the first sidewall portion 12a. For example... Figure 3 As shown, a second protrusion 16c is provided on the second sidewall portion 16a. The second protrusion 16c is a protrusion that protrudes downward from the downward-facing surface of the second sidewall portion 16a. The second protrusion 16c extends circumferentially throughout the entire perimeter.

[0049] The receiving recess 17 is a hole that is recessed upward from the lower side of the pump receiving portion 16. That is, the receiving recess 17 is a hole that is recessed upward from the lower side of the outer casing body portion 11, i.e., the end on one axial side (+Z side), i.e., the other axial side (-Z side). The pump portion 60 is accommodated inside the receiving recess 17. The receiving recess 17 has an inner peripheral surface 17a and a top surface 17e. That is, the pump receiving portion 16 has a top surface 17e.

[0050] The inner circumferential surface 17a of the recess is the radially inward-facing surface of the inner surface that accommodates the recess 17. For example... Figure 4 As shown, the inner circumferential surface 17a of the recess is approximately circular in shape, surrounding the axis of rotation J. When viewed axially, the center of the inner circumferential surface 17a of the recess is offset from the axis of rotation J. Figure 3 As shown, the inner circumferential surface 17a of the recess is radially opposed to the pump portion 60. The inner circumferential surface 17a of the recess surrounds the pump portion 60 from the radially outer side. The lower end of the inner circumferential surface 17a of the recess is an opening 17c.

[0051] The top surface 17e is the downward-facing surface of the inner surface of the recess 17. The top surface 17e is the downward-facing surface of the annular wall portion 18. The top surface 17e is located above the pump portion 60, i.e., on the opposite side (-Z side) of the axial direction. The top surface 17e is axially opposed to the pump portion 60.

[0052] The annular wall portion 18 is approximately circular about the rotation axis J. The radially outer end of the annular wall portion 18 is connected to the inner circumferential surface of the second side wall portion 16a all the way around the periphery. The annular wall portion 18 is positioned lower than the motor portion 40 and higher than the pump portion 60. As described above, the downward-facing surface of the annular wall portion 18 is the top surface 17e. The annular wall portion 18 is provided with an inner cylinder portion 18a, a connecting hole portion 18c, an outlet hole 18e, a connecting groove portion 18g, and a first groove portion 19. Therefore, the outer casing body portion 11 has a connecting hole portion 18c. The connecting groove portion 18g and the first groove portion 19 are respectively provided on the top surface 17e.

[0053] The inner cylinder portion 18a protrudes upward from the radial inner edge of the annular wall portion 18. The inner cylinder portion 18a is generally cylindrical about the axis of rotation J. The inner circumferential surface of the inner cylinder portion 18a is axially connected to the inner circumferential surface of the annular wall portion 18.

[0054] The connecting hole 18c is a hole that axially penetrates both the annular wall portion 18 and the inner cylinder portion 18a. The connecting hole 18c is formed by the inner circumferential surface of the annular wall portion 18 and the inner circumferential surface of the inner cylinder portion 18a. When viewed axially, the connecting hole 18c is approximately circular about the rotation axis J. The connecting hole 18c connects the interior of the motor housing portion 12 with the interior of the housing recess 17. That is, the connecting hole 18c connects the interior of the motor housing portion 12 with the interior of the pump housing portion 16. The shaft 43 passes axially through the interior of the connecting hole 18c. The outlet hole 18e is a hole that axially penetrates the annular wall portion 18. The outlet hole 18e is located on the radially outer portion of the annular wall portion 18.

[0055] The first groove 19 is a groove recessed upward from the top surface 17e, that is, on the other side of the axial direction (-Z side). The first groove 19 opens on the lower side. In this embodiment, two first grooves 19 are provided on the top surface 17e. The two first grooves 19 include a first suction side groove 19a and a first discharge side groove 19c.

[0056] like Figure 4As shown, when viewed axially, the first suction-side groove 19a and the first discharge-side groove 19c are both approximately arc-shaped grooves extending circumferentially. That is, the first groove 19 is a groove extending circumferentially. The first suction-side groove 19a and the first discharge-side groove 19c are located at different positions circumferentially. The first suction-side groove 19a and the first discharge-side groove 19c are radially opposed. More specifically, the first suction-side groove 19a and the first discharge-side groove 19c are radially opposed across the rotation axis J. Figure 3 and Figure 4 As shown, when viewed axially, the first suction side groove 19a overlaps with the outlet hole 18e. Figure 3 As shown, the outlet hole 18e connects the interior of the motor housing 12 with the interior of the first suction side groove 19a.

[0057] The connecting groove 18g is a groove that is recessed upwards from the top surface 17e, that is, on the other side of the axial direction (-Z side). For example... Figure 4 As shown, the connecting groove 18g is a groove extending linearly in the radial direction. The radially inner end of the connecting groove 18g opens into the connecting hole 18c. In this embodiment, the radially outer end of the connecting groove 18g opens into the first discharge-side groove 19c. Thus, in this embodiment, the connecting groove 18g connects the connecting hole 18c to the first discharge-side groove 19c. That is, the connecting groove 18g connects the connecting hole 18c to the first groove 19. It should be noted that, alternatively, the radially inner end of the connecting groove 18g may open into the annular wall 18, and the radially outer end of the connecting groove 18g may open into the first suction-side groove 19a. In this case, the connecting groove 18g connects the connecting hole 18c to the first suction-side groove 19a. That is, the connecting groove 18g connects the connecting hole 18c to the first groove 19.

[0058] like Figure 1As shown, rib 20 is provided on the outer peripheral surface of the second sidewall portion 16a, that is, the radially outward surface of the pump housing portion 16. As described above, in this embodiment, the housing body portion 11 is made of resin. Therefore, compared with the case where the housing body portion 11 is made of metal, it is difficult to improve the strength of the housing body portion 11. In contrast, in this embodiment, by providing rib 20 on the radially outward surface of the pump housing portion 16, the strength of the housing body portion 11 can be appropriately improved. Rib 20 is a plate-shaped part that protrudes radially outward from the pump housing portion 16. The plate surface of rib 20 faces circumferentially. Rib 20 extends axially. The upper end of rib 20 is connected to the first sidewall portion 12a. That is, rib 20 is connected to the motor housing portion 12. The housing body portion 11 has a plurality of ribs 20. In this embodiment, the housing body portion 11 has four ribs 20. The number of ribs 20 in the housing body portion 11 can be three or less, or five or more. Each rib 20 is arranged at intervals along the circumferential direction. In this embodiment, the ribs 20 are arranged at approximately equal intervals along the circumferential direction. Therefore, the deviation in strength of the outer shell body 11 in the circumferential direction can be appropriately reduced. Figure 5 As shown, the plurality of ribs 20 includes a first rib 20a and a second rib 20c. In this embodiment, the plurality of ribs 20 includes one first rib 20a and three second ribs 20c. The number of first ribs 20a and the number of second ribs 20c included in the plurality of ribs 20 are not limited to this embodiment.

[0059] The first rib 20a and each of the second ribs 20c are respectively provided on the radially outward side of the pump housing 16. The first rib 20a and each of the second ribs 20c extend axially. The second ribs 20c and the first rib 20a are respectively arranged circumferentially spaced apart from each other. The lower side of the first rib 20a, that is, the axial side (+Z side), is located lower than the lower side of the respective ends of the multiple second ribs 20c.

[0060] like Figure 2 As shown, the cover 21 is a generally cylindrical shape that protrudes axially about the rotation axis J. The cover 21 has an opening on its lower side. The cover 21 is fixed to the upper end of the main body 11 of the outer casing. The cover 21 blocks the opening on the upper side of the motor housing 12. The internal space of the cover 21 is connected to the internal space of the motor housing 12. A control device 56 is housed inside the cover 21. In this embodiment, the cover 21 is made of resin. Polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), and polycarbonate (PC) can be used as the material constituting the cover 21. The cover 21 can also be made of other materials such as metal. The cover 21 has a peripheral wall portion 22 and a substrate cover portion 23.

[0061] The cover peripheral wall portion 22 is a generally cylindrical shape that protrudes axially about the rotation axis J. The cover peripheral wall portion 22 surrounds the control device 56 radially outward. A second annular groove portion 22a is provided in the cover peripheral wall portion 22. The second annular groove portion 22a is a groove that is recessed upward from the downward-facing surface of the cover peripheral wall portion 22 and extends circumferentially. The first protrusion 12e of the motor receiving portion 12 is inserted inside the second annular groove portion 22a. Therefore, the radial position of the cover portion 21 relative to the outer casing body portion 11 is determined. In this embodiment, the lower end of the cover peripheral wall portion 22 and the upper end of the first side wall portion 12a are joined together by welding circumferentially. Therefore, the outer casing body portion 11 and the cover portion 21 can be properly sealed, thereby appropriately improving the airtightness of the electric oil pump 1. Furthermore, there is no need to provide additional sealing components such as O-rings to seal between the main body 11 and the cover 21, thus suppressing the increase in the number of parts of the electric oil pump 1.

[0062] like Figure 1 As shown, the substrate cover 23 is a roughly circular plate centered on the rotation axis J. Figure 2 As shown, the substrate cover 23 is positioned above the control device 56. The radial outer edge of the substrate cover 23 is connected to the upper end of the cover peripheral wall 22.

[0063] like Figure 3 As shown, the pump cover 31 is approximately annular about the rotation axis J. The pump cover 31 is positioned below the pump section 60. The pump cover 31 is fixed to the lower end of the pump receiving section 16. The pump cover 31 covers the pump section 60 from below. The pump cover 31 blocks the receiving recess 17 from below, i.e., on the axial side (+Z side). That is, the pump cover 31 blocks the opening 17c from below. In this embodiment, the pump cover 31 is made of resin. Polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), and polycarbonate (PC) can be used as the material constituting the pump cover 31. The pump cover 31 can also be made of other materials such as metal. In this embodiment, the pump cover 31 is formed by molding the base plate portion 37 as an insert for the embedded member. Therefore, the base plate portion 37 is fixed to the pump cover 31. Therefore, in the assembly process of the electric oil pump 1, for example, it is not necessary to fix the base plate 37 to the pump cover 31 with adhesive, thus the increase in assembly time of the electric oil pump 1 can be more appropriately suppressed. The pump cover 31 has a cover body 32 and a protruding cylinder 35.

[0064] The main body 32 is the upper part of the pump cover 31. The main body 32 is approximately annular about the axis of rotation J. The main body 32 includes an inlet 32a, a discharge hole 32b, a discharge outlet 32c, a third annular groove 32e, and a second groove 33. That is, the pump cover 31 has a second groove 33. Figure 5 As shown, a protrusion 34 is provided in the main body 32 of the cover. That is, a protrusion 34 is provided in the pump cover 31.

[0065] like Figure 3 As shown, the suction port 32a is an opening on the downward-facing surface of the main body 32. The suction port 32a opens on the lower side. Although not shown in the figure, when viewed axially, the suction port 32a is an arc shape extending circumferentially. As described later, the suction port 32a is connected to the second suction-side groove 33a. Oil from outside the electric oil pump 1 is drawn into the interior of the housing 10 via the suction port 32a.

[0066] The discharge hole 32b is a hole extending radially inward from the radially outward surface of the cover body 32. As described later, the radially inward end of the discharge hole 32b is connected to the second discharge side groove 33c. Figure 1 As shown, the discharge port 32b opens radially outward. The discharge outlet 32c is an opening located at the radially outward end of the discharge port 32b. The discharge outlet 32c is provided on the radially outward-facing surface of the pump cover 31. Figure 3 As shown, the oil compressed in the pump section 60 is discharged to the outside of the electric oil pump 1 through the discharge port 32b and the discharge outlet 32c.

[0067] The third annular groove 32e is a groove that is recessed downward from the upper surface of the cover body 32 and extends circumferentially. The second protrusion 16c of the pump housing 16 is inserted inside the third annular groove 32e. Therefore, the radial position of the pump cover 31 relative to the outer casing body 11 is determined. In this embodiment, the lower end of the second sidewall portion 16a and the upper end of the cover body 32 are circumferentially joined together by welding. That is, the pump housing 16 and the pump cover 31 are circumferentially joined together by welding. Therefore, the outer casing body 11 and the pump cover 31 can be properly sealed, thus appropriately improving the airtightness of the electric oil pump 1. Furthermore, it is not necessary to separately provide sealing members such as O-rings to seal the outer casing body 11 and the pump cover 31, thus suppressing an increase in the number of parts in the electric oil pump 1.

[0068] The second groove 33 is a groove that is recessed downward from the upward-facing surface of the cover body 32. For example... Figure 6 As shown, the second groove 33 extends circumferentially. That is, a second groove 33 is provided on the upward-facing side of the pump cover 31, i.e., the other axial side (-Z side), which is recessed on the downward-facing side, i.e., the axial side (+Z side) and extends circumferentially. Figure 3 As shown, the second groove 33 opens upwards. In this embodiment, two second grooves 33 are provided on the main body 32 of the cover. That is, two second grooves 33 are provided on the pump cover 31. The two second grooves 33 include a second suction side groove 33a and a second discharge side groove 33c.

[0069] like Figure 6As shown, when viewed axially, the second suction-side groove 33a and the second discharge-side groove 33c are both arc-shaped grooves extending circumferentially. That is, the second groove 33 is a groove extending circumferentially. The second suction-side groove 33a and the second discharge-side groove 33c are located at different positions in the circumferential direction. The second suction-side groove 33a and the second discharge-side groove 33c are radially opposed. That is, the two second grooves 33 are radially opposed. More specifically, the second suction-side groove 33a and the second discharge-side groove 33c are radially opposed across the rotation axis J.

[0070] like Figure 6 As shown, when viewed axially, the second suction-side groove 33a overlaps with the suction port 32a. The interior of the second suction-side groove 33a is connected to the suction port 32a. When viewed axially, the second suction-side groove 33a overlaps with the first suction-side groove 19a. Figure 4 and Figure 6 As shown, when viewed from the axial direction, the second suction side groove 33a and the first suction side groove 19a have approximately the same shape.

[0071] like Figure 3 As shown, the second discharge side groove 33c is connected to the discharge hole 32b. Therefore, the interior of the second discharge side groove 33c is connected to the discharge outlet 32c via the discharge hole 32b. When viewed axially, the second discharge side groove 33c overlaps with the first discharge side groove 19c. Figure 4 and Figure 6 As shown, when viewed from the axial direction, the second discharge side groove 33c and the first discharge side groove 19c have approximately the same shape.

[0072] like Figure 5 and Figure 6 As shown, the protrusion 34 protrudes radially outward from the upper end of the radially outward-facing surface of the cover body 32. Viewed axially, the protrusion 34 has a generally trapezoidal shape with its longer side radially inward and its shorter side radially outward. Viewed axially, the protrusion 34 overlaps with the first rib 20a. A positioning portion 34a is provided in the protrusion 34.

[0073] The positioning portion 34a is a hole recessed from the upper side (the other side of the axial direction, i.e., the -Z side) of the protrusion 34 towards the lower side (the +Z side of the axial direction). In this embodiment, the positioning portion 34a penetrates the protrusion 34 axially. The positioning portion 34a may also not penetrate the protrusion 34 axially. For example... Figure 6 As shown, in this embodiment, the positioning portion 34a opens radially outward. That is, the positioning portion 34a opens radially upward. The positioning portion 34a may also not open radially. For example... Figure 5As shown, a portion of the first rib 20a on one axial side is located inside the positioning portion 34a. In this embodiment, the positioning portion 34a engages with the first rib 20a. Therefore, the circumferential positional accuracy of the pump cover 31 relative to the outer casing body 11 can be improved.

[0074] like Figure 3 As shown, the protruding cylindrical portion 35 protrudes downward from the lower end of the cover body portion 32. The protruding cylindrical portion 35 is generally cylindrical and extends axially about the rotation axis J. A fourth annular groove portion 35a is provided in the protruding cylindrical portion 35. The fourth annular groove portion 35a is a groove that is recessed radially inward from the radially outward surface of the protruding cylindrical portion 35 and extends circumferentially. The fourth annular groove portion 35a extends all around the circumference. An O-ring 92 is embedded inside the fourth annular groove portion 35a.

[0075] The metal outer casing 25 is housed inside the outer casing main body 11. As described above, the metal outer casing 25 is fixed to the outer casing main body 11. As described above, at least a portion of the metal outer casing 25 is embedded in the outer casing main body 11. In this embodiment, the metal outer casing 25 is made of metal. Aluminum and stainless steel, etc., can be used as materials constituting the metal outer casing 25. As described above, in this embodiment, the outer casing main body 11 is made of resin. Therefore, the coefficient of linear expansion of the metal outer casing 25 is smaller than that of the outer casing main body 11. Figure 7 As shown, the metal outer casing 25 has a peripheral wall portion 26, a top wall portion 27, and a cylindrical portion 29.

[0076] The peripheral wall portion 26 is a cylindrical shape extending axially. More specifically, the peripheral wall portion 26 is a generally cylindrical shape surrounding the axis of rotation J. Figure 4 As shown, when viewed axially, the center of the peripheral wall portion 26 is approximately aligned with the center of the inner peripheral surface 17a of the recess. Figure 3 As shown, the peripheral wall portion 26 has an opening on its lower side. The peripheral wall portion 26 is disposed inside the receiving recess 17. The peripheral wall portion 26 is fixed to the inner peripheral surface 17a of the recess. The radially outer portion of the peripheral wall portion 26 is embedded inside the second side wall portion 16a. The peripheral wall portion 26 surrounds the pump portion 60 from the radially outer side. Radially, the peripheral wall portion 26 is disposed between the pump portion 60 and the inner peripheral surface 17a of the recess. The upper end of the peripheral wall portion 26 contacts the top surface 17e. Axially, the lower end of the peripheral wall portion 26 is at approximately the same position as the lower end of the pump receiving portion 16.

[0077] like Figure 7As shown, the top wall portion 27 is a generally annular plate extending radially. The top wall portion 27 is a plate extending radially outward from the lower side of the cylindrical portion 29, i.e., the end on the axial side (+Z side). The top wall portion 27 surrounds the rotation axis J. The upper side of the peripheral wall portion 26, i.e., the end on the other axial side (-Z side), is circumferentially connected to the radially outward end of the top wall portion 27. Therefore, in this embodiment, the peripheral wall portion 26 and the top wall portion 27 are integrally formed, thus reducing the number of parts in the metal housing portion 25 compared to a case where the peripheral wall portion 26 and the top wall portion 27 are separate components. Therefore, the increase in manufacturing time for the electric oil pump 1 can be suppressed.

[0078] like Figure 3 As shown, the top wall portion 27 is disposed inside the receiving recess 17. That is, the top wall portion 27 is disposed inside the pump receiving portion 16. The upper portion of the top wall portion 27 is embedded inside the annular wall portion 18. The top wall portion 27 is fixed to the top surface 17e. The top surface 17e is located above the top wall portion 27 and is axially opposed to the top wall portion 27. The downward-facing surface of the top wall portion 27 is located below the top surface 17e. Axially, the top wall portion 27 is disposed between the pump portion 60 and the top surface 17e. Figure 7 As shown, a first through hole 28 and a second cutout 27a are provided in the top wall portion 27.

[0079] The first through hole 28 is a hole that penetrates the top wall portion 27 in the axial direction. In this embodiment, two first through holes 28 are provided in the top wall portion 27. The two first through holes 28 include a first suction-side through hole 28a and a first discharge-side through hole 28c.

[0080] Viewed axially, the first intake-side through hole 28a and the first discharge-side through hole 28c are both approximately arc-shaped, extending circumferentially. That is, the first through hole 28 is a hole extending circumferentially. The first intake-side through hole 28a and the first discharge-side through hole 28c are located at different positions circumferentially. The first intake-side through hole 28a and the first discharge-side through hole 28c are radially opposed. More specifically, the first intake-side through hole 28a and the first discharge-side through hole 28c are radially opposed across the rotation axis J.

[0081] like Figure 4 As shown, when viewed axially, the first suction-side through hole 28a surrounds the first suction-side groove 19a. Therefore, at least a portion of the first suction-side through hole 28a overlaps with the first suction-side groove 19a. That is, at least a portion of the first through hole 28a overlaps with the first groove 19a. Therefore, as... Figure 3 As shown, the interior of the first suction-side groove 19a is connected to the interior of the receiving recess 17 via the first suction-side through hole 28a. Furthermore, a portion of the top surface 17e is exposed on the lower side via the first suction-side through hole 28a.

[0082] like Figure 4 As shown, when viewed axially, the first discharge-side through hole 28c surrounds the first discharge-side groove 19c. Therefore, at least a portion of the first discharge-side through hole 28c overlaps with the first discharge-side groove 19c. That is, at least a portion of the first through hole 28c overlaps with the first groove 19c. Therefore, as... Figure 3 As shown, the interior of the first discharge-side groove 19c is connected to the interior of the receiving recess 17 via the first discharge-side through hole 28c. As described above, the interior of the first suction-side groove 19a is connected to the interior of the receiving recess 17 via the first suction-side through hole 28a. Thus, the interior of the first groove 19a is connected to the interior of the receiving recess 17 via the first through hole 28. Furthermore, a portion of the top surface 17e is exposed on its lower side via the first discharge-side through hole 28c.

[0083] like Figure 7 As shown, the second cut 27a is a cut that penetrates the top wall portion 27 axially. The second cut 27a extends radially. In this embodiment, one end of the second cut 27a, which is the radially outer end, is connected to the first discharge-side through hole 28c. That is, one end of the second cut 27a is connected to the first through hole 28c. It should be noted that the radially outer end of the second cut 27a may also be connected to the first suction-side through hole 28a. The other end of the second cut 27a, which is the radially inner end, reaches the radially inner edge of the top wall portion 27. Therefore, the second cut 27a opens radially inward. Figure 3 and Figure 4 As shown, when viewed axially, at least a portion of the communicating groove 18g of the annular wall portion 18 overlaps with the second cutout portion 27a. Therefore, the interior of the receiving recess 17 is connected to the interior of the communicating groove 18g via the second cutout portion 27a.

[0084] like Figure 7 As shown, the cylindrical portion 29 is a cylindrical shape extending upward from the radial inner edge of the top wall portion 27, that is, on the other side of the axial direction (-Z side). More specifically, the top wall portion 27 is a generally cylindrical shape extending axially about the rotation axis J. Figure 3 As shown, the cylindrical portion 29 is disposed inside the connecting hole portion 18c. The shaft 43 passes through the interior of the cylindrical portion 29 axially. Radially, the cylindrical portion 29 is disposed between the shaft 43 and the inner circumferential surface of the connecting hole portion 18c. The cylindrical portion 29 supports the shaft 43 so that it can rotate about the rotation axis J. Therefore, direct contact between the shaft 43 and the resin-made connecting hole portion 18c can be suppressed, thus suppressing wear of the connecting hole portion 18c when the electric oil pump 1 is operated. Figure 7 As shown, a first cutout 29a is provided in the cylindrical portion 29.

[0085] The first cut 29a is a radial cut that penetrates a portion of the circumferential portion of the cylindrical portion 29. The first cut 29a extends axially. The lower end of the first cut 29a reaches the lower end of the cylindrical portion 29. Therefore, the first cut 29a opens downward, that is, on the axial side (+Z side). Therefore, as... Figure 3 As shown, the interior of the cylindrical portion 29 is connected to the interior of the receiving recess 17 via the first cutout 29a. That is, the interior of the cylindrical portion 29 is connected to the interior of the pump receiving portion 16 via the first cutout 29a.

[0086] like Figure 7 As shown, the other end of the radially inner end of the second cutout 27a is connected to the lower end of the first cutout 29a. As described above, one end of the second cutout 27a is connected to the first discharge-side through hole 28c. Furthermore, as described above, the interior of the first discharge-side groove 19c is connected to the interior of the receiving recess 17 via the first discharge-side through hole 28c. Thus, as... Figure 3 As shown, the interior of the cylindrical portion 29 is connected to the interior of the first discharge side groove portion 19c and the interior of the receiving recess 17 via the second cut portion 27a and the first cut portion 29a. Furthermore, as... Figure 4 As shown, the interior of the first cutout 29a is connected to the interior of the connecting groove 18g. As described above, the connecting groove 18g connects the connecting hole 18c to the first discharge side groove 19c. Therefore, as... Figure 3 As shown, the interior of the cylindrical portion 29 is connected to the interior of the first discharge side groove 19c and the interior of the receiving recess 17 via the second cut portion 27a, the connecting groove portion 18g and the first cut portion 29a.

[0087] like Figure 8 As shown, the base plate 37 is a roughly annular plate that extends radially. The base plate 37 surrounds the axis of rotation J. Figure 3 As shown, the base plate 37 is fixed to the upward-facing surface of the pump housing 31, i.e., the opposite side (-Z side) axially. The base plate 37 is positioned lower than the pump portion 60. The base plate 37 and the pump portion 60 are axially opposed. In this embodiment, the base plate 37 contacts the peripheral wall portion 26 of the metal housing portion 25 axially. Therefore, direct contact between the inner rotor 61 and the outer rotor 62 and the resin pump housing 31 can be prevented. The base plate 37 may also be axially spaced apart from the peripheral wall portion 26. The radially outer end of the base plate 37 is located radially outer than the peripheral wall portion 26. In this embodiment, the base plate 37 is made of metal. Aluminum and stainless steel, etc., can be used as the material constituting the base plate 37. Figure 8 As shown, the base plate 37 is provided with multiple holes 37a and a second through hole 38.

[0088] Each hole 37a is an axially penetrating hole through the base plate portion 37. In this embodiment, six holes 37a are provided in the base plate portion. The holes 37a are arranged at approximately equal intervals along the circumferential direction. Although not shown in the figure, a portion of the pump cover 31 enters the interior of each hole 37a. Therefore, the radial and circumferential positional variations of the base plate portion 37 relative to the pump cover 31 can be appropriately suppressed, and the holding force of the pump cover 31 in retaining the base plate portion 37 can be improved.

[0089] The second through hole 38 is a hole that penetrates the bottom plate portion 37 in the axial direction. In this embodiment, two second through holes 38 are provided in the bottom plate portion 37. The two second through holes 38 include a second suction-side through hole 38a and a second discharge-side through hole 38c.

[0090] Viewed axially, the second intake-side through hole 38a and the second discharge-side through hole 38c are both approximately arc-shaped extending circumferentially. That is, the second through hole 38 is a hole extending circumferentially. The second intake-side through hole 38a and the second discharge-side through hole 38c are located at different positions circumferentially. The second intake-side through hole 38a and the second discharge-side through hole 38c are radially opposed. More specifically, the second intake-side through hole 38a and the second discharge-side through hole 38c are radially opposed across the rotation axis J.

[0091] like Figure 6 As shown, when viewed axially, the second suction-side through hole 38a surrounds the second suction-side groove 33a. Therefore, at least a portion of the second suction-side through hole 38a overlaps with the second suction-side groove 33a. That is, at least a portion of the second through hole 38a overlaps with the second groove 33a. Therefore, as... Figure 3 As shown, the interior of the second suction side groove 33a is connected to the interior of the receiving recess 17 via the second suction side through hole 38a.

[0092] like Figure 6 As shown, when viewed axially, the second discharge-side through hole 38c surrounds the second discharge-side groove 33c. Therefore, at least a portion of the second discharge-side through hole 38c overlaps with the second discharge-side groove 33c. That is, at least a portion of the second through hole 38c overlaps with the second groove 33c. Therefore, as... Figure 3 As shown, the interior of the second discharge-side groove 33c is connected to the interior of the receiving recess 17 via the second discharge-side through hole 38c. As described above, the interior of the second suction-side groove 33a is connected to the interior of the receiving recess 17 via the second suction-side through hole 38a. Therefore, the interior of the second groove 33 is connected to the interior of the receiving recess 17 via the second through hole 38.

[0093] like Figure 2As shown, the motor unit 40 is housed inside the housing body 11. More specifically, the motor unit 40 is housed inside the motor housing 12. Axially, the motor unit 40 is positioned below the control device 56 and above the pump unit 60. The motor unit 40 has a rotor 41 and a stator 50.

[0094] The rotor 41 is rotatable. In this embodiment, the rotor 41 is rotatable about the rotation axis J. The rotor 41 may also be rotatable about an imaginary axis extending axially, different from the rotation axis J. The rotor 41 has a rotor core 41a and a magnet 41b. The rotor core 41a is approximately annular about the rotation axis J. The magnet 41b is fixed to the rotor core 41a.

[0095] The stator 50 is disposed radially outward from the rotor 41. The stator 50 and the rotor 41 are radially opposed by a gap. As described above, in this embodiment, the stator 50 is embedded inside the stator holding portion 12g. Therefore, the outer casing body portion 11 holds the stator 50. The stator 50 has a stator core 51, an insulator 52, and a coil portion 53.

[0096] The stator core 51 surrounds the rotor core 41a radially outward. The stator core 51 has a generally annular core back 51a and a plurality of teeth 51b protruding radially inward from the inner circumferential surface of the core back 51a. Although not shown in the figure, the plurality of teeth 51b are arranged at intervals along the circumference. A coil portion 53 is mounted on the teeth 51b through an insulating member 52. The coil portion 53 is composed of wound coil wire. Although not shown in the figure, the coil portion 53 is electrically connected to a control device 56. Current is supplied from the control device 56 to the coil portion 53.

[0097] Shaft 43 is a generally cylindrical shape extending axially. In this embodiment, shaft 43 is a generally cylindrical shape extending axially about the rotation axis J. Shaft 43 may also extend axially about an imaginary axis extending axially, different from the rotation axis J. Shaft 43 extends across motor housing 12 and pump housing 16. The upper portion of shaft 43 is disposed inside motor housing 12. The upper portion of shaft 43 passes axially through the interior of rotor core 41a. Rotor core 41a is fixed to the outer circumferential surface of shaft 43. That is, rotor 41 is fixed to shaft 43. Therefore, shaft 43 can rotate together with rotor 41. The axially central portion of shaft 43 passes axially through the interior of the communication hole 18c of housing body 11 and the interior of the cylindrical portion 29 of metal housing 25. As described above, cylindrical portion 29 is disposed between shaft 43 and the inner circumferential surface of communication hole 18c. The shaft 43 is supported by the cylindrical portion 29 so that it can rotate about the rotation axis J. The lower part of the shaft 43 is disposed inside the pump housing 16. The lower part of the shaft 43 is connected to the pump section 60. Thus, the rotational torque of the rotor 41 is transmitted to the pump section 60 via the shaft 43.

[0098] The control device 56 generates and supplies current to the coil section 53. Therefore, the control device 56 controls the operation of the electric oil pump 1. The control device 56 has a circuit board 57.

[0099] The circuit board 57 is a plate-shaped structure extending in a direction orthogonal to the axial direction. The circuit board 57 is held in multiple board holding portions 12h within the main body 11 of the housing. Multiple electronic components are mounted on the circuit board 57. These components include multiple power semiconductor devices such as insulated-gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs), multiple capacitors, and multiple resistors. The circuit board 57 is electrically connected to an external power supply (not shown) and a coil section 53, respectively. The circuit board 57 generates a current with a predetermined waveform based on the current supplied by the external power supply and supplies this current to the coil section 53. When current is supplied to the coil section 53, the rotor 41 and the shaft 43 rotate around the rotation axis J.

[0100] The pump section 60 is housed inside the main housing section 11. More specifically, the pump section 60 is housed inside the pump housing section 16. Furthermore, the pump section 60 is housed inside the metal housing section 25. As described above, the peripheral wall section 26 surrounds the pump section 60 radially outward. The top wall section 27 is axially opposed to the pump section 60. The pump section 60 is connected to the lower side of the shaft 43, i.e., the axial side (+Z side). The pump section 60 is driven by the power of the motor section 40 to draw oil from the outside of the electric oil pump 1, compresses the drawn oil, and discharges it to the outside of the electric oil pump 1. The pump section 60 is driven by the power of the motor section 40 to pressurize and deliver oil. The pump section 60 of this embodiment is a cycloidal pump. That is, the electric oil pump 1 of this embodiment is a positive displacement electric oil pump. In this embodiment, the pump section 60 is made of metal. The pump section 60 has an inner rotor 61 and an outer rotor 62.

[0101] The inner rotor 61 extends axially and is annular when viewed axially. The lower portion of the shaft 43 is inserted inside 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 connected to the lower side of the shaft 43, i.e., the axial side (+Z side). The power of the rotor 41 is transmitted to the inner rotor 61. Therefore, the inner rotor 61 can rotate about the rotation axis J. Furthermore, the inner circumferential surface of the inner rotor 61 and the shaft 43 do not need to be firmly fixed. Flat portions can be machined on both the inner circumferential surface (inner diameter) of the inner rotor 61 and the outer diameter of the shaft 43. The flat portion of the inner circumferential surface (inner diameter) of the inner rotor 61 can be aligned with the flat portion of the outer diameter of the shaft 43, allowing the inner circumferential surface (inner diameter) of the inner rotor 61 to be inserted into the shaft 43 with a clearance fit. This configuration facilitates the assembly of the inner rotor 61 and the shaft 43 and enables the transmission of power from the rotor 41 to the inner rotor 61. Furthermore, by using a stop ring, the axial relative positional offset between the inner rotor 61 and the shaft 43 can be suppressed.

[0102] The outer rotor 62 is positioned radially outward from the inner rotor 61. The outer rotor 62 is annular, surrounding the inner rotor 61 radially outward. A gap is provided between the outer rotor 62 and the peripheral wall portion 26. The outer peripheral surface of the outer rotor 62 can partially contact the inner peripheral surface of the peripheral wall portion 26. When the electric oil pump 1 is operated, oil is trapped between the outer rotor 62 and the peripheral wall portion 26.

[0103] like Figure 9 As shown, the inner rotor 61 and the outer rotor 62 each have cycloidal tooth profiles. The inner rotor 61 has multiple external teeth 61a protruding radially outward. The outer rotor 62 has multiple internal teeth 62a protruding radially inward and meshing 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 slides on the inner circumferential surface of the peripheral wall portion 26 while rotating eccentrically about the rotation axis J.

[0104] like Figure 3As shown, the interior of the second suction-side groove 33a and the interior of the first suction-side groove 19a are axially connected via the 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. In the following description, the internal space of the interconnected second suction-side groove 33a, the gap G, and the first suction-side groove 19a are referred to as suction chamber A1. Suction chamber A1 is connected to suction port 32a.

[0105] The interior of the second discharge side groove 33c is axially connected to the interior of the first discharge side groove 19c 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 interconnected second discharge side groove 33c, the gap G, and the internal space of the first discharge side groove 19c are referred to as compression chamber A2. Compression chamber A2 is connected to discharge outlet 32c via discharge hole 32b.

[0106] When the electric oil pump 1 operates, the gap G between the inner rotor 61 and the outer rotor 62 moves around the rotation axis J due to the rotation of the inner rotor 61 and the outer rotor 62. Therefore, when the pressure in the suction chamber A1 decreases, as... Figure 3 As indicated by arrow F1, oil flows into the suction chamber A1 through the suction port 32a. More specifically, although not shown in the diagram, the oil flowing into the second suction-side groove 33a through the suction port 32a flows circumferentially inside the second suction-side groove 33a and is drawn into the gap G through the second suction-side through hole 38a. A portion of the oil drawn into the gap G flows into the first suction-side groove 19a through the first suction-side through hole 28a. The oil flowing into the first suction-side groove 19a flows circumferentially inside the first suction-side groove 19a and is again drawn into the gap G.

[0107] When the gap G moves circumferentially due to the rotation of the inner rotor 61 and the outer rotor 62, as... Figure 3As indicated by arrow F2, oil moves from the suction chamber A1 to the compression chamber A2. Although not shown in the diagram, a portion of the oil drawn into gap G flows into the first discharge side groove 19c via the first discharge side through hole 28c. As described above, a portion of the oil drawn in from the suction port 32a flows into the first suction side groove 19a via the first suction side through hole 28a. Thus, the oil pumped by the pump section 60 passes through the first through hole 28. The oil flowing into the first discharge side groove 19c flows circumferentially inside the first discharge side groove 19c and is again drawn into gap G. As described above, the oil flowing into the first suction side groove 19a flows circumferentially inside the first suction side groove 19a. Thus, the oil pumped by the pump section 60 flows into the interior of the first groove 19. The oil drawn into gap G flows into the second discharge side groove 33c via the second discharge side through hole 38c. The oil flowing into the second discharge side groove 33c flows circumferentially inside the second discharge side groove 33c. Therefore, when the pressure of the oil in compression chamber A2 increases, such as Figure 3 As indicated by arrow F3, the oil in compression chamber A2 is pumped to the outside of electric oil pump 1 via discharge port 32b and discharge outlet 32c. Therefore, electric oil pump 1 supplies oil to the mounted body (not shown).

[0108] As described above, in this embodiment, oil flows into the interiors of the first suction-side groove 19a and the second suction-side groove 33a in the suction chamber A1. Therefore, a downward force from the oil inside the first suction-side groove 19a and an upward force from the oil inside the second suction-side groove 33a are applied to the pump unit 60. Furthermore, in this embodiment, oil flows into the interiors of the first discharge-side groove 19c and the second discharge-side groove 33c in the compression chamber A2. Therefore, a downward force from the oil inside the first discharge-side groove 19c and an upward force from the oil inside the second discharge-side groove 33c are applied to the pump unit 60. That is, a downward force from the oil inside the first groove 19c and an upward force from the oil inside the second groove 33c are applied to the pump unit 60. Therefore, in this embodiment, the pump unit 60 can be rotated while oil forces are applied to it from both axial sides. Therefore, when the electric oil pump 1 is activated, it can suppress the vibration of the inner rotor 61 and the outer rotor 62.

[0109] As described above, the interior of the cylindrical portion 29 is connected to the interior of the pump receiving portion 16 via the first cutout portion 29a. Furthermore, as described above, the interior of the cylindrical portion 29 is connected to the interior of the first discharge side groove portion 19c and the interior of the receiving recess 17 via the second cutout portion 27a, the communicating groove portion 18g, and the first cutout portion 29a. Therefore, as... Figure 3As indicated by arrow F4, a portion of the oil drawn into the gap G and a portion of the oil inside the first discharge side groove 19c flow into the interior of the cylindrical portion 29, flowing upwards between the shaft 43 and the cylindrical portion 29. Therefore, oil can be supplied between the shaft 43 and the cylindrical portion 29. Thus, the shaft 43 and the cylindrical portion 29 can be properly lubricated by the oil, thereby reducing the friction between the shaft 43 and the cylindrical portion 29. Figure 3 As indicated by arrow F4, oil flowing upward between shaft 43 and cylindrical portion 29 flows into motor housing 12. Therefore, oil can be supplied to the interior of motor housing 12.

[0110] As described above, in this embodiment, the second cutout 27a and the connecting groove 18g are respectively connected to the first discharge side groove 19c. Furthermore, as described above, the oil pressure in the compression chamber A2 is high. Therefore, in this embodiment, the flow rate of oil flowing from the first discharge side groove 19c into the cylindrical portion 29 can be increased. Thus, the shaft 43 and the cylindrical portion 29 can be properly lubricated with oil, and the amount of oil flowing into the motor housing 12 can be increased. It should be noted that the second cutout 27a and the connecting groove 18g can also be connected to the first suction side groove 19a. In this case, oil can also flow from the first suction side groove 19a into the cylindrical portion 29, thus lubricating the shaft 43 and the cylindrical portion 29 with oil, and supplying oil to the motor housing 12. That is, the first groove 19 is connected to the second cut 27a and the connecting groove 18g respectively, so that the shaft 43 and the cylindrical part 29 can be lubricated by oil, and oil can be supplied to the motor housing 12.

[0111] The oil flowing into the motor housing 12 circulates within the motor housing 12 due to the rotation of the rotor 41, cooling both the motor unit 40 and the control device 56. Therefore, it prevents the temperatures of the motor unit 40 and the control device 56 from becoming excessively high, thereby improving the stability of their operation.

[0112] As described above, the outlet hole 18e connects the interior of the motor housing 12 to the interior of the first suction side groove 19a. Therefore, when the electric oil pump 1 operates, when the pressure in the suction chamber A1 decreases, as... Figure 3 As indicated by arrow F5, a portion of the oil circulating inside the motor housing 12 flows into the first suction side groove 19a via the outlet 18e. The oil flowing into the first suction side groove 19a, together with the oil flowing into the suction chamber A1 from the suction port 32a, is pumped to the outside of the electric oil pump 1 via the outlet 32c.

[0113] According to this embodiment, the electric oil pump 1 includes: a motor unit 40 having an axially extending shaft 43, a rotor 41 fixed to the shaft 43 and rotatable, and a stator 50 radially spaced apart from the rotor 41; a pump unit 60 driven by the power of the motor unit 40 to pressurize and pump oil; and a housing 10 housing the motor unit 40 and the pump unit 60. The pump unit 60 includes: an inner rotor 61 connected to the lower side of the shaft 43, i.e., the axial side (+Z side), and having external teeth 61a; and an outer rotor 62 surrounding the inner rotor 61 from the radially outer side and having internal teeth 62 that mesh with the external teeth 61a. a. The outer casing 10 has a resin-made outer casing body 11 and a metal-made metal outer casing 25. The outer casing body 11 has: a receiving recess 17 recessed from the lower end upwards, i.e., the other side (-Z side) axially, and internally accommodating the pump part 60; and a stator retaining part 12g that retains the stator 50. The receiving recess 17 has an inner peripheral surface 17a that surrounds the pump part 60 radially outwards. At least a portion of the metal outer casing 25 is embedded in the outer casing body 11. The metal outer casing 25 has a cylindrical peripheral wall portion 26 radially disposed between the pump part 60 and the inner peripheral surface 17a of the recess. In this embodiment, the outer casing body 11 is made of resin, thus reducing the volume of metal material constituting the outer casing 10 compared to the case where the outer casing body 11 is made of metal. Furthermore, since the outer casing body 11 is made of resin, the manufacturing cost of the outer casing 10 can be appropriately reduced. Furthermore, in this embodiment, the main body 11 holds the stator 50 and the metal housing 25, respectively, and at least a portion of the metal housing 25 is embedded in the main body 11. Therefore, in this embodiment, even with temperature variations in the electric oil pump 1, the reduction in positional accuracy between the central axis of the stator 50 and the central axis of the metal housing 25 can be more appropriately suppressed. Consequently, even with temperature variations in the electric oil pump 1, the reduction in positional accuracy between the central axis of the motor 40 and the central axis of the pump 60 can be appropriately suppressed. Therefore, the loss of driving force transmitted from the motor 40 to the pump 60 via the shaft 43 can be appropriately reduced. Therefore, the electric oil pump 1 can be made lighter, and the reduction in the flow rate of oil discharged from the pump 60 can be suppressed.

[0114] When the outer casing body 11 is made of resin, the thermal expansion of the outer casing body 11 when the electric oil pump 1 heats up is greater than that of the pump section 60. Therefore, if the electric oil pump 1 heats up, the radial gap between the inner peripheral surface 17a of the recess and the pump section 60 increases. In contrast, in this embodiment, as described above, a metal peripheral wall portion 26 is disposed radially between the pump section 60 and the inner peripheral surface 17a of the recess, so even if the electric oil pump 1 heats up, the increase in the radial gap between the pump section 60 and the peripheral wall portion 26 can be suppressed. Therefore, oil leakage between the pump section 60 and the peripheral wall portion 26 can be suppressed. Therefore, the electric oil pump 1 can be made lighter, and the decrease in the flow rate of oil discharged from the pump section 60 can be suppressed.

[0115] In this embodiment, as described above, the outer casing body 11 is made of resin. Therefore, due to shrinkage after molding, the dimensional deviation of the outer casing body 11 is prone to increase. Therefore, to avoid interference between the inner surface of the receiving recess 17 and the pump section 60, the difference between the dimensions of the receiving recess 17 and the pump section 60 needs to be designed to be large. Therefore, the radial gap between the pump section 60 and the inner peripheral surface 17a of the recess is prone to increase. Therefore, when the outer casing 10 does not have a metal outer casing portion 25, the amount of oil leaking between the pump section 60 and the inner peripheral surface 17a of the recess is prone to increase, and the flow rate discharged from the pump section 60 is prone to decrease. In contrast, in this embodiment, as described above, a metal peripheral wall portion 26 is disposed radially between the pump section 60 and the inner peripheral surface 17a of the recess, thus suppressing oil leakage between the pump section 60 and the peripheral wall portion 26. Therefore, the electric oil pump 1 can be made lighter, and the decrease in the flow rate of oil discharged from the pump section 60 can be appropriately suppressed.

[0116] In this embodiment, as described above, a metal peripheral wall portion 26 is disposed radially between the pump portion 60 and the inner peripheral surface 17a of the recess, thereby preventing direct contact between the outer rotor 62 and the resin inner peripheral surface 17a of the recess. Therefore, when the electric oil pump 1 operates, wear of the inner peripheral surface 17a of the recess due to friction with the outer rotor 62 can be suppressed. Thus, the durability of the electric oil pump 1 can be improved.

[0117] According to this embodiment, the receiving recess 17 has a top surface 17e located above the pump section 60, i.e., on the opposite side (-Z side) axially, and axially opposite to the pump section 60. The metal housing section 25 has a top wall section 27 axially disposed between the pump section 60 and the top surface 17e. Therefore, direct contact between the inner rotor 61 and the outer rotor 62 and the resin-made top surface 17e can be suppressed. Therefore, when the electric oil pump 1 is operating, wear 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 improved more appropriately.

[0118] According to this embodiment, the upper end of the peripheral wall portion 26, i.e., the other axial side (-Z side), is connected to the radially outer end of the top wall portion 27 all around the circumference. Therefore, oil leakage from between the peripheral wall portion 26 and the top wall portion 27 to the outside of the metal housing portion 25 can be appropriately suppressed. Therefore, oil leakage between the peripheral wall portion 26 and the inner peripheral surface 17a of the recess can be suppressed, and thus the decrease in the flow rate of oil discharged from the pump portion 60 can be more appropriately suppressed.

[0119] According to this embodiment, a first through hole 28 is provided in the top wall portion 27, extending axially through the top wall portion 27. The downward-facing surface of the top wall portion 27, i.e., the axial side (+Z side), is located lower than the top surface 17e. Therefore, direct contact between the inner rotor 61 and the outer rotor 62 and the resin-made top surface 17e via the first through hole 28 can be suppressed. Therefore, when the electric oil pump 1 operates, wear of the top surface 17e due to friction with the inner rotor 61 and the outer rotor 62 can be more appropriately suppressed. Therefore, the durability of the electric oil pump 1 can be more appropriately improved.

[0120] According to this embodiment, a first through hole 28 is provided in the top wall portion 27, penetrating the top wall portion 27 axially, and a first groove portion 19 is provided on the top surface 17e, recessed on the upward side, i.e., the other side (-Z side) axially, and extending circumferentially. When viewed axially, at least a portion of the first through hole 28 overlaps with the first groove portion 19. Therefore, as described above, the interior of the first groove portion 19 is connected to the interior of the receiving recess 17 via the first through hole 28. Therefore, when the electric oil pump 1 operates, a portion of the oil flowing into the pump section 60 through the suction port 32a flows circumferentially inside the first groove portion 19 and is drawn 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 due to the rotation of the inner rotor 61 and the outer rotor 62 can be increased. Therefore, the flow rate of oil discharged from the pump section 60 can be appropriately increased.

[0121] According to this embodiment, the main body 11 of the outer casing includes: a motor receiving portion 12 for receiving a motor portion 40; and a connecting hole portion 18c connecting the interior of the motor receiving portion 12 to the interior of the receiving recess 17 for the shaft 43 to pass through axially. The top wall portion 27 is a radially extending annular plate shape, and the metal outer casing portion 25 has a cylindrical portion 29 extending upward from the radial inner edge of the top wall portion 27 to the other side (-Z side) axially. Radially, the cylindrical portion 29 is disposed between the shaft 43 and the inner circumferential surface of the connecting hole portion 18c. Therefore, as described above, direct contact between the shaft 43 and the resin-made connecting hole portion 18c can be suppressed. Therefore, when the electric oil pump 1 operates, wear of the connecting hole portion 18c due to friction with the shaft 43 can be suppressed. Therefore, the durability of the electric oil pump 1 can be improved more appropriately.

[0122] According to this embodiment, the housing 10 includes: a resin pump cover 31 that blocks the receiving recess 17 from the lower side, i.e., the axial side (+Z side); and a metal base plate 37 fixed to the upper side, i.e., the other axial side (-Z side) of the pump cover 31, and axially opposite the pump part 60. Therefore, compared to the case where the pump cover 31 is made of metal, the volume of the metal material constituting the housing 10 can be reduced more appropriately. Therefore, the manufacturing cost of the housing 10 can be reduced more appropriately, and the lightweight of the housing 10 can be achieved more appropriately. Therefore, the manufacturing cost of the electric oil pump 1 can be reduced more appropriately, and the lightweight of the electric oil pump 1 can be achieved more appropriately.

[0123] Furthermore, in this embodiment, as described above, the base plate 37 prevents direct contact between the inner rotor 61 and the outer rotor 62 and the resin pump housing 31. Therefore, when the electric oil pump 1 operates, wear of the pump housing 31 due to friction with the inner rotor 61 and the outer rotor 62 can be suppressed. Thus, the electric oil pump 1 can be made lighter, and its durability can be improved more appropriately.

[0124] According to this embodiment, the radially outer end of the base plate portion 37 is located radially outer than the peripheral wall portion 26. Therefore, it is easier to suppress the increase of the gap between the base plate portion 37 and the peripheral wall portion 26, and thus easier to prevent direct contact between the pump portion 60 and the resin pump cover 31 via the gap between the base plate portion 37 and the peripheral wall portion 26. Therefore, when the electric oil pump 1 operates, wear of the pump cover 31 due to friction with the inner rotor 61 and the outer rotor 62 can be more appropriately suppressed. Therefore, the durability of the electric oil pump 1 can be more appropriately improved.

[0125] According to this embodiment, the radially outer end of the base plate portion 37 contacts the downward-facing, axially-facing (+Z-side) surface of the peripheral wall portion 26. Compared to the case where the radially outer end of the base plate portion 37 is located further radially inward than the peripheral wall portion 26, it is easier to make the base plate portion 37 contact the peripheral wall portion 26. In this embodiment, the radially outer end of the base plate portion 37 contacts the downward-facing surface of the peripheral wall portion 26, thus ensuring a firm contact between the base plate portion 37 and the peripheral wall portion 26. Because the base plate portion 37 and the peripheral wall portion 26 are in firm contact, leakage of oil from the interior of the metal casing portion 25 between the base plate portion 37 and the peripheral wall portion 26 can be appropriately suppressed. Therefore, the reduction in the flow rate of oil discharged from the pump portion 60 can be more appropriately suppressed. Therefore, the volumetric efficiency of the pump portion 60 can be improved, and the pump efficiency can be increased.

[0126] According to this embodiment, a second groove 33 is provided on the upward-facing side (the other side of the axial direction, -Z side) of the pump cover 31, which is recessed downward-facing (the other side of the axial direction, +Z side) and extends circumferentially. A second through hole 38 is provided on the bottom plate 37, which extends axially through the bottom plate 37. When viewed axially, at least a portion of the second through hole 38 overlaps with the second groove 33. Therefore, as described above, the interior of the second groove 33 is connected to the interior of the receiving recess 17 via the second through hole 38. Therefore, when the electric oil pump 1 operates, a portion of the oil flowing into the pump section 60 through the suction port 32a flows circumferentially inside the second groove 33 and is drawn into the gap G between the inner rotor 61 and the outer rotor 62 via the second through hole 38. Therefore, the amount of oil moving from the suction chamber A1 to the compression chamber A2 can be increased more appropriately by the rotation of the inner rotor 61 and the outer rotor 62. Therefore, the flow rate of oil discharged from the pump section 60 can be increased more appropriately.

[0127] In this embodiment, as described above, a downward force received from the oil inside the first groove 19 and an upward force received from the oil inside the second groove 33 are applied to the pump section 60. Therefore, when the electric oil pump 1 operates, the vibration of the inner rotor 61 and the outer rotor 62 can be suppressed. As a result, the rotation of the inner rotor 61 and the outer rotor 62 can be stabilized, and thus the decrease in the amount of oil discharged from the pump section 60 and the fluctuation of the oil discharge pressure can be appropriately suppressed.

[0128] <Second Implementation Method>

[0129] Figure 10 This is a perspective view showing the electric oil pump 201 according to this embodiment. In the following description, the same reference numerals are used to denote the constituent elements of the same scheme as in the first embodiment described above, and their descriptions are omitted. Figure 11 As shown, the electric oil pump 201 of this embodiment is used, for example, to supply oil to the mounted body 5. The mounted body 5 may be an automatic transmission, a drive device that drives the axle of a vehicle, or an electric aircraft such as an electric vertical takeoff and landing (EVTOL). The electric oil pump 201 includes a housing 210, a motor 40, a shaft 243, a control device 56, a pump 60, a first sealing member 91, and a second sealing member 92.

[0130] The outer casing 210 is a generally cylindrical shape extending axially. The outer casing 210 houses the motor unit 40, shaft 243, control device 56, and pump unit 60. The outer casing 210 has a main casing portion 211, a cover portion 221, a metal casing portion 225, a pump cover 231, and a base plate portion 237. In this embodiment, the main casing portion 211, cover portion 221, metal casing portion 225, pump cover 231, and base plate portion 237 are independent components.

[0131] The outer casing main body 211 is a cylindrical shape extending axially. More specifically, the outer casing main body 211 is a generally cylindrical shape extending axially about the rotation axis J. The outer casing main body 211 houses the motor part 40, the shaft 243, and the pump part 60 respectively. In this embodiment, the outer casing main body 211 is made of resin. The outer casing main body 211 may also be made of other materials such as metal. Polybutylene terephthalate, polyphenylene sulfide, and polycarbonate can be used as materials constituting the outer casing main body 211. In this embodiment, the outer casing main body 211 is formed by molding the metal outer casing part 225 and the stator 50 of the motor part 40 as inserts. At least a portion of the metal outer casing part 225 is embedded in the outer casing main body 211. Thus, the metal outer casing part 225 is fixed to the outer casing main body 211. The stator 50 is embedded inside the outer casing main body 211. The main body 211 of the housing has a motor housing 212, a pump housing 216 and a plurality of ribs 220.

[0132] The motor housing 212 is the upper part of the main housing 211. The motor housing 212 is positioned above the pump housing 216, on the opposite side (-Z side) axially. The motor housing 212 is a generally cylindrical shape extending axially around the rotation axis J. The motor housing 212 has an opening at its upper side. The motor housing 212 houses the motor portion 40. In this embodiment, the outer diameter (outer shape) of the motor housing 212 is larger than the outer diameter (outer shape) of the pump housing 216. The outer diameter of the motor housing 212 may also be smaller than the outer diameter of the pump housing 216. The motor housing 212 has a first sidewall portion 212a, a third weld portion 212d, a stator holding portion 12g, a stepped portion 212k, and a mounting portion 14. That is, the main housing 211 has a stator holding portion 12g and a third weld portion 212d. The stator 50 is embedded inside the stator holding portion 12g. Thus, the stator holding part 12g holds the stator 50. The configuration of the stator holding part 12g and the mounting part 14 in this embodiment is the same as that in the first embodiment described above.

[0133] The first sidewall portion 212a is a generally cylindrical shape extending axially around the rotation axis J. The first sidewall portion 212a surrounds the upper sides of the motor portion 40 and the shaft 243 from the radially outer side. A first annular groove portion 12c is provided in the first sidewall portion 212a. The configuration of the first annular groove portion 12c in this embodiment is the same as that in the first embodiment described above. A first sealing member 91 is embedded inside the first annular groove portion 12c. In this embodiment, the first sealing member 91 is an O-ring. The first sealing member 91 is annular, surrounding the outer casing body portion 211 from the radially outer side. The first sealing member 91 is mounted on the outer casing body portion 211. Figure 10As shown, the first sealing member 91 is positioned above the plurality of ribs 220, i.e., on the other side of the axial direction (-Z side).

[0134] like Figure 11 As shown, the third weld portion 212d is an annular shape protruding upward from the first sidewall portion 212a. The third weld portion 212d is approximately annular about the rotation axis J. The third weld portion 212d is axially opposed to the cover portion 221. A first protrusion 212e is provided in the third weld portion 212d. The first protrusion 212e is a protrusion protruding upward from the upward-facing surface of the third weld portion 212d. The first protrusion 212e extends circumferentially all around the perimeter.

[0135] The stepped portion 212k protrudes downward from the first sidewall portion 212a and extends circumferentially. The stepped portion 212k is approximately annular about the axis of rotation J. The stepped portion 212k is axially connected to the pump housing portion 216. The outer diameter of the stepped portion 212k is smaller than the outer diameter of the first sidewall portion 212a.

[0136] The pump housing 216 is a generally cylindrical shape extending axially around the rotation axis J. For example... Figure 12 As shown, the downward-facing surface of the pump housing 216 is the lower end of the outer casing main body 211. The pump housing 216 has an opening 217c on the lower side, i.e., on the axial side (+Z side). The pump housing 216 houses the pump part 60 internally. The pump housing 216 surrounds the pump part 60 radially outward. The pump housing 216 has a second sidewall 216a, a first welded portion 216b, and an annular wall 218. That is, the outer casing main body 211 has the first welded portion 216b. A receiving recess 217 is provided in the pump housing 216. That is, the outer casing main body 211 has a receiving recess 217.

[0137] The second sidewall portion 216a is a generally cylindrical shape extending axially around the rotation axis J. The second sidewall portion 216a surrounds the lower sides of both the pump portion 60 and the shaft 243 radially outward. The second sidewall portion 216a is axially connected to the stepped portion 212k. The outer diameter of the stepped portion 212k is larger than the outer diameter of the second sidewall portion 216a.

[0138] The first weld portion 216b is disposed on the lower side of the second sidewall portion 216a. The first weld portion 216b is axially connected to the second sidewall portion 216a. The first weld portion 216b is the lower end of the outer casing main body portion 211. Therefore, the outer casing main body portion 211 has the first weld portion 216b at its axial end. The first weld portion 216b protrudes radially outward from the second sidewall portion 216a. When viewed axially, the first weld portion 216b is annular about the rotation axis J. The first weld portion 216b is axially opposed to the pump cover 231. Figure 15As shown, the first weld portion 216b has a first weld protrusion 216c. The first weld protrusion 216c is a protrusion that protrudes downward from the downward-facing surface of the first weld portion 216b, i.e., to the axial side (+Z side). The first weld protrusion 216c extends circumferentially throughout the entire perimeter. When viewed axially, the first weld protrusion 216c is annular about the rotation axis J. The radial dimension of the first weld protrusion 216c is greater than the axial dimension of the first weld protrusion 216c.

[0139] like Figure 12 As shown, the receiving recess 217 is a hole that is recessed upward from the lower side of the pump receiving portion 216. That is, the receiving recess 217 is a hole that is recessed upward from the lower side of the outer casing body portion 211, i.e., the end on one axial side (+Z side), i.e., the other axial side (-Z side). The pump portion 60 is accommodated inside the receiving recess 217. The receiving recess 217 has an inner peripheral surface 217a and a top surface 217e.

[0140] The inner circumferential surface 217a of the recess is the radially inward-facing surface of the inner surface accommodating the recess 217. When viewed axially, the inner circumferential surface 217a of the recess is approximately circular in shape, surrounding the axis of rotation J. The inner circumferential surface 217a of the recess surrounds the pump portion 60 from the radially outward side. The lower end of the inner circumferential surface 217a is an opening 217c.

[0141] The top surface 217e is the downward-facing surface of the inner surface of the receiving recess 217. The top surface 217e is also the downward-facing surface of the annular wall portion 218. The top surface 217e is axially opposed to the pump portion 60. Other configurations of the receiving recess 217 in this embodiment are the same as those of the receiving recess 17 in the first embodiment described above.

[0142] The annular wall portion 218 is approximately circular about the rotation axis J. The radially outer end of the annular wall portion 218 is circumferentially connected to the radially inward-facing surface of the stepped portion 212k. The annular wall portion 218 is positioned lower than the motor portion 40 and higher than the pump portion 60. The annular wall portion 218 includes an inner cylinder portion 218a, a connecting hole portion 218c, and an outlet hole 218e. That is, the outer casing main body portion 211 has the connecting hole portion 218c.

[0143] The inner cylinder portion 218a protrudes upward from the radial inner edge of the annular wall portion 218. The inner cylinder portion 218a is generally cylindrical about the axis of rotation J. The inner circumferential surface of the inner cylinder portion 218a is axially connected to the inner circumferential surface of the annular wall portion 218.

[0144] The connecting hole 218c is a hole that axially penetrates both the annular wall portion 218 and the inner cylinder portion 218a. The connecting hole 218c is formed by the inner circumferential surface of the annular wall portion 218 and the inner circumferential surface of the inner cylinder portion 218a. When viewed axially, the connecting hole 218c is approximately circular about the rotation axis J. The connecting hole 218c connects the interior of the motor housing portion 212 with the interior of the housing recess 217. The shaft 243 passes axially through the interior of the connecting hole 218c. The outlet hole 218e is a hole that axially penetrates the annular wall portion 218. The outlet hole 218e is located on the radially outer portion of the annular wall portion 218.

[0145] like Figure 10 As shown, each rib 220 is provided on the outer peripheral surface of the second sidewall portion 216a, that is, the radially outward surface of the pump housing portion 216. In other words, each rib 220 is provided on the radially outward surface of the outer casing main body portion 211. Therefore, the strength of the outer casing main body portion 211 can be appropriately increased by each rib 220. Each rib 220 is a plate-shaped part that protrudes radially outward from the pump housing portion 216. Although not shown in the figure, each rib 220 includes a first rib, similar to the first embodiment described above. Although not shown in the figure, similar to the first embodiment described above, the first rib engages with the positioning portion 34a of the pump cover 231. Figure 13 As shown, the ribs 220 are arranged at intervals from each other along the circumferential direction. Figure 10 As shown, each rib 220 extends axially. Figure 12 As shown, the upper end of each rib 220 is connected to the downward-facing surface of the first sidewall portion 212a, and the lower end of each rib 220 is connected to the first welded portion 216b. That is, each rib 220 connects the lower side of the motor housing portion 212 to the first welded portion 216b in the axial direction. Therefore, when the housing body portion 211 is formed, the first welded portion 216b can be prevented from warping upwards as it tends to move radially outwards by means of each rib 220.

[0146] In this embodiment, the lower end of each rib 220 is connected to the radially outward-facing surface of the first weld portion 216b. Therefore, in this embodiment, during the molding of the outer shell body 211, the upward warping of the radially outward-facing end of the first weld portion 216b can be more appropriately suppressed by the ribs 220. It should be noted that the lower end of each rib 220 may not be connected to the radially outward-facing surface of the first weld portion 216b. Furthermore, the upper portion of each rib 220 is connected to the outer surface of the stepped portion 212k. That is, each rib 220 is connected to the stepped portion 212k.

[0147] like Figure 13As shown, the plurality of ribs 220 includes a plurality of first protruding ribs 220e and two second protruding ribs 220g. The number of second protruding ribs 220g included in the plurality of ribs 220 may also be one. When viewed axially, each first protruding rib 220e protrudes from the second sidewall portion 216a in a first direction D1 orthogonal to the axial direction. In this embodiment, the plurality of ribs 220 includes six first protruding ribs 220e. The number of first protruding ribs 220e included in the plurality of ribs 220 is not limited to this embodiment, and may be five or less, or seven or more. Figure 13 The second imaginary line VL2 shown is an imaginary line extending along a second direction D2 that intersects both the axial direction and the first direction D1, and passing through the center of the rotation axis J, i.e., the motor housing 212. In this embodiment, the second direction D2 is orthogonal to both the axial direction and the first direction D1. The second direction D2 may also not be orthogonal to at least one of the axial direction and the first direction D1. When viewed from the axial direction, each of the second protruding ribs 220g protrudes from the second sidewall portion 216a toward the second direction D2. Each of the second protruding ribs 220g is radially opposed across the rotation axis J. When viewed from the axial direction, each of the second protruding ribs 220g overlaps with the second imaginary line VL2. Therefore, according to this embodiment, when the housing body portion 211 is molded by resin molding, when appropriately molding the side surface that intersects the axial direction, the housing body portion 211 having multiple ribs 220 can be molded by using only a pair of molds (sliding molds) that move toward opposite sides of the first direction D1. Therefore, compared to the configuration where each rib 220 protrudes radially outward, the number of molds used in molding the outer shell body 211 can be reduced. Thus, the increase in manufacturing cost and time for the outer shell body 211 can be suppressed. Other configurations of the outer shell body 211 in this embodiment are the same as those of the outer shell body 11 in the first embodiment described above.

[0148] like Figure 11 As shown, the cover portion 221 is a generally cylindrical shape that protrudes axially about the rotation axis J. The cover portion 221 has an opening on its lower side. The cover portion 221 is fixed to the upper end of the outer casing main body portion 211. The cover portion 221 blocks the opening on the upper side of the motor receiving portion 212. A control device 56 is housed inside the cover portion 221. In this embodiment, the cover portion 221 is made of resin. Polybutylene terephthalate, polyphenylene sulfide, and polycarbonate can be used as materials constituting the cover portion 221. The cover portion 221 can also be made of other materials such as metal. The cover portion 221 has a peripheral wall portion 22, a fourth welded portion 222a, and a substrate cover portion 23.

[0149] The fourth weld portion 222a is an annular shape that protrudes radially outward from the lower end of the cover peripheral wall portion 22. When viewed axially, the fourth weld portion 222a is an annular shape centered on the rotation axis J. The fourth weld portion 222a is axially opposed to the third weld portion 212d of the outer casing main body portion 211. A second annular groove portion 22a is provided in the fourth weld portion 222a. The second annular groove portion 22a is a groove that is recessed upward from the lower surface of the fourth weld portion 222a and extends circumferentially. A first protrusion 212e is inserted inside the second annular groove portion 22a. Therefore, the radial position of the cover portion 221 relative to the outer casing main body portion 211 can be determined with high precision. In this embodiment, the lower surface of the second annular groove portion 22a is welded to the first protrusion 212e circumferentially. Thus, the third welded portion 212d and the fourth welded portion 222a are welded together. Therefore, in this embodiment, the outer casing main body 211 and the cover portion 221 can be properly sealed, thereby appropriately improving the airtightness of the electric oil pump 201. Furthermore, since there is no need to provide additional sealing members such as O-rings to seal the outer casing main body 211 and the cover portion 221, the increase in the number of parts in the electric oil pump 201 can be suppressed.

[0150] like Figure 12 As shown, the pump cover 231 is a cylindrical shape extending axially. More specifically, the pump cover 231 is approximately annular about the rotation axis J. The pump cover 231 is positioned below the pump section 60. The pump cover 231 is fixed to the lower end of the pump receiving section 216. The pump cover 231 covers the pump section 60 from below. The pump cover 231 blocks the receiving recess 217 from below, i.e., on the axial side (+Z side). The pump cover 231 blocks the opening 217c from below. In this embodiment, the pump cover 231 is made of resin. Polybutylene terephthalate, polyphenylene sulfide, and polycarbonate can be used as materials constituting the pump cover 231. The pump cover 231 can also be made of other materials such as metal. The pump cover 231 retains the base plate section 237. The pump cover 231 has a cover body section 232, a second welded section 236, and a protruding cylindrical section 35. Figure 14 As shown, the pump cover 231 has cover protrusions 232g, 232h, and 232k.

[0151] like Figure 12 As shown, the main body 232 is the upper part of the pump cover 231. The main body 232 is approximately annular about the axis of rotation J. A suction port 32a and a second groove 33 are provided in the main body 232. Figure 14 As shown, a protrusion 34 is provided in the main body portion 232 of the cover. Although not shown in the figure, as described above, the first rib is fitted into the positioning portion 34a of the protrusion 34. Figure 10As shown, the main body 232 of the pump housing has a discharge port 232c and multiple housing ribs 235. Therefore, the pump housing 231 has a discharge port 232c and multiple housing ribs 235. Figure 15 As shown, the main body portion 232 of the cover has a first plate-shaped portion 236b. That is, the pump cover 231 has a first plate-shaped portion 236b.

[0152] like Figure 10 As shown, the outlet 232c is a hole that penetrates the main body 232 radially. The outlet 232c opens radially. Figure 15 As shown, the outlet 232c is connected to the second discharge side groove 33c. Oil compressed in the pump section 60 is discharged to the outside of the electric oil pump 201 via the outlet 232c. Figure 16 As shown, in this embodiment, the outlet 232c opens towards the second direction D2. The direction of the outlet 232c opening is not particularly limited; it can be the first direction D1, or it can be a direction between the second direction D2 and the first direction D1. Figure 10 As shown, when viewed radially, the outlet 232c is roughly rectangular.

[0153] like Figure 12 As shown, the second weld portion 236 is an annular shape that protrudes radially outward from the upper end of the cover body portion 232. Viewed axially, the second weld portion 236 is an annular shape surrounding the rotation axis J. The second weld portion 236 is the upper end of the pump cover 231. Therefore, the pump cover 231 has a second weld portion 236 at its axial end. The second weld portion 236 is axially opposed to the outer casing body portion 211. More specifically, the second weld portion 236 is axially opposed to the first weld portion 216b. Figure 15 As shown, the second welding portion 236 has a second welding protrusion 236a.

[0154] The second welding protrusion 236a is a protrusion that projects upward from the upward-facing surface of the second welding portion 236, i.e., to the other side (-Z side) axially. The second welding protrusion 236a extends circumferentially. When viewed axially, the second welding protrusion 236a is annular about the axis of rotation J. The radial dimension of the second welding protrusion 236a is greater than its axial dimension. The second welding protrusion 236a is axially opposed to the first welding protrusion 216c of the housing body portion 211. In this embodiment, the first welding protrusion 216c and the second welding protrusion 236a are welded circumferentially. Thus, the first welding portion 216b and the second welding portion 236 are welded together. That is, the pump housing portion 216 and the pump cover 231 are joined together circumferentially by welding. The pump cover 231 is fixed to the downward-facing, i.e., axial side (+Z side) surface of the first weld portion 216b. In this embodiment, the portion of the second weld portion 236 other than the second weld protrusion 236a is axially spaced from the first weld portion 216b.

[0155] like Figure 12 As shown, the cover protrusions 232g, 232h, and 232k are protrusions extending upward from the upward-facing surface of the cover body 232, i.e., the other side (-Z side) axially. The cover protrusions 232g and 232h are axially opposed to the first welded portion 216b with a gap. The cover protrusion 232k is axially opposed to the pump portion 60 with a gap. Figure 14 As shown, when viewed axially, the cover protrusion 232g is provided along the circumferential edges and radially inner edges of the second suction-side groove 33a. When viewed axially, the cover protrusion 232h is provided along the circumferential edges and radially inner edges of the second discharge-side groove 33c. When viewed axially, the cover protrusion 232k is annular, surrounding the base plate 237.

[0156] like Figure 10 As shown, each rib 235 is provided on the outer peripheral surface of the main body 232, i.e., the outer surface of the pump cover 231. Therefore, the strength of the pump cover 231 can be appropriately improved by each rib 235. Each rib 235 is a plate-shaped structure that protrudes radially outward from the main body 232. Figure 16 As shown, the ribs 235 are arranged at intervals along the circumferential direction. Figure 10 As shown, each cover rib 235 extends axially. The upper end of each cover rib 235 is connected to the lower-facing surface of the second weld portion 236. Therefore, during the molding of the pump cover 231, the second weld portion 236 can be prevented from warping downwards as it tends to move radially outwards by means of each cover rib 235.

[0157] like Figure 16As shown, when viewed axially, each rib 235 protrudes from the main body 232 in the second direction D2. As described above, in this embodiment, the outlet 232c opens in the second direction D2. Therefore, each rib 235 protrudes from the outer surface of the pump cover 231 in the direction of opening the outlet 232c. Therefore, according to this embodiment, when the pump cover 231 is formed by injection molding, a pump cover 231 having an outlet 232c and multiple ribs 235 can be formed by using only a pair of molds (sliding molds) that move relative to each other in the direction of opening towards the outlet 232c, i.e., opposite to the second direction D2. Therefore, compared to the case where each rib 235 protrudes radially outward, the number of molds used in forming the pump cover 231 can be reduced. Therefore, the increase in manufacturing cost and manufacturing time of the pump cover 231 can be suppressed.

[0158] The plurality of cover ribs 235 includes a first cover rib 235a and a second cover rib 235c. The first cover rib 235a and the second cover rib 235c are arranged adjacent to each other in the circumferential direction. The first cover rib 235a and the second cover rib 235c are arranged circumferentially separated by a discharge port 232c. The first cover rib 235a is arranged on the circumferential side (+θ side) of the second cover rib 235c. The first cover rib 235a is arranged on the circumferential side of the discharge port 232c. The first cover rib 235a is arranged near the discharge port 232c. The second cover rib 235c is arranged on the other circumferential side (-θ side) of the discharge port 232c. The second cover rib 235c is arranged near the discharge port 232c. Therefore, in this embodiment, cover ribs 235 are respectively arranged on both sides of the discharge port 232c in the circumferential direction.

[0159] like Figure 15 As shown, the first plate-shaped portion 236b is disposed above the outlet 232c, i.e., on the other side of the axial direction (-Z side). The first plate-shaped portion 236b is plate-shaped and extends in a direction orthogonal to the axial direction. The first plate-shaped portion 236b protrudes radially outward from the outlet 232c. Figure 10 and Figure 15 As shown, in this embodiment, the first plate-shaped portion 236b is a circumferential part of the second weld portion 236. The first plate-shaped portion 236b is the portion of the second weld portion 236 that overlaps with the outlet 232c when viewed axially. The first plate-shaped portion 236b may also be a component different from the second weld portion 236. For example... Figure 10 As shown, a recessed portion 236c is provided in the first plate-shaped portion 236b.

[0160] A recess 236c is provided on the downward-facing surface of the first plate-shaped portion 236b, i.e., on the axial side (+Z side). The recess 236c is a recess that extends upwards from the downward-facing surface of the first plate-shaped portion 236b, i.e., on the other axial side (-Z side). Figure 15As shown, the recessed portion 236c is connected to the downward-facing surface of the outlet 232c. That is, the recessed portion 236c is connected to the inner surface of the outlet 232c. Therefore, in this embodiment, the outlet 232c can be located on the upper side, thus making it easier to shorten the distance between the pump portion 60 and the outlet 232c.

[0161] The protruding cylindrical portion 35 has a fourth annular groove portion 35a and a second plate-shaped portion 235f. That is, the pump cover 231 has the second plate-shaped portion 235f. Figure 12 As shown, the fourth annular groove 35a is a groove that is recessed radially inward from the radially outward surface of the protruding cylindrical portion 35 and extends circumferentially. The fourth annular groove 35a extends circumferentially all around. A second sealing member 92 is embedded inside the fourth annular groove 35a. In this embodiment, the second sealing member 92 is an O-ring. The second sealing member 92 is annular, surrounding the pump housing 231 from the radially outward. The second sealing member 92 is mounted on the pump housing 231. Figure 10 As shown, the second sealing member 92 is positioned lower than the outlet 232c, i.e., on the axial side (+Z side). Therefore, in this embodiment, as... Figure 12 As shown, an outlet 232c and multiple ribs 220 can be respectively arranged in the space surrounded by the outer shell body 211, the pump cover 231, the first sealing member 91, the second sealing member 92 and the mounting body 5.

[0162] like Figure 15 As shown, the second plate-shaped portion 235f is disposed on the lower side of the discharge port 232c, i.e., on the axial side (+Z side). The second plate-shaped portion 235f is plate-shaped and extends in a direction orthogonal to the axial direction. The second plate-shaped portion 235f protrudes radially outward from the discharge port 232c. Figure 10 and Figure 15 As shown, in this embodiment, the second plate-shaped portion 235f is a circumferential part of the portion of the protruding cylindrical portion 35 that is higher than the fourth annular groove portion 35a. The second plate-shaped portion 235f is the portion of the portion of the protruding cylindrical portion 35 that is higher than the fourth annular groove portion 35a that overlaps with the discharge port 232c when viewed from the axial direction. Other configurations of the pump cover 231 in this embodiment are the same as those of the pump cover 31 in the first embodiment described above.

[0163] like Figure 12 As shown, the metal outer casing 225 is housed within the outer casing main body 211. As described above, at least a portion of the metal outer casing 225 is embedded in the outer casing main body 211. The metal outer casing 225 is made of metal. In this embodiment, the metal outer casing 225 is made of aluminum. In this embodiment, the metal outer casing 225 is formed by casting. Figure 17 As shown, the metal outer casing 225 has a peripheral wall portion 26, a top wall portion 227, and a cylindrical portion 229. (As shown...) Figure 12 As shown, the metal housing portion 225 has a support surface 225a and a recess 225c.

[0164] The peripheral wall portion 26 is generally cylindrical, surrounding the rotation axis J. The radially outer portion of the peripheral wall portion 26 is embedded inside the second side wall portion 216a. The peripheral wall portion 26 is fixed to the inner peripheral surface 217a of the recess. In the radial direction, the peripheral wall portion 26 is positioned between the pump portion 60 and the inner peripheral surface 217a of the recess.

[0165] like Figure 17 As shown, the top wall portion 227 is a generally annular plate extending radially. The top wall portion 227 is a plate extending radially outward from the lower side of the cylindrical portion 229, i.e., the axial side (+Z side). The top wall portion 227 surrounds the rotation axis J. The upper end of the peripheral wall portion 26 is circumferentially connected to the radially outer end of the top wall portion 227. Figure 12 As shown, in this embodiment, the axial dimension of the top wall portion 227 is larger than the radial dimension of the peripheral wall portion 26. The upper portion of the top wall portion 227 is embedded inside the annular wall portion 218. The top wall portion 227 is fixed to the top surface 217e. Axially, the top wall portion 227 is positioned between the pump portion 60 and the top surface 217e. The shaft 243 passes axially through the interior of the top wall portion 227. The top wall portion 227 supports the shaft 243 so that it can rotate about the rotation axis J. Figure 17 As shown, a top wall through hole 227c and a top wall recess 227e are provided in the top wall portion 227. For example... Figure 12 As shown, a first groove 228 is provided in the top wall portion 227. (As indicated...) Figure 13 As shown, a connecting groove 227h is provided in the top wall portion 227.

[0166] Figure 17 The through hole 227c shown is a hole that penetrates the top wall portion 227 axially. The through hole 227c is located on the radially outer portion of the top wall portion 227. For example... Figure 12 As shown, when viewed from the axial direction, the top wall through hole 227c overlaps with the outflow hole 218e.

[0167] like Figure 17As shown, a top wall recess 227e is provided on the radially outward surface of the top wall portion 227. The top wall recess 227e is a recess that is recessed radially inward from the radially outward surface of the top wall portion 227. The top wall recess 227e opens on the upper side. The top wall recess 227e may also not open on the upper side. A plurality of top wall recesses 227e are provided on the top wall portion 227. In this embodiment, three top wall recesses 227e are provided on the top wall portion 227. The number of top wall recesses 227e provided on the top wall portion 227 may be two or less, or four or more. The top wall recesses 227e are provided at approximately equal intervals along the circumferential direction. Although not shown in the figure, a portion of the outer casing main body portion 211 is located inside each top wall recess 227e. As a result, circumferential rotation of the metal outer casing portion 225 relative to the outer casing main body portion 211 can be suppressed.

[0168] like Figure 12 As shown, the first groove 228 is a groove recessed upward from the downward-facing surface of the top wall 227 towards the other side (-Z side) axially. The first groove 228 has an opening on the lower side. In this embodiment, two first grooves 228 are provided on the top wall 227. The two first grooves 228 include a first suction-side groove 228a and a first discharge-side groove 228c.

[0169] like Figure 13 As shown, when viewed axially, the first intake-side groove 228a and the first discharge-side groove 228c are both approximately arc-shaped grooves extending circumferentially. That is, the first groove 228 is a groove extending circumferentially. The first intake-side groove 228a and the first discharge-side groove 228c are located at different positions circumferentially. The first intake-side groove 228a and the first discharge-side groove 228c are radially opposed. More specifically, the first intake-side groove 228a and the first discharge-side groove 228c are radially opposed across the rotation axis J.

[0170] like Figure 12 As shown, the interior of the second suction-side groove 33a is connected to the suction port 32a. Viewed axially, the second suction-side groove 33a overlaps with the first suction-side groove 228a. Figure 13 and Figure 14 As shown, when viewed axially, the second suction-side groove 33a and the first suction-side groove 228a have approximately the same shape. Figure 13 As shown, when viewed axially, the first suction side groove 228a overlaps with the top wall through hole 227c and the outlet hole 218e. The first suction side groove 228a is connected to the interior of the motor housing 212 via the top wall through hole 227c and the outlet hole 218e.

[0171] like Figure 15 As shown, the second discharge side groove 33c is connected to the discharge outlet 232c. Figure 12As shown, when viewed axially, the second discharge side groove 33c overlaps with the first discharge side groove 228c. Figure 13 and Figure 14 As shown, when viewed from the axial direction, the second discharge side groove 33c and the first discharge side groove 228c have approximately the same shape.

[0172] like Figure 12 As shown, the connecting groove 227h is a groove that is recessed upward from the downward-facing surface of the top wall 227. Figure 13 As shown, the connecting groove 227h is a groove extending linearly in the radial direction. The radially inner end of the connecting groove 227h opens into the inner circumferential surface of the top wall 227. The radially outer end of the connecting groove 227h opens into the first discharge side groove 228c. Thus, the connecting groove 227h connects the interior of the top wall 227 with the first discharge side groove 228c.

[0173] like Figure 17 As shown, the cylindrical portion 229 is a cylindrical shape extending upward from the radial inner edge of the top wall portion 227, i.e., on the other side of the axial direction (-Z side). The cylindrical portion 229 is a generally cylindrical shape extending axially about the rotation axis J. The inner circumferential surface of the cylindrical portion 229 is axially connected to the inner circumferential surface of the top wall portion 227. Figure 12 As shown, the cylindrical portion 229 is disposed inside the communicating hole portion 218c. The shaft 243 passes through the interior of the cylindrical portion 229 in the axial direction. In the radial direction, the cylindrical portion 229 is disposed between the shaft 243 and the inner circumferential surface of the communicating hole portion 218c.

[0174] The support surface 225a is formed by the inner circumferential surface of the top wall portion 227 and the inner circumferential surface of the cylindrical portion 229. Viewed axially, the support surface 225a is circular about the axis of rotation J. The support surface 225a supports the shaft 243 so that it can rotate about the axis of rotation J. As described above, in the radial direction, the cylindrical portion 229 is positioned between the shaft 243 and the inner circumferential surface of the connecting hole portion 218c. Therefore, direct contact between the shaft 243 and the resin-made connecting hole portion 218c can be suppressed, thus suppressing wear of the connecting hole portion 218c when the electric oil pump 201 operates.

[0175] The recess 225c is a recess that is recessed radially outward from the support surface 225a. The recess 225c is provided all around the circumference. In the axial direction, the recess 225c is provided across the top wall portion 227 and the cylindrical portion 229. The top wall portion 227 has a first support portion 227g. The cylindrical portion 229 has a second support portion 229c.

[0176] The first support portion 227g and the second support portion 229c are each part of the support surface 225a. The first support portion 227g is the portion of the inner peripheral surface of the top wall portion 227 located axially between the end of the recess 225c and the lower end of the top wall portion 227. The second support portion 229c is the portion of the inner peripheral surface of the cylindrical portion 229 located axially between the end of the recess 225c and the upper end of the cylindrical portion 229. The first support portion 227g and the second support portion 229c support the shaft 243 respectively. Other configurations of the metal casing portion 225 in this embodiment are the same as those in the first embodiment described above.

[0177] The base plate portion 237 is a generally circular plate that extends radially about the rotation axis J. The base plate portion 237 is fixed to the upward-facing surface of the pump housing 231, i.e., the other side (-Z side) axially. The base plate portion 237 is positioned lower than the pump portion 60. The base plate portion 237 and the pump portion 60 are axially opposed. In this embodiment, the base plate portion 237 contacts the peripheral wall portion 26 of the metal housing portion 225 axially. The base plate portion 237 may also be axially spaced apart from the peripheral wall portion 26. The radially outer end of the base plate portion 237 is located radially outer than the peripheral wall portion 26. The base plate portion 237 is positioned radially inner than the second weld portion 236. That is, the second weld portion 236 is located radially outer of the base plate portion 237. In this embodiment, the base plate portion 237 is made of metal. Aluminum and stainless steel, etc., can be used as the material constituting the base plate portion 237.

[0178] like Figure 12 and Figure 14 As shown, in this embodiment, the base plate portion 237 is fitted with the cover protrusions 232g, 232h, and 232k. Thus, the base plate portion 237 is fixed to the pump cover 231. The base plate portion 237 can be press-fitted into or clearance-fitted with the cover protrusions 232g, 232h, and 232k. The upward-facing surface of the base plate portion 237 is located higher than the cover protrusions 232g, 232h, and 232k. Therefore, direct contact between the pump portion 60 and the resin cover protrusions 232g, 232h, and 232k can be suppressed, thereby reducing wear on the cover protrusions 232g, 232h, and 232k when the electric oil pump 201 is operating. Figure 14 As shown, the base plate portion 237 has a hole portion 237c and a second through hole 38.

[0179] The configuration of the second through hole 38 in this embodiment is the same as that in the first embodiment described above. That is, the second through hole 38 is a hole that penetrates the bottom plate portion 237 axially. In this embodiment, a pair of second through holes 38 are provided in the bottom plate portion 237. The pair of second through holes 38 includes a second suction-side through hole 38a and a second discharge-side through hole 38c. When viewed axially, the pair of second through holes 38 are linearly symmetrical about a third imaginary straight line VL3, which is an imaginary straight line passing through the rotation axis J, i.e., the center of the bottom plate portion 237. When viewed axially, the second suction-side through hole 38a surrounds the second suction-side groove portion 33a. Therefore, as... Figure 12 As shown, the interior of the second suction-side groove 33a is connected to the interior of the receiving recess 217 via the second suction-side through hole 38a. Figure 14 As shown, when viewed axially, the second discharge side through hole 38c surrounds the second discharge side groove 33c. Therefore, as Figure 12 As shown, the interior of the second discharge side groove 33c is connected to the interior of the receiving recess 217 via the second discharge side through hole 38c.

[0180] Figure 14 The hole 237c shown is a hole that penetrates the base plate portion 237 axially. The hole 237c is located on the radially outer side of the base plate portion 237. In this embodiment, the hole 237c opens radially outward. The hole 237c may also not open radially outward. When viewed axially, the hole 237c is located at a position offset from the third imaginary line VL3. Therefore, the shape of the base plate portion 237 viewed axially can be made asymmetrical with respect to the third imaginary line VL3.

[0181] like Figure 11 As shown, the motor section 40 is housed in the motor housing section 212. Axially, the motor section 40 is positioned lower than the control device 56 and higher than the pump section 60. The motor section 40 has a rotor 41 and a stator 50 radially opposed to the rotor 41 with a gap. Figure 12 As shown, in this embodiment, the lower portion of the insulating member 52 is embedded in the stepped portion 212k. This improves the strength of the stepped portion 212k. The configuration of the motor portion 40 in this embodiment is the same as that of the motor portion 40 in the first embodiment described above.

[0182] like Figure 11 As shown, shaft 243 is a roughly cylindrical shape extending axially around the rotation axis J. The upper portion of shaft 243 passes axially through the interior of rotor core 41a. Rotor core 41a is fixed to the outer circumferential surface of shaft 243. That is, rotor 41a is fixed to shaft 243. Figure 12As shown, the axially central portion of shaft 243 passes axially through the interior of cylindrical portion 229 and the interior of top wall portion 227. As described above, shaft 243 is supported by support surface 225a so that it can rotate about rotation axis J. The lower portion of shaft 243 is connected to pump portion 60. Thus, the rotational torque of rotor 41 is transmitted to pump portion 60 via shaft 243.

[0183] like Figure 11 As shown, the control device 56 includes a circuit board 57. The circuit board 57 is disposed above the motor section 40, on the opposite side (-Z side) axially. The circuit board 57 supplies current to the motor section 40. More specifically, the circuit board 57 supplies current to the coil section 53 of the stator 50. The circuit board 57 is housed inside the cover section 221. When current is supplied to the coil section 53, the rotor 41 and the shaft 243 rotate about the rotation axis J, respectively. The configuration of the control device 56 in this embodiment is the same as that of the control device 56 in the first embodiment described above.

[0184] The pump section 60 is housed inside the pump housing 216. Furthermore, the pump section 60 is housed inside the metal casing 225. The pump section 60 is connected to the lower side of the shaft 243, i.e., the axial side (+Z side). The pump section 60 is driven by the power of the motor section 40 to pressurize and pump oil. The pump section 60 of this embodiment is a cycloidal pump. Therefore, the electric oil pump 201 of this embodiment is a positive displacement electric oil pump. The pump section 60 has an inner rotor 61 and an outer rotor 62. The configuration of the pump section 60 in this embodiment is the same as that of the pump section 60 in the first embodiment described above.

[0185] like Figure 12 As shown, the interior of the second suction-side groove 33a is axially connected to the interior of the first suction-side groove 228a via the gap G between the inner rotor 61 and the outer rotor 62 and the second suction-side through hole 38a. In this embodiment, the internal space of the interconnected second suction-side groove 33a, the gap G, and the first suction-side groove 228a are referred to as the suction chamber A1. The suction chamber A1 is connected to the suction port 32a.

[0186] The interior of the second discharge side groove 33c is axially connected to the interior of the first discharge side groove 228c via the gap G between the inner rotor 61 and the outer rotor 62 and the second discharge side through hole 38c. In this embodiment, the internal space of the interconnected second discharge side groove 33c, the gap G, and the internal space of the first discharge side groove 228c are referred to as compression chamber A2. Compression chamber A2 is connected to discharge port 232c.

[0187] When the electric oil pump 201 operates, as the pressure in the suction chamber A1 decreases due to the rotation of the inner rotor 61 and the outer rotor 62, such as Figure 12As indicated by arrow F1, oil flows into the suction chamber A1 through the suction port 32a. More specifically, although not shown in the diagram, the oil flowing into the second suction-side groove 33a flows circumferentially inside the second suction-side groove 33a and is drawn into the gap G through the second suction-side through hole 38a. A portion of the oil drawn into the gap G flows into the first suction-side groove 228a. The oil flowing into the first suction-side groove 228a flows circumferentially inside the first suction-side groove 228a and is again drawn into the gap G.

[0188] When the gap G moves circumferentially due to the rotation of the inner rotor 61 and the outer rotor 62, as... Figure 12 As indicated by arrow F2, oil moves from the suction chamber A1 to the compression chamber A2. Although not shown in the diagram, a portion of the oil drawn into gap G flows into the first discharge side groove 228c. The oil flowing into the first discharge side groove 228c flows circumferentially inside the first discharge side groove 228c and is drawn back into gap G. The oil drawn into gap G flows into the second discharge side groove 33c through the second discharge side through hole 38c. The oil flowing into the second discharge side groove 33c flows circumferentially inside the second discharge side groove 33c. Thus, when the pressure of the oil in the compression chamber A2 increases, as... Figure 12 As indicated by arrow F3, the oil in compression chamber A2 is pumped to the outside of electric oil pump 201 via outlet 232c. Therefore, electric oil pump 201 supplies oil to the installed body 5.

[0189] As described above, the connecting groove 227h connects the interior of the top wall 227 to the first discharge side groove 228c. Therefore, as Figure 12 As indicated by arrow F4, a portion of the oil drawn into gap G and a portion of the oil inside the first discharge side groove 228c flow into the interior of the top wall portion 227, flowing upwards between the shaft 243 and the support surface 225a. Therefore, oil can be supplied between the shaft 243 and the support surface 225a. Thus, the shaft 243 and the support surface 225a can be properly lubricated by the oil, thereby reducing the friction between the shaft 243 and the support surface 225a. Figure 12 As indicated by arrow F4, oil flowing upwards between shaft 243 and support surface 225a flows into motor housing 212. Therefore, oil can be supplied to the interior of motor housing 212. As described above, the oil pressure in compression chamber A2 is high. Therefore, in this embodiment, the flow rate of oil flowing into the interior of top wall portion 227 from the first discharge side groove portion 228c can be increased. Therefore, shaft 243 and support surface 225a can be properly lubricated with oil, and the amount of oil flowing into motor housing 212 can be increased.

[0190] Oil flowing into the motor housing 212 circulates within the motor housing 212 due to the rotation of the rotor 41, cooling the motor unit 40 and the control device 56 respectively. As described above, the first suction side groove 228a is connected to the interior of the motor housing 212 via the top wall through hole 227c and the outlet hole 218e. Therefore, when the electric oil pump 201 operates, when the pressure in the suction chamber A1 decreases, as... Figure 12 As indicated by arrow F5, a portion of the oil circulating inside the motor housing 212 flows into the first suction side groove 228a via the top wall through hole 227c and the outlet hole 218e. The oil flowing into the first suction side groove 228a, together with the oil flowing into the suction chamber A1 from the suction port 32a, is pumped to the outside of the electric oil pump 201 via the outlet port 232c.

[0191] According to this embodiment, the axial dimension of the top wall portion 227 is larger than the radial dimension of the peripheral wall portion 26. Therefore, compared to the case where the axial dimension of the top wall portion 227 is less than or equal to the radial dimension of the peripheral wall portion 26, the axial rigidity of the top wall portion 227 can be improved. As a result, the shaft 243 can be stably supported by the first support portion 227g, thus stabilizing the rotation of the shaft 243 around the rotation axis J. Therefore, the loss of driving force transmitted from the motor portion 40 to the pump portion 60 can be reduced more appropriately. As a result, the reduction in the flow rate of oil discharged from the pump portion 60 can be suppressed. Therefore, the electric oil pump 201 can be made lighter, and the discharge performance of the electric oil pump 201 can be improved more appropriately.

[0192] According to this embodiment, a first groove 228 is provided in the top wall portion 227, which is recessed on the upward side, i.e., the other side of the axial direction (-Z side), and extends circumferentially. Therefore, as described above, when the electric oil pump 201 operates, a portion of the oil flowing into the pump section 60 via the suction port 32a flows circumferentially inside the first groove 228 and is drawn 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 due to the rotation of the inner rotor 61 and the outer rotor 62 can be increased. Therefore, the flow rate of oil discharged from the pump section 60 can be appropriately increased.

[0193] According to this embodiment, a top wall recess 227e is provided on the radially outward surface of the top wall portion 227, which is recessed radially inward, and a portion of the outer casing main body portion 211 is located inside the top wall recess 227e. Therefore, when the metal casing portion 225 is about to rotate around the rotation axis J due to the frictional force between the shaft 243 and the metal casing portion 225 when the electric oil pump 201 is activated, a portion of the outer casing main body portion 211 is engaged with the inner surface of the top wall recess 227e. Therefore, when the electric oil pump 201 is activated, the rotation of the metal casing portion 225 around the rotation axis J can be suppressed.

[0194] According to this embodiment, the top wall portion 227 has a first support portion 227g supporting the shaft 243, and the cylindrical portion 229 has a second support portion 229c supporting the shaft 243. In this embodiment, as described above, the axial dimension of the top wall portion 227 is larger than the radial dimension of the peripheral wall portion 26, thus making it easy to increase the axial dimension of the top wall portion 227. As a result, the axial distance between the first support portion 227g and the second support portion 229c can be made longer relative to the axial distance between the portion of the shaft 243 connected to the inner rotor 61 and the first support portion 227g. Therefore, even when the load applied to the shaft 243 from the pump portion 60 is large, the load applied to the first support portion 227g and the second support portion 229c can be suppressed. Therefore, the increase of friction between the shaft 243 and the first support portion 227g and the second support portion 229c can be suppressed, thus suppressing wear 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.

[0195] According to this embodiment, the pump cover 231 has cover protrusions 232g, 232h, and 232k protruding upwards, i.e., on the other side of the axial direction (-Z side), and the base plate portion 237 is fitted with the cover protrusions 232g, 232h, and 232k. As described above, in this embodiment, the pump cover 231 is made of resin, and the base plate portion 237 is made of metal. Therefore, the difference between the coefficient of linear expansion of the pump cover 231 and the coefficient of linear expansion of the base plate portion 237 is large. Therefore, when the pump cover 231 is formed by molding the base plate portion 237 as an insert for the embedded member, the difference between the amount of thermal shrinkage of the molded pump cover 231 and the amount of thermal shrinkage of the base plate portion 237 is large, and therefore the axial warpage of the second weld portion 236 located on the radially outer side of the base plate portion 237 is prone to increase. In contrast, in this embodiment, after molding the pump cover 231, the base plate portion 237 is fixed to the pump cover 231 by fitting it into the cover protrusions 232g, 232h, and 232k. Therefore, in this embodiment, axial warping of the second weld portion 236 can be suppressed. Therefore, the flatness reduction of the upward-facing surface of the second weld portion 236 can be suppressed. Thus, the second weld portion 236 and the first weld portion 216b can be stably welded around the entire circumference, thereby appropriately suppressing the formation of gaps between the second weld portion 236 and the first weld portion 216b. Therefore, the airtightness between the outer casing body portion 211 and the pump cover 231 can be appropriately improved, thereby appropriately suppressing oil leakage from between the outer casing body portion 211 and the pump cover 231.

[0196] According to this embodiment, a pair of second through holes 38 are provided in the base plate portion 237, which penetrate the base plate portion 237 axially. When viewed axially, the pair of second through holes 38 are respectively linearly symmetrical about a third imaginary straight line VL3, which is an imaginary straight line passing through the center of the base plate portion 237. The base plate portion 237 has a hole portion 237c that penetrates the base plate portion 237 axially at a position offset from the third imaginary straight line VL3. Therefore, as described above, the shape of the base plate portion 237 when viewed axially can be made asymmetrical with respect to the third imaginary straight line VL3. Therefore, in the assembly process of the electric oil pump 201, by confirming the position of the hole portion 237c relative to the pump cover 231 while installing the base plate portion 237 onto the pump cover 231, it is possible to prevent the axially facing surface of the base plate portion 237 from being installed onto the pump cover 231 in a reversed state. Therefore, the base plate 237 can be easily and correctly installed onto the pump cover 231, thus simplifying the installation process. This also helps to reduce the increase in assembly time for the electric oil pump 201.

[0197] It should be noted that, alternatively, in the base plate portion 237, in addition to the hole portion 237c, a circumferentially extending cut may be provided at the circumferential end of one of the pair of second through holes 38. In this case, the shape of the base plate portion 237 as viewed from the axial direction can also be made asymmetrical with respect to the third imaginary line VL3. Therefore, it is possible to prevent the base plate portion 237 from being mounted on the pump cover 231 when the axially facing surface of the base plate portion 237 is reversed.

[0198] According to this embodiment, the electric oil pump 201 is a volumetric electric oil pump. The housing 210 has a resin pump cover 231 that blocks the receiving recess 217 from the lower side, i.e., the axial side (+Z side). The housing body 211 has a first welded portion 216b opposite to the pump cover 231. The first welded portion 216b has a first welded protrusion 216c protruding downward. The pump cover 231 has a second welded portion 236 opposite to the housing body 211. The second welded portion 236 has a second welded protrusion 236a protruding upward, i.e., the other axial side (-Z side). The first welded protrusion 216c and the second welded protrusion 236a are welded together. When the first weld portion 216b and the second weld portion 236 do not have the first weld protrusion 216c and the second weld protrusion 236a respectively, the downward-facing surface of the first weld portion 216b, the upward-facing surface of the second weld portion 236, and the downward-facing surface of the pump portion 60 are all located on the same plane. Therefore, when the pump cover 231 and the pump portion 60 are in axial contact, it is difficult to weld the first weld portion 216b and the second weld portion 236 together. Consequently, it is difficult to improve the bonding strength between the first weld portion 216b and the second weld portion 236. Conventionally, in non-volumetric pumps, a configuration is sometimes used to fix the pump cover 231 to the outer casing body 211 by welding. However, in positive displacement pumps, high-viscosity fluids such as oil are discharged, and therefore the discharge pressure is higher compared to the case of handling low-viscosity fluids such as water, making it difficult to use a configuration to fix the pump cover 231 to the outer casing body 211 by welding. Therefore, in conventional positive displacement pumps, the pump cover 231 is fixed to the outer casing 211 using bolts or other fixing components. That is, while miniaturization, weight reduction, and cost reduction have been desired for positive displacement pumps, the long-standing problem of fixing the pump cover 231 to the outer casing 211 using a welding method without bolts or other fixing components has remained unresolved. In contrast, in this embodiment, the first welding protrusion 216c can be positioned lower than the downward-facing surface of the pump portion 60, and the second welding protrusion 236a can be positioned higher than the upward-facing surface of the pump cover 231. Therefore, the first welding protrusion 216c and the second welding protrusion 236a can be welded together in a state of reliable axial contact. Thus, in this embodiment, the pump cover 231 can be securely fixed to the outer casing 211 by welding. Therefore, compared to fixing the main body 211 of the housing to the pump cover 231 with bolts or the like, the number of parts in the electric oil pump 201 can be reduced. Furthermore, since the number of parts in the electric oil pump 201 can be reduced, the electric oil pump 201 can be made lighter, and manufacturing costs can be lowered.

[0199] According to this embodiment, the radial dimension of the first welding protrusion 216c is greater than the axial dimension of the first welding protrusion 216c, and the radial dimension of the second welding protrusion 236a is greater than the axial dimension of the second welding protrusion 236a. Therefore, when welding the first welding portion 216b and the second welding portion 236a, even if the position of the central axis of the pump cover 231 relative to the central axis of the outer casing 211 is offset radially, it is easy to make the first welding protrusion 216c and the second welding protrusion 236a contact axially. Thus, in this embodiment, the first welding protrusion 216c and the second welding protrusion 236a can be welded easily and reliably, thereby improving the airtightness between the first welding portion 216b and the second welding portion 236a more appropriately. Therefore, oil leakage from between the outer casing 211 and the pump cover 231 can be more appropriately suppressed.

[0200] According to this embodiment, the first welding protrusion 216c can be positioned lower than the downward-facing surface of the pump portion 60, and the second welding protrusion 236a can be positioned higher than the upward-facing surface of the pump cover 231. Therefore, the first welding protrusion 216c and the second welding protrusion 236a can be welded together in a state of reliable axial contact. Thus, in this embodiment, the pump cover 231 can be securely fixed to the outer casing body 211. Furthermore, in this embodiment, as described above, the radial dimension of the first welding protrusion 216c is greater than its axial dimension, and the radial dimension of the second welding protrusion 236a is greater than its axial dimension. Therefore, the welding area between the first welding protrusion 216c and the second welding protrusion 236a can be increased, thereby more appropriately improving the airtightness between the first welding portion 216b and the second welding portion 236a. Therefore, oil leakage between the housing body 211 and the pump cover 231 can be more effectively suppressed. Furthermore, according to this configuration, by welding the first weld portion 216b and the second weld portion 236 without using sealing members such as O-rings, the airtightness between the housing body 211 and the pump cover 231 can be appropriately improved, thus effectively suppressing oil leakage between the housing body 211 and the pump cover 231.

[0201] According to this embodiment, the portion of the second weld portion 236 other than the second weld protrusion 236a is axially opposed to the first weld portion 216b with a gap between them. When the portion of the second weld portion 236 other than the second weld protrusion 236a is in axial contact with the first weld portion 216b, it is difficult for the first weld protrusion 216c and the second weld protrusion 236a to make axial contact, thus making it difficult to reliably weld the first weld protrusion 216c and the second weld protrusion 236a together. In contrast, in this embodiment, the portion of the second weld portion 236 other than the second weld protrusion 236a is axially opposed to the first weld portion 216b with a gap between them, thus enabling the first weld protrusion 216c and the second weld protrusion 236a to make more appropriate axial contact. Therefore, in this embodiment, the first welding protrusion 216c and the second welding protrusion 236a can be welded more reliably, thus improving the airtightness between the first welding portion 216b and the second welding portion 236. Consequently, oil leakage between the housing body 211 and the pump cover 231 can be more effectively suppressed.

[0202] According to this embodiment, the second weld portion 236 is located radially outward of the base plate portion 237. Therefore, compared to a configuration where the second weld portion 236 is located radially inward of the edge of the base plate portion 237, the structures of the second weld portion 236 and the first weld portion 216b in the outer casing body portion 211 can be simplified. Furthermore, since the second weld portion 236 is located radially outward of the base plate portion 237, the workability of welding the first weld portion 216b and the second weld portion 236 can be improved.

[0203] According to this embodiment, such as Figure 15 As shown, the second weld portion 236 (second weld protrusion 236a) overlaps the base plate portion 237 radially. In this embodiment, by positioning the second weld portion 236 (second weld protrusion 236a) to overlap the base plate portion 237 radially, the wall thickness of the portion of the pump cover 231 from the first plate-shaped portion 236b to the second weld portion 236 (second weld protrusion 236a) can be made uniform. Therefore, the formation of shrinkage marks around the first plate-shaped portion 236b and the second weld portion 236 (second weld protrusion 236a) can be suppressed. Therefore, the reduction in flatness of the upward-facing surface of the second weld portion 236 can be more appropriately suppressed. As a result, the second weld portion 236 and the first weld portion 216b can be welded more stably throughout the circumference, thus the generation of gaps between the second weld portion 236 and the first weld portion 216b can be more appropriately suppressed. Therefore, the airtightness between the housing body 211 and the pump cover 231 can be improved more appropriately, and oil leakage between the housing body 211 and the pump cover 231 can be suppressed more appropriately.

[0204] According to this embodiment, the first welding protrusion 216c and the second welding protrusion 236a overlap with the base plate portion 237 in the radial direction. Therefore, in this embodiment, the first welding protrusion 216c and the second welding protrusion 236a are welded together near the position where the base plate portion 237 contacts the peripheral wall portion 26. Thus, oil leakage from the inside of the metal casing portion 25 can be blocked by the first welding protrusion 216c and the second welding protrusion 236a located near the position where the base plate portion 237 contacts the peripheral wall portion 26. Therefore, the amount of oil leaking from the inside of the metal casing portion 25 can be reduced. Therefore, the decrease in the flow rate of oil discharged from the pump portion 60 can be appropriately suppressed. Therefore, the volumetric efficiency of the pump portion 60 can be improved, and the decrease in pump efficiency can be suppressed.

[0205] According to this embodiment, the base plate portion 237 and the peripheral wall portion 26 are in axial contact. Therefore, direct contact between the pump portion 60 and the resin pump cover 231 via the gap between the base plate portion 237 and the peripheral wall portion 26 is easily prevented. Therefore, when the electric oil pump 201 operates, wear of the pump cover 231 due to friction with the inner rotor 61 and the outer rotor 62 can be more appropriately suppressed. Therefore, the durability of the electric oil pump 201 can be more appropriately improved.

[0206] According to this embodiment, the outer casing main body 211 includes: a pump receiving portion 216 that surrounds the pump portion 60 from the radially outer side; and a motor receiving portion 212 that receives the motor portion 40 and is disposed above the pump receiving portion 216, i.e., on the other side of the axial direction (-Z side). A plurality of ribs 220 are provided on the radially outer surface of the pump receiving portion 216, and the plurality of ribs 220 are arranged at intervals along the circumferential direction, connecting the downward-facing, axially-side (+Z side) surface of the motor receiving portion 212 to the first weld portion 216b in the axial direction. Therefore, as described above, in this embodiment, during the molding of the outer casing main body 211, the plurality of ribs 220 can suppress the warping of the first weld portion 216b in a manner that causes it to be located on the upper side as it tends towards the radially outer side. Therefore, the reduction in the flatness of the downward-facing surface of the first weld portion 216b can be suppressed. This allows for a more reliable welding of the first weld portion 216b and the second weld portion 236, thereby improving the airtightness between the housing body 211 and the pump cover 231. Consequently, oil leakage between the housing body 211 and the pump cover 231 can be more effectively suppressed.

[0207] Furthermore, in this embodiment, as described above, the pump cover 231 has a plurality of cover ribs 235 protruding from the outer surface of the pump cover 231, and the upper end of each cover rib 235 is connected to the lower-facing surface of the second weld portion 236. Therefore, as described above, during the molding of the pump cover 231, the warping of the second weld portion 236 in a manner that tends towards the radially outward lower side can be suppressed by each cover rib 235. Therefore, the reduction of the flatness of the upper-facing surface of the second weld portion 236 can be suppressed. As a result, the first weld portion 216b and the second weld portion 236 can be welded more reliably, and thus the airtightness between the outer casing body 211 and the pump cover 231 can be improved more appropriately. Therefore, oil leakage from between the outer casing body 211 and the pump cover 231 can be more appropriately suppressed.

[0208] According to this embodiment, the electric oil pump 201 includes a circuit board 57 disposed above the motor section 40, i.e., on the opposite side (-Z side) of the axial direction, supplying current to the motor section 40. The housing 210 has a resin cover 221 that houses the circuit board 57. The housing body 211 has a third welded portion 212d opposite to the cover 221, and the cover 221 has a fourth welded portion 222a opposite to the third welded portion 212d. The third welded portion 212d and the fourth welded portion 222a are welded together. Therefore, the housing body 211 and the cover 221 can be fixed by welding, thus reducing the number of parts in the electric oil pump 201 compared to fixing the housing body 211 and the cover 221 by bolts or the like.

[0209] The embodiments of the present invention have been described above. However, the various components and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the components can be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0210] The pump housing can also be made of metal. In this case, since the main body of the housing is made of resin, a lightweight design can be achieved. Therefore, a lightweight electric oil pump can be realized. Furthermore, in this case, the housing may not have a base plate.

[0211] The metal housing may also be without a cylindrical portion. In this case, the inner circumferential surfaces of the shaft and the connecting hole can be lubricated with oil, thus suppressing wear on the inner circumferential surfaces of the connecting hole.

[0212] The metal outer casing can also be fixed to the main casing using adhesives or the like. In this case, wear on the main casing can be suppressed by each of the peripheral wall, top wall, and cylindrical portion. Furthermore, the base plate can also be fixed to the pump cover using adhesives or the like. In this case, wear on the pump cover can also be suppressed by the base plate.

[0213] The pump cover may also have a pump housing. In this configuration, the metal outer shell is housed within the pump housing of the pump cover, the base plate is fixed to the outer shell body, and the outer shell body has a first groove. It should be noted that, in this configuration, the base plate may also have a cylindrical portion extending axially to the other side, and ribs may be provided at the corners of the base plate and the cylindrical portion to improve the strength for shaft support.

[0214] The cover may also have a metal plate for preventing the effects of electromagnetic noise. In this case, the cover may also have a protrusion for fitting the metal plate so that the pump cover has a protruding portion that fits into the base plate. That is, the cover may also have a protrusion for fixing the metal plate. In addition, the metal plate may also be fixed to the cover by heat riveting. The protrusion of the cover may be provided on the radially inner side of the cover, or it may be stepped to ensure that the flatness of the fourth welded portion is not reduced.

[0215] In the above embodiment, a configuration is shown where the circuit board is positioned on the opposite side of the motor section along the axial direction, but the circuit board can also be positioned in other locations. The circuit board can also be positioned axially. When the circuit board is positioned axially, the housing body or cover can have a substrate receiving portion that opens radially and accommodates the circuit board. By appropriately configuring a wall portion with radial height in the substrate receiving portion of the housing body or cover, the circuit board, components electrically connecting the stator to the circuit board, etc., can be appropriately accommodated, while maintaining the radial size to the required minimum. Furthermore, since the circuit board is not positioned on the opposite side of the motor section along the axial direction, it can be miniaturized axially. The aforementioned wall portion with radial height can be provided by both the housing body and the cover, or only by one of the housing body or the cover. When the circuit board is positioned axially, the third weld portion of the housing body and the fourth weld portion of the cover can be welded radially by forming a first protrusion and a second annular groove. The first protrusion and the second annular groove are configured as a quadrilateral frame with the long side along the axial direction and the short side along the radial direction. This allows the size of the substrate receiving portion to be reduced to the minimum required size according to the shape of the circuit board, and the housing body and the cover portion can be sealed without the use of sealing members such as O-rings.

[0216] The main body or cover of the outer casing may also have a resin-made columnar boss from the inner side that serves as the substrate receiving portion. Alternatively, the boss of the main body or cover of the outer casing may pass through a hole provided in the circuit board and the circuit board may be fixed by thermal riveting.

[0217] The application of the electric oil pump of the present invention is not particularly limited. The type of fluid transported by the electric oil pump is not particularly limited, and it can be a liquid other than oil, such as water. The electric oil pump can also be mounted on an installation body other than a vehicle. It should be noted that the various components described above in this specification can be appropriately combined without contradiction.

[0218] It should be noted that this technology can be configured as described below.

[0219] (1) An electric oil pump comprising: a motor section having an axially extending shaft, a rotor fixed to the shaft and rotatable, and a stator radially spaced apart from the rotor; a pump section for pumping oil by power from the motor section; and a housing for housing the motor section and the pump section, the pump section having: an inner rotor connected to one axial side of the shaft and having external teeth; and an outer rotor surrounding the inner rotor from the radial outside and having internal teeth that mesh with the external teeth, the housing having a resin housing body and a metal housing body, the housing body having: a receiving recess recessing from one axial side end toward the other axial side and housing the pump section therein; and a stator retaining portion for retaining the stator, the receiving recess having a recessed inner circumferential surface surrounding the pump section from the radial outside, at least a portion of the metal housing body being embedded in the housing body, the metal housing body having a cylindrical peripheral wall portion radially disposed between the pump section and the inner circumferential surface of the recess.

[0220] (2) The electric oil pump according to (1), wherein the receiving recess has a top surface located on the other side of the pump part axially and opposite the pump part in the axial direction, and the metal housing part has a top wall part disposed in the axial direction between the pump part and the top surface.

[0221] (3) The electric oil pump according to (2), wherein the end of the peripheral wall portion on the other side of the axial direction is connected to the end of the top wall portion on the radially outer side of the circumferential direction.

[0222] (4) The electric oil pump according to (2) or (3), wherein a first through hole is provided in the top wall portion to penetrate the top wall portion in the axial direction, and the surface of the top wall portion facing the axial side is located at a position closer to the axial side than the top surface.

[0223] (5) An electric oil pump according to any one of (2) to (4), wherein a first through hole is provided in the top wall portion through the top wall portion in the axial direction, and a first groove portion is provided on the top surface that is recessed to the other side in the axial direction and extends in the circumferential direction, wherein at least a portion of the first through hole overlaps with the first groove portion when viewed from the axial direction.

[0224] (6) The electric oil pump according to (2) or (3), wherein the axial dimension of the top wall portion is greater than the radial dimension of the peripheral wall portion.

[0225] (7) The electric oil pump according to (6) wherein a first groove is provided in the top wall portion, which is recessed to the other side in the axial direction and extends in the circumferential direction.

[0226] (8) The electric oil pump according to (6) or (7), wherein a top wall recess is provided on the radially outward side of the top wall portion, and a portion of the housing body portion is located inside the top wall recess.

[0227] (9) An electric oil pump according to any one of (2) to (8), wherein the housing body has: a motor receiving portion for receiving the motor portion; and a communicating hole portion for connecting the interior of the motor receiving portion to the interior of the receiving recess for the shaft to pass through in the axial direction, the top wall portion being a radially extending annular plate shape, and the metal housing portion having a cylindrical portion extending from the radial inner edge of the top wall portion to the other side in the axial direction, wherein the cylindrical portion is disposed between the shaft and the inner circumferential surface of the communicating hole portion in the radial direction.

[0228] (10) The electric oil pump according to (9), wherein the top wall portion has a first support portion supporting the shaft, and the cylindrical portion has a second support portion supporting the shaft.

[0229] (11) The electric oil pump according to any one of (1) to (10), wherein the housing body is formed by molding the metal housing as an insert of the embedded member.

[0230] (12) The electric oil pump according to any one of (1) to (11), wherein the housing has: a resin pump cover that blocks the receiving recess from one axial side; and a metal base plate that is fixed to the pump cover facing the other axial side and is axially opposite to the pump portion.

[0231] (13) The electric oil pump according to (12), wherein the radially outer end of the base plate portion is located at a position radially outer than the peripheral wall portion.

[0232] (14) The electric oil pump according to (12) or (13), wherein a second groove is provided on the side of the pump cover facing the other side of the axial direction and is recessed to one side of the axial direction and extends circumferentially, and a second through hole is provided on the bottom plate portion that penetrates the bottom plate portion in the axial direction, wherein at least a portion of the second through hole overlaps with the second groove portion when viewed from the axial direction.

[0233] (15) The electric oil pump according to any one of (12) to (14), wherein the pump cover is formed by molding the base plate portion as an insert of the embedded member.

[0234] (16) The pump according to any one of (12) to (14), wherein the pump cover has a cover protrusion projecting axially to the other side, and the base plate portion engages with the cover protrusion.

[0235] (17) The electric oil pump according to (16) wherein a pair of second through holes are provided in the base plate portion through the base plate portion in the axial direction, and when viewed from the axial direction, the pair of second through holes are respectively linearly symmetrical about an imaginary straight line passing through the center of the base plate portion, and the base plate portion has a hole portion through the base plate portion in the axial direction at a position deviating from the imaginary straight line.

[0236] (18) An 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 has a resin pump cover that blocks the receiving recess from one axial side, the main body of the housing has a first welded portion opposite to the pump cover, the first welded portion having a first welded protrusion protruding to one axial side, the pump cover having a second welded portion opposite to the main body of the housing, the second welded portion having a second welded protrusion protruding to the other axial side, the first welded protrusion and the second welded protrusion being welded together.

[0237] (19) The electric oil pump according to (18), wherein the radial dimension of the first welding protrusion is greater than the axial dimension of the first welding protrusion, and the radial dimension of the second welding protrusion is greater than the axial dimension of the second welding protrusion.

[0238] (20) The electric oil pump according to (18) or (19), wherein the portion of the second welded portion other than the second welded protrusion is axially opposed to the first welded portion by a gap.

[0239] (21) The electric oil pump according to any one of (18) to (20), wherein the pump cover has a cover protrusion projecting axially to the other side, and the housing has a metal base plate portion that engages with the cover protrusion.

[0240] (22) The electric oil pump according to (21), wherein the second welded portion is located on the radially outer side of the base plate portion.

[0241] (23) The electric oil pump according to (21) or (22), wherein the base plate portion and the peripheral wall portion are in axial contact.

[0242] (24) An electric oil pump according to any one of (18) to (23), wherein the housing body has: a pump housing portion surrounding the pump portion from the radially outer side; and a motor housing portion housing the motor portion and disposed on the axial side opposite to the pump housing portion, wherein a plurality of ribs are provided on the radially outer side of the pump housing portion, the plurality of ribs being arranged circumferentially spaced apart from each other, and axially connecting one side of the motor housing portion to the first weld portion.

[0243] (25) An electric oil pump according to any one of (18) to (24), wherein the electric oil pump includes a circuit board disposed on the side axially opposite to the motor portion, supplying current to the motor portion, the housing having a resin cover portion that houses the circuit board therein, the housing body portion having a third weld portion opposite to the cover portion, the cover portion having a fourth weld portion opposite to the third weld portion, the third weld portion and the fourth weld portion being welded together.

[0244] (26) A housing body portion, which is a resin housing body portion that accommodates at least a portion of a pump portion and a motor portion in a volumetric electric oil pump and is fused to a resin pump cover, wherein the housing body portion is a cylindrical shape extending axially, the housing body portion having a first fusion portion at an axial end, the first fusion portion having a first fusion protrusion, the first fusion protrusion protruding axially and fused to a second fusion portion of the pump cover.

[0245] (27) A pump cover, which is a resin-made pump cover fused to a resin-made housing body that houses at least a portion of the pump section and the motor section in a positive displacement electric oil pump, wherein the pump cover has a second welded portion at an axial end, the second welded portion having a second welded protrusion that protrudes axially and is fused to a first welded portion of the housing body.

Claims

1. An electric oil pump, comprising: The motor section has an axially extending shaft, a rotor fixed to the shaft and capable of rotation, and a stator that is radially spaced apart from the rotor. The pump unit is driven by the power of the motor unit to pressurize and deliver oil; as well as The housing accommodates the motor and the pump. The pump unit has: An inner rotor, connected to one axial side of the shaft, has external teeth; and An outer rotor, surrounding the inner rotor radially outward, has internal teeth that mesh with the outer teeth. The outer casing has a resin-made outer casing body and a metal-made metal outer casing body. The outer shell body portion has: The receiving recess recesses from one axial side to the other axial side and houses the pump section inside. as well as Stator retaining section, holding the stator. The receiving recess has an inner circumferential surface that surrounds the pump unit from the radially outer side. At least a portion of the metal outer casing is embedded in the outer casing body. The metal housing portion has a cylindrical peripheral wall portion disposed radially between the pump portion and the inner peripheral surface of the recess.

2. The electric oil pump according to claim 1, wherein, The receiving recess has a top surface located on the opposite side of the pump part axially and opposite the pump part axially. The metal housing portion has a top wall portion disposed axially between the pump portion and the top surface.

3. The electric oil pump according to claim 2, wherein, The axial end of the peripheral wall portion is connected to the radially outer end of the top wall portion circumferentially.

4. The electric oil pump according to claim 2, wherein, A first through hole is provided in the top wall portion, extending through the top wall portion in the axial direction. The surface of the top wall facing the axial side is located on the axial side closer than the top surface.

5. The electric oil pump according to claim 2, wherein, A first through hole is provided in the top wall portion, extending through the top wall portion in the axial direction. The top surface is provided with a first groove that is recessed to the other side of the axial direction and extends circumferentially. When viewed from the axial direction, at least a portion of the first through hole overlaps with the first groove.

6. The electric oil pump according to claim 2, wherein, The axial dimension of the top wall is greater than the radial dimension of the peripheral wall.

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

8. The electric oil pump according to claim 6, wherein, The top wall portion has a recessed portion that is radially inward on the radially outward side. A portion of the main body of the outer casing is located inside the recessed portion of the top wall.

9. The electric oil pump according to claim 2, wherein, The outer shell body portion has: Motor housing, housing the motor unit; and The connecting hole connects the interior of the motor housing to the interior of the housing recess, allowing the shaft to pass through axially. The top wall portion is a radially expanding annular plate. The metal outer casing has a cylindrical portion that extends axially from the radial inner edge of the top wall portion to the other side. In the radial direction, the cylindrical portion is disposed between the shaft and the inner circumferential surface of the communicating hole.

10. The electric oil pump according to claim 9, wherein, The top wall portion has a first support portion that supports the shaft. The cylindrical portion has a second support portion that supports the shaft.

11. The electric oil pump according to claim 1, wherein, The outer shell body is formed by molding the metal outer shell body as an insert for an embedded member.

12. The electric oil pump according to any one of claims 1 to 11, wherein, The housing has: a resin pump cover that blocks the receiving recess from one axial side; and a metal base plate that is fixed to the pump cover facing the other axial side and is axially opposite to the pump part.

13. The electric oil pump according to claim 12, wherein, The radially outer end of the base plate is located radially outer than the peripheral wall portion.

14. The electric oil pump according to claim 12, wherein, The pump cover has a second groove on the side facing the opposite axial direction, which is recessed to one side and extends circumferentially. The base plate is provided with a second through hole that extends through the base plate in the axial direction. When viewed from the axial direction, at least a portion of the second through hole overlaps with the second groove.

15. The electric oil pump according to claim 12, wherein, The pump cover is formed by molding the base plate portion as an insert for the embedded component.

16. The electric oil pump according to claim 12, wherein, The pump cover has a cover protrusion that protrudes axially to the other side. The base plate portion fits into the cover protrusion portion.

17. The electric oil pump according to claim 16, wherein, The base plate is provided with a pair of second through holes that extend through the base plate in the axial direction. When viewed from the axial direction, the pair of second through holes are respectively linearly symmetrical about an imaginary straight line passing through the center of the base plate. The base plate portion has a hole that extends axially through the base plate portion at a position deviating from the imaginary straight line.

18. The electric oil pump according to any one of claims 1 to 11, wherein, The electric oil pump is a positive displacement type electric oil pump. The housing has a resin pump cover that blocks the receiving recess from one axial side. The main body of the outer casing has a first welded portion opposite to the pump cover. The first weld portion has a first weld protrusion that protrudes to one axial direction. The pump cover has a second welded portion opposite to the main body of the outer casing. The second weld portion has a second weld protrusion that protrudes axially to the other side. The first welding protrusion and the second welding protrusion are welded together.

19. The electric oil pump according to claim 18, wherein, The radial dimension of the first weld protrusion is greater than the axial dimension of the first weld protrusion. The radial dimension of the second welding protrusion is greater than the axial dimension of the second welding protrusion.

20. The electric oil pump according to claim 18, wherein, The portion of the second welded portion other than the second welded protrusion is axially opposed to the first welded portion by a gap.

21. The electric oil pump according to claim 18, wherein, The pump cover has a cover protrusion that protrudes axially to the other side. The outer casing has a metal base plate portion that fits into the protruding part of the cover.

22. The electric oil pump according to claim 21, wherein, The second welded portion is located radially outward of the base plate portion.

23. The electric oil pump according to claim 21, wherein, The bottom plate portion and the peripheral wall portion are in axial contact.

24. The electric oil pump according to claim 18, wherein, The main body of the housing includes: a pump housing portion that surrounds the pump portion radially outward; and a motor housing portion that houses the motor portion and is disposed on an axially opposite side than the pump housing portion. The pump housing has multiple ribs on its radially outward-facing surface. The plurality of ribs are arranged at intervals along the circumferential direction, and the axial side of the motor housing is axially connected to the first welded portion.

25. The electric oil pump according to claim 18, wherein, The electric oil pump includes a circuit board, which is disposed on the opposite side of the motor unit along the axial direction, and supplies current to the motor unit. The housing has a resin cover that houses the circuit board inside. The outer shell body has a third welded portion opposite to the cover portion. The cover portion has a fourth weld portion opposite to the third weld portion. The third welded portion and the fourth welded portion are welded together.

26. A housing body portion, which is a resin housing body portion in a positive displacement electric oil pump, accommodating at least a portion of a pump section and a motor section, and fused to a resin pump cover, wherein... The main body of the outer shell is a cylindrical shape extending axially. The main body of the outer casing has a first welded portion at its axial end. The first welded portion has a first welded protrusion that protrudes axially and is welded to the second welded portion of the pump cover.

27. A pump cover, which is a resin-made pump cover fused to a resin-made housing body that houses at least a portion of the pump section and the motor section in a positive displacement electric oil pump, wherein, The pump cover has a second welded portion at its axial end. The second welded portion has a second welded protrusion that protrudes axially and is welded to the first welded portion of the outer casing body.

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