Electric pump

Abstract

An electric pump includes a shaft extending in an axial direction, a rotor positioned more toward an outer side in a radial direction than the shaft, a stator surrounding the rotor, a housing covering the stator, and a partition wall portion separating the rotor and the stator. The partition wall portion includes a first partition wall positioned on an upper side of the rotor, and a second partition wall having a tubular shape extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall. The electric pump further includes an auxiliary portion positioned between an upper portion of the housing and the first partition wall. The auxiliary portion is in contact with the first partition wall.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Applications No. 2025-062796, filed on Apr. 4, 2025; No. 2025-136347, filed on Aug. 19, 2025; and No. 2025-062803, filed on Apr. 4, 2025, and U.S. Patent Application Ser. No. 63 / 720,904 filed on Nov. 15, 2024, the entire contents of which are hereby incorporated herein by reference.1. FIELD OF THE INVENTION

[0002] The present disclosure relates to an electric pump.2. BACKGROUND

[0003] An electric pump is known in which a pump assembly is coupled to a motor unit. The motor unit of the electric pump includes, for example, a rotor and a stator surrounding the rotor. A partition wall portion having a tubular shape or a cup shape is provided between the rotor and the stator. The partition wall portion seals the inside of the rotor, and thus a fluid entering the rotor is prevented from leaking to the stator side.

[0004] For reduction in size and weight of the electric pump and improvement in pump efficiency, thinning of the partition wall portion separating the rotor and the stator has been studied. However, thinning the partition wall portion deteriorates rigidity of the partition wall portion, and therefore the thinned partition wall portion easily deforms even with a slight force. When the partition wall portion deforms, the partition wall portion may interfere with the rotor or be broken.SUMMARY

[0005] One aspect of an electric pump according to the present disclosure includes: a shaft extending in an axial direction; a rotatable rotor positioned more toward an outer side in a radial direction than the shaft; a stator surrounding the rotor and positioned more toward the outer side in the radial direction than the rotor; a housing covering the stator and having an upper portion; and a partition wall portion separating the rotor and the stator from each other, in which the partition wall portion includes a first partition wall having a plate shape positioned on an upper side of the rotor and extending in the radial direction, and a second partition wall having a tubular shape extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall, and the electric pump further includes an auxiliary portion positioned between the upper portion and the first partition wall and in contact with the first partition wall.

[0006] The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a perspective view of an electric pump according to one example embodiment as viewed from the other side in an axial direction.

[0008] FIG. 2 is a cross-sectional view of the electric pump of the example embodiment taken along a center axis line.

[0009] FIG. 3 is a perspective view illustrating a state in which a controller is removed from the electric pump of the example embodiment illustrated in FIG. 1.

[0010] FIG. 4 is a perspective view of a first housing of the example embodiment as viewed from one side in an axial direction.

[0011] FIG. 5 is an exploded perspective view of a partition wall portion of the example embodiment as viewed from the other side in the axial direction.

[0012] FIG. 6 is a perspective view of the partition wall portion of the example embodiment as viewed from the one side in the axial direction.

[0013] FIG. 7 is a partially enlarged view illustrating an A portion in FIG. 2.

[0014] FIG. 8 is a partially enlarged view illustrating a B portion in FIG. 2.

[0015] FIG. 9 is a perspective view of the partition wall portion of the example embodiment as viewed from the other side in the axial direction.

[0016] FIG. 10 is a perspective view of a second housing of the example embodiment housing a pump assembly as viewed from the other side in the axial direction.

[0017] FIG. 11 is a perspective view of the second housing of the example embodiment as viewed from the one side in the axial direction.

[0018] FIG. 12 is an exploded perspective view of the pump assembly and the second housing of the example embodiment as viewed from the other side in the axial direction.

[0019] FIG. 13 is a partially enlarged view illustrating a C portion in FIG. 2.

[0020] FIG. 14 is a partially enlarged view illustrating the A portion in FIG. 13.

[0021] FIG. 15 is a partially enlarged view illustrating section A1 of FIG. 7.

[0022] FIG. 16 is a partially enlarged view illustrating section A2 of FIG. 15.DETAILED DESCRIPTION

[0023] Hereinafter, an example embodiment of an electric pump 100 of the present disclosure will be described with reference to the accompanying drawings. Each drawing virtually illustrates a center axis line J of the electric pump 100 of the present example embodiment. In the following description, an axial direction of the center axis line J is simply called “axial direction”, a radial direction about the center axis line J is simply called “radial direction”, and a circumferential direction about the center axis line J is simply called “circumferential direction”. A Z-axis illustrated in each drawing indicates a direction in which the center axis line J extends.

[0024] In the description of the present example embodiment, in order to facilitate understanding of the configuration of each unit and portion, the direction in which the arrow of the Z-axis faces (upper side in the drawing) is called “the other side in the axial direction”. Note that the “the other side in the axial direction” may be simply called “upper side”. In the description of the example embodiment, a direction opposite to the direction in which the arrow of the Z-axis faces is called “one side in the axial direction”. Note that the “one side in the axial direction” may be simply called “lower side”. In the description of the example embodiment, the upper side and the lower side are terms for convenience for describing a relative positional relationship of each unit and portion. The actual arrangement relationship or the like may be an arrangement relationship or the like other than the arrangement relationship or the like indicated by these terms.

[0025] The electric pump 100 of the present example embodiment illustrated in FIGS. 1 and 2 is, for example, a water pump for cooling that sends water as a fluid (refrigerant) or an oil pump for cooling or the like that sends oil as a fluid (refrigerant). FIG. 1 is a perspective view of the electric pump 100 as viewed obliquely from above. FIG. 2 is a cross-sectional view of the electric pump 100 taken along the center axis line J.

[0026] The electric pump 100 of the present example embodiment includes a motor unit 10, a pump assembly 20 positioned on the one side in the axial direction (lower side) of the motor unit 10, a controller 30 positioned on the other side in the axial direction (upper side) of the motor unit 10, and a housing H. The motor unit 10, the pump assembly 20, and the controller 30 are housed in the housing H made of metal. The housing H includes a first housing 11 that houses the motor unit 10, a second housing 21 that houses the pump assembly 20, and a third housing 31 that houses the controller 30. Hereinafter, the configuration of the motor unit 10, the pump assembly 20, and the controller 30 will be described in detail.Motor Unit 10

[0027] As illustrated in FIG. 2, the motor unit 10 includes a shaft 12 positioned on the center axis line J and extending in the direction of the center axis line J (axial direction), a rotor 13 positioned more toward an outside side in the radial direction than the shaft 12, and a stator 15 surrounding the rotor 13. The motor unit 10 is housed in a motor housing portion 11h (FIG. 4) in the first housing 11. FIG. 4 is a perspective view of the first housing 11 as viewed from below.

[0028] As illustrated in FIG. 3, the first housing 11 includes an outer shell 11a having a cylindrical shape and an upper portion 11b provided on the upper side of the outer shell 11a. The upper portion 11b is a disk-shaped member. FIG. 3 is a perspective view illustrating a state in which the controller 30 is removed from the electric pump 100 illustrated in FIG. 1. As illustrated in FIG. 4, the first housing 11 includes a first opening portion 11k that opens toward the pump assembly 20 side. A flange 11m extending toward the outer side in the radial direction is formed at an edge portion of the first opening portion 11k. The flange 11m is formed along the circumferential direction of the edge portion of the first opening portion 11k. A first surface 11n facing the pump assembly 20 is formed at the flange 11m. The first surface 11n is a flat surface without a step except for a groove for housing an O-ring. A plurality of screw holes 11p are formed at the flange 11m. A plurality of screw holes 11p are formed at predetermined intervals along the circumferential direction of the flange 11m.

[0029] As illustrated in FIG. 3, a shaft fixing portion 11c is formed in the upper portion 11b of the first housing 11. An end portion (upper end portion) on the other side in the axial direction of the shaft 12 is fixed to the shaft fixing portion 11c. The shaft fixing portion 11c includes a shaft fixing hole h1 formed at the center of the upper portion 11b. As illustrated in FIG. 7, the upper end portion of the shaft fixing hole h1 is radially enlarged as compared with another portion of the shaft fixing hole h1, and a first step portion s1 having an annular shape is formed by the radially enlarged portion. FIG. 7 is a partially enlarged view illustrating the A portion in FIG. 2.

[0030] As illustrated in FIG. 7, a second step portion 12a expanded in a flange shape is formed at the end portion (upper end portion) on the other side in the axial direction of the shaft 12. The second step portion 12a of the shaft 12 is radially enlarged as compared with another portion of the shaft 12. The shaft 12 is inserted into and fixed to the shaft fixing hole h1. When the shaft 12 is inserted into and fixed to the shaft fixing hole h1, the second step portion 12a of the shaft 12 axially faces the first step portion s1. More specifically, the second step portion 12a comes into axial contact with the first step portion s1. Since the second step portion 12a of the shaft 12 is in axial contact with the first step portion s1, the shaft 12 can be prevented from moving (shifting) to the one side in the axial direction (lower side) even if a pulling force acts on the shaft 12 to the one side in the axial direction (lower side). Fixing of the shaft 12 to the shaft fixing portion 11c is performed by press-fitting.

[0031] As illustrated in FIG. 2, the rotor 13 having a cylindrical shape is arranged more toward the outer side in the radial direction than the shaft 12 so as to surround the shaft 12. The rotor 13 is rotatable about the shaft 12. The rotor 13 includes a rotor core 13a, a magnet 13b, a rotor support plate 13c, a rotor support shaft 13d, and a rotor cover 13f. The rotor core 13a is formed by laminating several tens of laminated steel sheets (electromagnetic steel sheets).

[0032] The rotor support plate 13c is positioned on the upper side and the lower side of the rotor core 13a. The rotor support plate 13c sandwiches the magnet 13b and the rotor core 13a from above and below. The rotor cover 13f covers a side surface of the rotor core 13a. The rotor core 13a is isolated from a fluid (refrigerant) such as water by the rotor cover 13f and the two rotor support plates 13c (waterproof). The rotor support shaft 13d has a tubular shape extending in the axial direction. The rotor support shaft 13d is rotatably attached to the shaft 12 via a bearing 14. In the present example embodiment, the bearing 14 is a sliding bearing. An impeller body 20a of the pump assembly 20 is connected to the lower end of the rotor support shaft 13d. Connection between the rotor support shaft 13d and the impeller body 20a of the pump assembly 20 is performed by press-fitting and welding. Centering is performed by press-fitting, and the connection strength is secured by welding. The configurations of the rotor support shaft 13d and the impeller body 20a of the pump assembly 20 will be described later.

[0033] More specifically, as illustrated in FIG. 2 and FIG. 4, an attachment recess portion 11s for fixing the stator 15 is formed in the inner circumferential surface of the first housing 11. The attachment recess portion 11s has a diameter larger than an inner diameter of the first housing 11 and slightly smaller than an outer diameter of the stator 15. Therefore, in the case of press-fitting, the stator 15 is firmly fixed at a predetermined position in the first housing 11 by being pressed against the attachment recess portion 11s at high pressure in the axial direction from the first opening 11k side by using a press machine or the like as with the shaft 12. On the other hand, in the case of shrink-fitting, the first housing 11 is heated and thermally expanded, and the stator 15 is similarly inserted into the attachment recess portion 11s in the axial direction from the first opening 11k side in a state in which the inner diameter is increased. After insertion, when naturally cooled, the first housing 11 contracts and the attachment recess portion 11s is reduced in diameter and pressed against the stator 15 side, firmly fixing the stator 15 in the first housing 11 as in the case of press-fitting.

[0034] The attachment recess portion 11s and the fixing hole h1 of the upper portion 11b of the first housing 11 can be easily machined by using known lathes or machining centers. For example, after the first housing 11 having a cylindrical shape is formed by casting, the first housing 11 is attached sideways to a chuck side of a lathe. Subsequently, in a state in which the first housing 11 is rotated about the shaft of the first housing 11, a bit part including a cutter bit (cutter tool) for the attachment recess portion 11s and a cutter bit (cutter tool) for the fixing hole h1 is brought close to the first housing 11 side from the first opening 11k side to simultaneously or continuously machine the attachment recess portion 11s and the fixing hole h1. When the attachment recess portion 11s and the fixing hole h1 are machined simultaneously or continuously, a machining accuracy (coaxiality) of the attachment recess portion 11s and the fixing hole h1 is also improved as compared with a case of being separately machined. In the case of machining by using a machining center, the machining accuracy (coaxiality) of the attachment recess portion 11s and the fixing hole h1 can be improved by appropriately fixing the first housing 11 by using a jig.

[0035] The stator 15 is arranged more toward the outer side in the radial direction than the rotor 13 so as to surround the rotor 13. The stator 15 is assembled to an inner circumferential surface of the first housing 11 by shrink fit. The stator 15 includes a stator core 15a, an insulator 15b attached to the stator core 15a, and a plurality of coils 15c attached to the stator core 15a via the insulator 15b. The stator core 15a is formed by laminating several tens of laminated steel sheets (electromagnetic steel sheets) die-cut into a ring shape. A coil winding portion for winding each of the coils 15c is formed inside the stator core 15a. The coil winding portion extends from the stator core 15a toward the center portion.

[0036] The insulator 15b includes a protective material such as resin. The insulator 15b covers the surface of the stator core 15a. That is, the insulator 15b protects the coil 15c by covering the inner circumferential surface of the stator core 15a having a cylindrical shape and the surface of each coil winding portion. The coil 15c includes a winding wire of metal such as copper or aluminum. The coil 15c is wound around each coil winding portion of the stator core 15a.

[0037] A coil lead wire 15d of the coil 15c is connected to a busbar assembly 19 positioned on the upper side of the stator 15. The busbar assembly 19 is connected to the controller 30, and supplies three-phase alternating current power from the controller 30 to each of the coils 15c. Electric conduction from the busbar assembly 19 to each of the coils 15c generates a magnetic flux inside each of the coils 15c. The busbar assembly 19 will be further described later.

[0038] A partition wall portion 16 serving as a seal member is provided between the rotor 13 and the stator 15. FIG. 5 is a perspective view of the partition wall portion 16 as viewed from above. As illustrated, the partition wall portion 16 has a shape of an inverted cup, and an upper portion (first partition wall 16a) of the partition wall portion 16 is supported by the shaft 12. The partition wall portion 16 includes a first partition wall 16a having a disk shape positioned on the upper side, a second partition wall 16b having a cylindrical shape extending downward from an outer circumferential edge portion of the first partition wall 16a, and a third partition wall 16c extending toward the outer side in the radial direction from a circumferential edge portion of the second partition wall 16b. A connection portion 16p between the second partition wall 16b and the third partition wall 16c is machined into a round shape. The partition wall portion 16 is made of metal or resin having sealing performance. FIG. 6 is a perspective view of the partition wall portion 16 as viewed from below. Note that it has been described that the partition wall portion 16 has a shape of an inverted cup, but it may be said that the partition wall portion 16 has a hat (brimmed hat) shape.

[0039] A circumferential edge portion of the third partition wall 16c is provided with a fourth partition wall 16d extending upward. Furthermore, a circumferential edge portion of the fourth partition wall 16d is provided with a fixing portion 16e having a flange shape extending toward the outer side in the radial direction. The first partition wall 16a, the second partition wall 16b, the third partition wall 16c, the fourth partition wall 16d, and the fixing portion 16e form a continuous structure. A plurality of holes 16f through which screws (bolts) pass are formed in the fixing portion 16e. In the present example embodiment, six holes 16f are formed. The holes 16f are provided more toward the outer side in the radial direction than the fixing portion 16e.

[0040] As illustrated in FIG. 5, an outer surface of the second partition wall 16b is provided with a plurality of reinforcing portions 16g continuous to an upper surface of the third partition wall 16c. The reinforcing portions 16g are provided at predetermined intervals in the circumferential direction of the second partition wall 16b. In the present example embodiment, the reinforcing portion 16g is a reinforcing rib. The shape of the reinforcing rib 16g is a right triangle when as viewed from the circumferential direction. A portion corresponding to the opposite side of the reinforcing rib 16g is connected to the outer surface of the second partition wall 16b. A portion corresponding to the adjacent side is connected to the upper surface of the third partition wall 16c. The portion corresponding to the right angle is chamfered in accordance with the round shape of the connection portion 16p between the second partition wall 16b and the third partition wall 16c. The second partition wall 16b and the third partition wall 16c are connected at a right angle at the connection portion 16p.

[0041] The reinforcing rib 16g is arranged between the coils 15c constituting the stator 15. A right angle connection state between the second partition wall 16b and the third partition wall 16c is maintained by the plurality of reinforcing ribs 16g. In a case where the partition wall portion 16 is made of metal, the reinforcing rib 16g is made of metal, and is connected to the partition wall portion 16 by welding, adhesion, or the like. In a case where the partition wall portion 16 is made of resin, the reinforcing rib 16g may be made of metal or may be made of resin. In a case where the partition wall portion 16 is made of resin and the reinforcing rib 16g is made of metal, the reinforcing rib 16g can be integrally molded and assembled when the partition wall portion 16 is molded with a mold. In a case where the partition wall portion 16 is made of resin and the reinforcing rib 16g is also made of resin, the reinforcing rib 16g can be molded at the same time when the partition wall portion 16 is molded with a mold, or the reinforcing rib 16g can be provided as a separate member and joined to the partition wall portion 16 by welding. Since the reinforcing rib 16g made of metal is arranged near the coil 15c, heat of the coil 15c transferred through the space can be dissipated to a fluid positioned inside the partition wall portion 16. The reinforcing rib 16g made of resin can be molded at the same time when the partition wall portion 16 is molded with a mold, and therefore the cost can be reduced.

[0042] As illustrated in FIG. 7, a penetration portion 16h through which the shaft 12 passes is provided in a central portion of the first partition wall 16a. The shaft 12 penetrates through the penetration portion 16h of the partition wall portion 16 and is fixed to the upper portion 11b of the first housing 11. A seal portion 16j is provided between the penetration portion 16h and the shaft 12. As illustrated in FIG. 15, the seal portion 16j includes a first seal recess portion 16m having an annular shape and formed in the circumferential direction of the shaft 12, and a seal member 16k located on the first seal recess portion 16m. FIG. 15 is a partially enlarged view illustrating section A1 of FIG. 7. A slight gap (clearance) is formed between the first seal recess portion 16m and an inner surface of the penetration portion 16h, and the gap is sealed by the seal member 16k. The seal member 16k is composed of an elastic member or an applied member. As the elastic member, an O-ring can be used. On the other hand, a waterproof adhesive can be used as the applied member. The waterproof adhesive is, for example, an adhesive that is semi-liquid at room temperature. The waterproof adhesive is, for example, a silicon-based adhesive or an epoxy-based adhesive. The waterproof adhesive is used by being applied, and the amount of adhesive applied can be adjusted, as appropriate, in accordance with the size of the first sealed recess portion 16m. By adjusting the amount of adhesive applied, it is possible to adjust the shape and size of the seal member 16k. Note that, in FIG. 7 and FIG. 15, the first seal recess portion 16m is provided on an outer surface of the shaft 12, but the first seal recess portion 16m may be provided on the inner surface of the penetration portion 16h, or may be provided on the outer surface of the shaft 12 and on the inner surface of the penetration portion 16h. Further, the first seal recess portion 16m need not be provided, and a configuration may be adopted in which the seal member 16k is filled (interposed) in a gap between a front surface of the shaft 12 in a state of simple penetration and an inner front surface of the penetration portion 16h. If the first seal recess portion 16m is not provided and the seal member 16k is filled, as appropriate, in the gap between the front surface of the shaft 12 and the inner front surface of the penetration portion 16h to seal the gap, the process of machining the first seal recess portion 16m can be omitted. Further, by omitting the first seal recess portion 16m, it is possible to suppress an increase in the arrangement space of the seal member 16k and suppress an increase in the size of the region of the penetration portion 16h penetrated by the shaft 12.

[0043] As illustrated in FIG. 15, the second seal recess portion 16p having an annular shape is provided on an inner edge of an opening of the penetration portion 16h on the one side in the axial direction. A seal member 16q is located on the second seal recess portion 16p. The sealing member 16q is, for example, a member applied in the same manner as the first seal recess portion 16m, that is, a silicone-based adhesive or an epoxy-based adhesive having waterproof properties. A gap between the shaft 12 and an opening on the lower side (one side in the axial direction) of the penetration portion 16h is sealed by the seal member 16q located on the second seal recess portion 16p. Note that, if sufficient sealing performance can be ensured by the first seal recess portion 16m and the seal member 16k, the second seal recess portion 16p may be omitted. In contrast, if sufficient sealing performance can be ensured by the second seal recess portion 16p and the seal member 16q, the first seal recess portion 16m may be omitted.

[0044] Further, as illustrated in FIG. 15, the penetration portion 16h includes an inclined surface 16s extending upward on an inner side of the opening 16n on the upper side (other side in the axial direction). With the inclusion of the inclined surface 16s, the opening 16n on the upper side of the penetration portion 16h widens in a trumpet shape or a funnel shape. As illustrated in FIG. 16, the inclined surface 16s has a length L in the axial direction that is greater than a width W in the radial direction. FIG. 16 is a partially enlarged view illustrating section A2 of FIG. 15. That is, an angle θ between the inclined surface 16s and a front surface 12f of the shaft 12 extending in the axial direction is at least 45°or less, preferably 30°±10°. When the angle θ exceeds 40°, a corner is formed at a portion of the inclined surface 16s that comes into contact with the front surface 12f of the shaft 12, and the corner portion strongly comes into contact with the seal member 16k and causes insertion resistance. Thus, an upper limit of the angle θ being 40°is desirable. Further, when the angle θ is less than 20°, the length L of the inclined surface 16s in the axial direction becomes long, increasing a size of the penetration portion 16h and narrowing the width W of the inclined surface 16s, which makes it difficult to insert the shaft 12. Thus, a lower limit of the angle θ being 20°is desirable.

[0045] A through-hole 16h through which the shaft 12 passes is formed at the center portion of the first partition wall 16a. A circumferential edge portion of the through-hole 16h includes an attachment body 16j having a cylindrical shape so as to extend upward from the through-hole 16h. As illustrated in FIG. 7, the first partition wall 16a is attached to the shaft 12 by passing the shaft 12 through the attachment body 16j and the through-hole 16h. FIG. 7 is a partially enlarged view illustrating the A portion in FIG. 2. By attaching the first partition wall 16a to the shaft 12, the first partition wall 16a having a disk shape is positioned on an upper side of the rotor 13 so as to extend toward the outer side in the radial direction from the shaft 12, and the first partition wall portion 16a covers an upper side of the rotor 13 having a cylindrical shape.

[0046] As illustrated in FIG. 2, the second partition wall 16b extending downward from the outer circumferential edge portion of the first partition wall 16a is positioned between the rotor 13 and the stator 15, and the second partition wall 16b separates the rotor 13 and the stator 15. Furthermore, as illustrated in FIG. 13, a lower side of the stator 15 is covered with the third partition wall 16c extending toward the outer side in the radial direction from a lower circumferential edge portion of the second partition wall 16b and the fourth partition wall 16d. The fourth partition wall 16d is fixed to the first housing 11 by the fixing portion 16e extending in a flange shape toward the outer side in the radial direction from the fourth partition wall 16d. FIG. 13 is a partially enlarged view illustrating the C portion of FIG. 2. That is, the lower side of the partition wall portion 16 is fixed to the first housing 11 by the fixing portion 16e.

[0047] As illustrated in FIG. 7, an O-ring attachment groove 16m is formed on the outer circumferential surface of the shaft 12 at a position where the shaft 12 is fitted to the attachment body 16j. An O-ring 16k is attached to the O-ring attachment groove. The O-ring 16k seals between the shaft 12 and the attachment body 16j. The partition wall portion 16 suitably separates between the rotor 13 and the stator 15, and seals the rotor 13 so that the fluid in the rotor 13 does not leak to the stator 15 side. The second partition wall 16b is not in contact with either the rotor 13 or the stator 15. That is, as illustrated in FIG. 8, a gap c1 is formed between the second partition wall 16b and the rotor 13. A gap c2 is formed between the second partition wall 16b and the stator 15. FIG. 8 is a partially enlarged view illustrating the B portion in FIG. 2.

[0048] As illustrated in FIG. 7, an auxiliary portion 17 is arranged between the first partition wall 16a of the partition wall portion 16 and the upper portion 11b of the first housing 11. Reference sign f2 in FIG. 7 indicates a lower surface (contact surface in contact with the partition wall portion 16) of the auxiliary portion 17. The auxiliary portion 17 has a disk shape as illustrated in FIG. 5. A through-bore 17a is formed at the center of the auxiliary portion 17. The attachment body 16j of the partition wall portion 16 is inserted into the through-bore 17a. Reference sign f1 in FIG. 5 indicates a top surface (surface facing upward) of the first partition wall 16a. By inserting the attachment body 16j into the through-bore 17a, as illustrated in FIG. 7, the top surface f1 of the first partition wall 16a and the contact surface f2 of the auxiliary portion 17 are in entire surface contact with each other. FIG. 9 is a perspective view illustrating a state in which the attachment body 16j of the partition wall portion 16 is inserted into the through-bore 17a of the auxiliary portion 17 (a state in which the auxiliary portion 17 is assembled on the partition wall portion 16).

[0049] Furthermore, as illustrated in FIG. 7, a recess portion 17b having an annular shape is formed on the upper surface of the auxiliary portion 17. The recess portion 17b is formed by a guide wall w1 having an annular shape positioned about the through-bore 17a so as to surround the through-bore 17a. The guide wall w1 is a wall extending in the Z direction. A surface f3 surrounded by the guide wall w1 and facing the other side in the axial direction is a surface receiving a distal end of a screw 18 (a lower end of the screw 18 in FIG. 7). The surface f3, which is a surface receiving the distal end of the screw 18, may be called a receiving surface f3. As illustrated in FIG. 7, an annular space (gap) S is formed around the guide wall w1.

[0050] A surface (lower surface) facing the lower side of the upper portion 11b of the housing 11 is provided with a protrusion portion 11d protruding downward. The protrusion portion 11d is positioned on a lower side of the shaft fixing portion 11c. The protrusion portion 11d has an annular shape. The protrusion portion 11d includes the shaft fixing hole h1 at the center portion. As illustrated in FIG. 7, the protrusion portion 11d having an annular shape is fitted into the recess portion 17b having an annular shape of the auxiliary portion 17. In the fitting, a gap in the radial direction between the protrusion portion 11d and the recess portion 17b is an extremely small gap. The protrusion portion 11d is fitted into the recess portion 17b, whereby the auxiliary portion 17 is in a state of not rattling in the radial direction. The protrusion portion 11d and the recess portion 17b are in what is called a spigot state. Note that as indicated by a white arrow (bidirectional arrow) in FIG. 7, the auxiliary portion 17 is movable in the axial direction (+Z direction and −Z direction) along the protrusion portion 11d.

[0051] As illustrated in FIG. 3, a plurality of screw holes 11f penetrating the upper portion 11b of the housing 11 in the Z direction are formed at the shaft fixing portion 11c of the housing 11. The plurality of screw holes 11f are formed circumferentially about the shaft fixing hole h1. In the present example embodiment, three screw holes 11f are formed at equal intervals circumferentially. The screw 18 serving as a pressing portion is screwed into each of the screw holes 11f. As illustrated in FIG. 5, the screw 18 is a headless fine screw such as a fully threaded bolt or a plunger, and the entire screw 18 can be embedded in the screw hole 11f.

[0052] A lower end portion of the screw 18 is machined into a chamfered shape or a hemispherical shape. As illustrated in FIGS. 7 and 9, the lower end portion of the screw 18 protrudes downward from the screw hole 11f, and a lower end surface of the screw 18 is in contact with the receiving surface f3 of the recess portion 17b of the auxiliary portion 17. A hexagonal hole, a star-shaped hole, or the like is formed at an end portion on the other side in the axial direction (upper end) of the screw 18. The hexagonal hole or the star-shaped hole can be attached with a tool such as a hexagonal wrench or a star-shaped wrench. The screw 18 is screwed into the screw hole 11f from the upper side of the shaft fixing portion 11c using a tool such as a hexagonal wrench. At this time, whether the distal end of the screw 18 is in contact with the receiving surface f3 of the recess portion 17b of the auxiliary portion 17 can be determined, for example, by detecting a change in screw tightening torque of the screw 18. Whether the contact pressure (pressing force) between the distal end (lower end) of the screw 18 and the receiving surface f3 is appropriate can also be determined by detecting a change in screw tightening torque of the screw 18.

[0053] As illustrated in FIG. 2, the gap S is formed around the auxiliary portion 17. The gap S is an annular space about the shaft 12. The gap S is formed by the guide wall w1 of the auxiliary portion 17, the upper portion 11b of the first housing 11, the outer shell 11a of the first housing 11, and n surface on the other side in the axial direction (upper surface) of the stator 15. The busbar assembly 19 is housed at the outer side in the radial direction in the gap S, that is, in the vicinity of an inner surface of the outer shell 11a of the first housing 11.

[0054] The busbar assembly 19 includes an annular assembly body 19a extending along the inner surface of the outer shell 11a of the first housing 11, a coil connection portion 19b, and a substrate side protrusion portion 19c. The coil connection portion 19b and the substrate side protrusion portion 19c are paired. In the present example embodiment, three pairs are provided. The coil connection portion 19b includes a busbar (conductive rod) continuous to the coil lead wire 15d extending from the coil 15c of the stator 15. As illustrated in FIG. 2, the coil connection portion 19b is arranged on an inner side in the radial direction, that is, toward the direction of the guide wall w1 of the auxiliary portion 17.

[0055] The coil connection portion 19b is arranged on the inner side in the radial direction, so that a distal end side of the coil connection portion 19b overlaps the rotor 13 and the auxiliary portion 17 when viewed from the axial direction. The coil connection portion 19b overlaps the rotor 13 and the auxiliary portion 17, whereby it is not necessary to enlarge the gap S housing the coil connection portion 19b in the radial direction. By housing the coil connection portion 19b and the auxiliary portion 17 in the gap S, it is possible to downsize the first housing 11 in the radial direction. The gap S is a space formed in the axial direction. Effective use of the gap S achieves downsizing of the first housing 11 in the radial direction. Since the coil connection portion 19b is arranged at a position lower than the height of the guide wall w1 of the auxiliary portion 17, it is possible to suppress the first housing 11 from upsizing in the axial direction.

[0056] As illustrated in FIGS. 2 and 3, the substrate side protrusion portion 19c is arranged inside a through-bore 11g formed at the upper portion 11b of the first housing 11. In the present example embodiment, three through-bores 11g are formed at the upper portion 11b of the first housing 11. The substrate side protrusion portion 19c is arranged in each of the through-bores 11g. The substrate side protrusion portion 19c is provided with a connection terminal 19d continuous to a busbar of the coil connection portion 19b. As illustrated in FIG. 3, the connection terminal 19d protrudes upward from the substrate side protrusion portion 19c. The connection terminal 19d protrudes upward from the substrate side protrusion portion 19c, whereby the distal end of the connection terminal 19d is electrically connected to the controller 30 when the controller 30 is assembled to the upper portion 11b of the first housing 11.Pump Assembly 20

[0057] As illustrated in FIGS. 2 and 13, the pump assembly 20 is housed in a pump housing portion 20h positioned on the lower side of the motor unit 10. As illustrated in FIG. 10, the pump assembly 20 is arranged at a center portion of the second housing 21 forming the pump housing portion 20h. The second housing 21 includes a support portion 23 supporting an end portion 12b on a lower side of the shaft 12. FIG. 10 is a perspective view of the pump assembly 20 as viewed from above, FIG. 11 is a perspective view of the second housing 21 housing the pump assembly 20 as viewed from below, and FIG. 12 is an exploded perspective view of the second housing 21 and the pump assembly 20 as viewed from the other side in the axial direction (upper side).

[0058] As illustrated in FIG. 10, the second housing 21 includes a second opening portion 21a facing the +Z direction. An edge portion (outer circumferential portion) of the second opening portion 21a is provided with a flange 21m extending toward the outer side in the radial direction. A second surface 21n facing the +Z direction is formed on the flange 21m. The second surface 21n is a flat surface without a step. A plurality of bolt holes 21p are formed in the flange 21m. The bolt holes 21p are formed at predetermined intervals in the circumferential direction of the flange 21m. In the present example embodiment, six bolt holes 21p are formed.

[0059] As illustrated in FIG. 2, the flange 21m of the second housing 21 and the flange 11m of the first housing 11 are fastened by a bolt 24 with the fixing portion 16e of the partition wall portion 16 in between. O-rings 11j and 11j are positioned above and below the fixing portion 16e of the partition wall portion 16, respectively. By the fastening of the flange 21m of the second housing 21 and the flange 11m of the first housing 11, as illustrated in FIG. 13, the second surface 21n of the flange 21m and the first surface 11n of the flange 11m are brought into a state of surface contact with each other with the fixing portion 16e of the partition wall portion 16 in between.

[0060] By sandwiching the fixing portion 16e of the partition wall portion 16 between the flange 11m of the first housing 11 and the flange 21m of the second housing 21 to fix the flange 21m to the flange 11m, it is possible to fix the fixing portion 16e (lower side of the partition wall portion 16) of the partition wall portion 16 to the housing H. That is, an upper side (first partition wall 16a) of the partition wall portion 16 is fixed to the shaft 12 as described above, and a lower side (fixing portion 16e) of the partition wall portion 16 is brought into a state of being fixed to the housing H. The upper side of the partition wall portion 16 is fixed to the shaft 12 and the lower side of the partition wall portion 16 is fixed to the housing H, whereby rigidity and shape stability of the partition wall portion 16 are improved. Improvement in rigidity and shape stability enables thinning of the partition wall portion 16. Since the O-rings 11j and 11j are positioned above and below the fixing portion 16e of the partition wall portion 16, respectively, it is possible to seal the fixing portion 16e of the partition wall portion 16 (the lower side of the partition wall portion 16).

[0061] Furthermore, as illustrated in FIGS. 2 and 11, the second housing 21 includes a suction port 25 continuous to the inside of the pump housing portion 20h and a discharge port 26 positioned at an outer circumferential portion of the pump housing portion 20h. The suction port 25 includes a tube body 25a positioned coaxially with the center axis line J. The suction port 25 is positioned on an end portion on the one side in the axial direction (lower end) of the shaft 12. The suction port 25 is connected to a fluid supply path not illustrated, and sucks the fluid from the fluid supply path to the center portion in the pump housing portion 20h. The suction port 25 has the same diameter as that of the discharge port 26. The suction port 25 is provided with the support portion 23 described later.

[0062] The discharge port 26 includes a tube body 26a positioned in parallel with the center axis line J. The tube body 26a (discharge port 26) is positioned outside relative to the flange 21m of the second housing 21. As illustrated in FIGS. 2 and 11, a lower side of the tube body 26a opens (opens in the-Z direction). An upper side of the tube body 26a is closed. A communication port 26b is formed on a side surface of the tube body 26a. The communication port 26b is connected to an outlet side of a discharge flow path 21j in the pump housing portion 20h. The lower end (discharge port 26) of the tube body 26a is connected to a flow path not illustrated, and discharges the fluid in the pump housing portion 20h to the flow path.

[0063] As illustrated in FIG. 11, the discharge flow path 21j is formed along the circumferential direction of an outer circumferential portion of the second housing 21. The discharge flow path 21j is formed as a part of the second housing 21. The discharge flow path 21j forms an inner surface of the pump housing portion 20h (FIG. 10). As illustrated in FIG. 2, a transverse section (cross section perpendicular to the traveling direction of the fluid) of the discharge flow path 21j is semicircular. The discharge flow path 21j having a semicircular cross section forms a curved portion reaching the outermost diameter of the second housing 21. The discharge flow path 21j collects the fluid sent toward the outer side in the radial direction from the pump assembly 20 and causes the fluid to flow toward the discharge port 26 side.

[0064] As illustrated in FIGS. 12 and 13, a bottom portion 21c of the second housing 21 is planar. An outer circumferential portion of the bottom portion 21c is continuous to an inner circumferential side of the discharge flow path 21j. A center portion of the bottom portion 21c is provided with a projection portion 21d having a tubular shape continuous to the tube body 25a of the suction port 25. The projection portion 21d extends downward from the center portion of the bottom portion 21c. An inner groove 21e is formed along the circumferential direction inside the projection portion 21d. The inner diameter of the inner groove 21e is larger than the inner diameter of the tube body 25a, and therefore the connection portion between the inner groove 21e and the tube body 25a is a step portion. A part of the pump assembly 20 is positioned in the inner groove 21e. The second housing 21 has a curved portion reaching the flange 11m side of the outermost diameter from the suction port 25.

[0065] As illustrated in FIGS. 10 and 13, a step portion 21f is formed along the circumferential direction of the second housing 21 on an inner circumference of an upper portion of the second housing 21. The step portion 21f includes a first wall surface 21g facing toward the inner side in the radial direction and a second wall surface 21h facing the other side in the axial direction. The first wall surface 21g constitutes an inner circumferential surface of the flange 21m of the second housing 21. The first wall surface 21g is continuous with the second surface 21n of the flange 21m. The second wall 21h is positioned on an upper side of the discharge flow path 21j.

[0066] The third partition wall 16c and the fourth partition wall 16d of the partition wall portion 16 are positioned at the step portion 21f. More specifically, as illustrated in FIG. 13, the third partition wall 16c of the partition wall portion 16 is positioned on the second wall surface 21h, and the fourth partition wall 16d of the partition wall portion 16 is positioned on the first wall surface 21g. The lower portions (the third partition wall 16c and the fourth partition wall 16d) of the partition wall portion 16 are positioned at the step portion 21f, whereby shape stability of the lower portion of the partition wall portion 16 is secured.

[0067] As illustrated in FIG. 2, the pump assembly 20 is continuous to a lower side of the rotor 13. In the present example embodiment, the pump assembly 20 is an impeller (vane wheel). In the present example embodiment, the impeller constituting the pump assembly 20 is made of metal. Note that the impeller may be made of resin. As illustrated in FIG. 12, the pump assembly 20 includes the impeller body 20a, a shroud 20b, and a plurality of vanes 20c. The impeller body 20a has a disk shape about the center axis line J. A first through-hole 20d is formed at a center portion of the impeller body 20a. A fitting body 20e having a tubular shape extending upward is formed at an edge portion of the first through-hole 20d.

[0068] As illustrated in FIG. 13, the pump assembly 20 is continuous to the rotor support shaft 13d of the rotor 13, whereby the pump assembly 20 rotates with the rotation of the rotor 13. More specifically, an end portion on the one side in the axial direction (lower end) 13e of the rotor support shaft 13d having a sleeve shape is fitted to the inside of the fitting body 20e of the impeller body 20a by press-fitting. Furthermore, the fitting portion is welded. The impeller body 20a and the rotor support shaft 13d are coupled by press-fitting and welding. The inner diameter of the fitting body 20e is substantially the same as or smaller than the inner diameter of the tube body 25a of the suction port 25.

[0069] As illustrated in FIG. 12, the shroud 20b is a member separate from the impeller body 20a. The shroud 20b is arranged at an interval on the lower side of the impeller body 20a. The shroud 20b has a disk shape that is substantially the same shape as that of the impeller body 20a. A second through-hole 20f is formed at the center of the shroud 20b. An edge portion of the second through-hole 20f is provided with a guide body 20g having a cylindrical shape extending downward. Reference numeral 20j indicates a connection portion between the second through-hole 20f and the guide body 20g. The connection portion 20j has a round shape in order to smooth a fluid flow. As illustrated in FIG. 13, the inner diameter of the guide body 20g is the same as the inner diameter of the tube body 25a of the suction port 25.

[0070] As illustrated in FIG. 13, the guide body 20g is positioned so as to be fitted in the inner groove 21e having an annular shape formed inside the projection portion 21d of the suction port 25. However, since the guide body 20g rotates together with the shroud 20b, it is not in contact with the inner groove 21e. That is, there is a gap in the radial direction between the guide body 20g and the inner groove 21e. A lower surface of the shroud 20b faces the bottom portion 21c of the second housing 21, but is not in contact with the bottom portion 21c. That is, there is a gap in the axial direction (Z direction) between the lower surface of the shroud 20b and the bottom portion 21c.

[0071] As illustrated in FIG. 12, the impeller body 20a is spaced apart from the shroud 20b in the axial direction, and the vane 20c is positioned between the impeller body 20a and the shroud 20b. The vane 20c is a strip-shaped metal piece curved in one direction. In the present example embodiment, seven vanes 20c are arranged at regular intervals in the circumferential direction with the same orientations of curvature of the vanes 20c. Each of the vanes 20c extends from the second through-hole 20f of the shroud 20b to an outer circumferential edge of the shroud 20b. The bottom portion of each of the vanes 20c is fixed to the shroud 20b by welding. An upper portion of each of the vanes 20c is also fixed to the impeller body 20a by welding. The impeller body 20a and the shroud 20b are continuous to each other via the plurality of vanes 20c.

[0072] When the pump assembly (impeller) 20 rotates with the rotation of the rotor 13, the fluid in the pump housing portion 20h is pushed out to the outer circumferential side of the pump assembly 20 by the centrifugal force of the pump assembly 20, and is discharged from the discharge port 26 through the discharge flow path 21j (OUT in FIG. 2). When the fluid is discharged from the discharge port 26, the inside of the pump housing portion 20h has a negative pressure, and therefore the fluid is sucked into the pump housing portion 20h from the suction port 25 (IN in FIG. 2). The fluid is continuously sent from the pump assembly 20 by a similar action. The inside of the pump housing portion 20h communicates with a space in which the rotor 13 is housed. Therefore, with the rotation of the pump assembly 20, the fluid in the pump housing portion 20h partially flows into the rotor 13 side. However, since the rotor 13 and the stator 15 are isolated and sealed by the partition wall portion 16, the fluid in the rotor 13 does not flow (does not leak) to the stator 15 side. In the pump housing portion 20h, pressure fluctuation constantly occurs due to a fluid flow (discharge and suction). The pressure fluctuation also acts on the partition wall portion 16 facing the inside of the pump housing portion 20h.

[0073] As illustrated in FIGS. 2 and 13, the support portion 23 is arranged at an axial center portion of the pump assembly 20. The support portion 23 supports the end portion 12b of the lower side (one side in the axial direction) of the shaft 12. The support portion 23 includes a shaft fitting portion 23a and a plurality of support legs 23b. As illustrated in FIGS. 13 and 14, the shaft fitting portion 23a is positioned inside the fitting body 20e of the impeller body 20a. A first recess portion 23c recessed on the one side in the axial direction (lower side) is formed on an end surface on the other side in the axial direction (upper side) of the shaft fitting portion 23a. The end portion 12b of the shaft 12 is fitted into the first recess portion 23c. FIG. 14 is a partially enlarged view illustrating the A portion in FIG. 13.

[0074] The first recess portion 23c has a shape matching the outer shape of the end portion 12b of the shaft 12. As seen from FIG. 12, the outer shape of the end portion 12b of the shaft 12 includes a portion having a circular cross section and a cutout (plane portion) 12d. Therefore, the shape of the first recess portion 23c is a shape matching the circular cross section and the cutout 12d. If the end portion 12b of the shaft 12 has a polygonal shape, the first recess portion 23c also has a shape matching the polygonal shape. If the end portion 12b of the shaft 12 has a projection, a key groove, or the like, the first recess portion 23c also has a shape matching the projection or the like. The end portion 12b of the shaft 12 may be machined so as to be snap-fitted to the first recess portion 23c. In this case, both are joined only by fitting the end portion 12b of the shaft 12 into the first recess portion 23c. Furthermore, the first recess portion 23c may have a step portion by cutting, for example, not only a hole but also a wide groove.

[0075] As illustrated in FIGS. 12 and 14, a washer 14a is provided between the shaft fitting portion 23a and the bearing 14. The washer 14a prevents wear due to direct contact between the bearing 14 rotating together with the rotor 13 and the fitting portion 23a that is fixed. Furthermore, as illustrated, a projection 14b having a linear shape is formed at a part of an inner circumference of the washer 14. The projection 14b is positioned so as to be fitted into the cutout 12d of the end portion 12b of the shaft 12 when the end portion 12b of the shaft 12 passes through the washer 14. The projection 14b of the washer 14a is positioned in the cutout 12d, whereby the cutout 12d also functions as a rotation stopper of the washer 14a (prevention of co-rotation of the washer 14a).

[0076] As illustrated in FIG. 14, a second recess portion 12c extending in the axial direction is formed at the end portion 12b of the shaft 12. In the present example embodiment, the second recess portion 12c is a screw hole. A fixing member 22 for fixing the shaft fitting portion 23a to the end portion 12b of the shaft 12 is screwed into a screw hole 12c. In the present example embodiment, the fixing member 22 is a screw or a bolt. A through-bore 23e continuous to the first recess portion 23c is formed at the center portion of the shaft fitting portion 23a. The through-bore 23e is positioned below the first recess portion 23c. The fixing member (screw) 22 is screwed into the through-bore 23e from the one side in the axial direction (lower side) toward the other side in the axial direction (upper side). A screw 22 includes a screw head portion 22b at the end portion (lower end) on the one side in the axial direction. The screw head portion 22b includes a screw end surface 22a facing the other side in the axial direction (upper side).

[0077] As illustrated in FIG. 14, when the screw 22 is screwed into the screw hole 12c of the end portion 12b of the shaft 12 from the lower side of the through-bore 23e, the screw head portion 22b comes into contact with a first end surface 23g of the shaft fitting portion 23a. The first end surface 23g faces the one side in the axial direction (lower side) so as to face the screw end surface 22a of the screw head portion 22b. A gap s3 is formed in the axial direction between a second end surface 23h of the first recess portion 23c of the shaft fitting portion 23a and the end surface 12e of the end portion 12b of the shaft 12. The second end surface 23h faces the other side in the axial direction (upper side) so as to face the end surface 12e of the end portion 12b of the shaft 12.

[0078] A hole 22e (a hexagonal hole, a star-shaped hole, or the like) into which a tool for turning (screwing) the screw 22 is fitted is formed at the screw head portion 22b of the screw 22. A tool such as a hexagonal wrench or a star-shaped wrench can be fitted in the hole 22e. When the support portion 23 is fixed to the end portion 12b of the shaft 12 by screwing the screw 22 into the screw hole 12c of the end portion 12b of the shaft 12 using a tool such as a hexagonal wrench, the end portion 12b of the shaft 12 is pulled on the support portion 23 side (tension in the −Z direction acts on the end portion 12b of the shaft 12). That is, when the screw 22 is tightened, a force bringing the end portion 12b of the shaft 12 and the support portion 23 close to each other is generated in the axial direction. As illustrated in FIG. 13, since the suction port 25 is positioned on an extension line on the one side in the axial direction of the screw 22, the screw 22 can be screwed to the end portion 12b of the shaft 12 using the suction port 25.

[0079] As illustrated in FIG. 13, the shaft fitting portion 23a is supported by the plurality of support legs 23b present on the lower side of the shaft fitting portion 23a. In the present example embodiment, three support legs 23b support the shaft fitting portion 23a. As illustrated in FIG. 13, the support leg 23b extends from an inner wall surface of the tube body 25a of the suction port 25 to the other side in the axial direction. More specifically, the support leg 23b extends obliquely upward from the inner wall surface of the tube body 25a of the suction port 25 by a predetermined length, and then extends in parallel with the center axis line J. An upper end of the support leg 23b passes through the first through-hole 20d and the second through-hole 20f of the pump assembly 20, and is continuous to the first end surface 23g of the shaft fitting portion 23a. In the present example embodiment, the three support legs 23b are arranged at equal intervals (120°) in the circumferential direction of the tube body 25a about the center axis line J.

[0080] As illustrated in FIG. 13, the end portion 12b of the shaft 12 is positioned above (on the other side in the axial direction) the third partition wall 16c of the partition wall portion 16. That is, the end portion 12b of the shaft 12 does not reach the pump assembly 20 side. Therefore, the shaft fitting portion 23a supporting the end portion 12b of the shaft 12 is present at a position protruding above (on the other side in the axial direction) the third partition wall 16c of the partition wall portion 16, that is, on the motor housing portion 11h side of the first housing 11.

[0081] In the present example embodiment, as illustrated in FIG. 7, the second step portion 12a of the shaft 12 is placed on the shaft fixing portion 11c of the upper portion 11b of the first housing 11. Therefore, as illustrated in FIG. 13, a structure in which the end portion 12b of the shaft 12 is fixed to the support portion 23 by a fixing member such as the screw 22 is provided, but in a case of a structure in which the shaft 12 rotates together with the rotor 13, a bearing member may be newly attached to the support portion 23 in place of the screw 22. The impeller constituting the pump assembly 20 may be a trochoid pump assembly, a gear pump assembly, or a vane pump assembly. In the present example embodiment, the shaft fitting portion 23a of the support portion 23 is positioned on the other side in the axial direction (upper side) relative to the pump assembly 20, but the shaft 12 may be extended to be positioned on the one side in the axial direction (lower side) of the pump assembly 20.Controller 30

[0082] The controller 30 supplies a drive current to the motor unit 10. As illustrated in FIG. 2, the controller 30 includes a third housing 31 having a substrate housing chamber 30a, a substrate 32 housed in the substrate housing chamber 30a, and an electronic component 33. The third housing 31 is made of metal such as aluminum or steel material excellent in thermal conductivity. An upper surface of the third housing 31 is provided with a cooling fin 31a, a cable connection portion 31b, and the like. A sleeve 31c extending toward the one side in the axial direction is formed on a lower side of the third housing 31. The sleeve 31c is fitted so as to cover the upper portion 11b of the first housing 11 from the outside.

[0083] The substrate 32 is mounted with an electronic component 33. The electronic component 33 includes, for example, an IC, a transistor, and a capacitor. The electronic component 33 constitutes a control circuit for controlling the electric pump 100. The substrate 32 is attached to the upper side of the upper portion 11b of the first housing 11. Power supply is performed from the substrate 32 to the coil 15c of the stator 15 via the connection terminal 19d of the busbar assembly 19, and the stator 15 operates.Actions and Effects

[0084] Since the electric pump 100 of the present example embodiment includes the auxiliary portion 17 between the upper portion 11b of the first housing 11 and the first partition wall 16a of the partition wall portion 16, the auxiliary portion 17 presses the first partition wall 16a. Since the auxiliary portion 17 can press the first partition wall 16a, the shape of the partition wall portion 16 can be stabilized, and deterioration in rigidity of the partition wall portion 16 can be compensated even if the partition wall portion 16 is thinned. Since deformation of the partition wall portion 16 can be prevented by compensating for the deterioration in rigidity of the partition wall portion 16, it is possible to avoid breakage of the partition wall portion 16 itself and to avoid interference between the partition wall portion 16 and the rotor 13 or the stator 15. The auxiliary portion 17 is a member that assists the partition wall portion 16.

[0085] In other words, since the rigidity of the partition wall portion 16 can be secured by the auxiliary portion 17 assisting the partition wall portion 16, the partition wall portion 16 can be thinned. Furthermore, thinning the partition wall portion 16 eliminates the necessity of widening the interval (air gap) between an outer diameter surface of the rotor 13 and an inner diameter surface of the stator 15. Since it is possible to maintain a state of narrowing the gap between the outer diameter surface of the rotor 13 and the inner diameter surface of the stator 15, it is possible to suppress deterioration in the magnetic flux density in the air gap, and to suppress deterioration in motor performance.

[0086] In the present example embodiment, as illustrated in FIG. 8, the gap c1 is formed between the second partition wall 16b of the partition wall portion 16 and the outer diameter surface of the rotor 13, and the gap c2 is formed between the second partition wall 16b and the inner diameter surface of the stator 15. That is, the second partition wall 16b is not in contact with the inner diameter surface of the stator 15. Even in a state in which the second partition wall 16b is not in contact with the inner diameter surface of the stator 15, the first partition wall 16a is assisted so as to be pressed from the upper side of the first partition wall 16a by the auxiliary portion 17, and therefore the rigidity of the first partition wall 16a can be secured. A configuration in which the second partition wall 16b is fixed to the inner diameter surface of the stator 15 by press-fitting or the like in order to secure rigidity of the partition wall portion 16 is conceivable, but in the electric pump 100 of the present example embodiment, the second partition wall 16b is not fixed to the stator 15 by press-fitting or the like, and therefore workability when assembling the electric pump 100 is excellent.

[0087] In the present example embodiment, as illustrated in FIG. 7, the first partition wall 16a includes the top surface f1 facing upward, and the auxiliary portion 17 includes the contact surface f2 in contact with the top surface f1. The top surface f1 and the contact surface f2 are brought into surface contact with each other, thereby enabling the auxiliary portion 17 to press the first partition wall 16a with the surface. By pressing the first partition wall 16a with the surface of the auxiliary portion 17, it is possible to suitably improve the rigidity of the first partition wall 16a as compared with a case of pressing with a point or a line.

[0088] In the present example embodiment, as illustrated in FIG. 7 and FIG. 15, the seal portion 16j is provided between the penetration portion 16h of the partition wall portion 16 and the shaft 12, making it possible to prevent leakage of fluid such as refrigerant on the rotor side from a gap between the shaft 12 and the penetration portion 16h even when the shaft 12 is passed therethrough. Further, the seal portion 16j is formed by the first seal recess portion 16m formed on the inner side of the penetration portion 16h or the front surface of the shaft 12 and the seal member 16k located on the first seal recess portion 16m, making it possible to more suitably prevent leakage of the fluid from the gap between the shaft 12 and the penetration portion 16h. Further, an elastic member such as an O-ring or an applied member such as a silicon-based adhesive or an epoxy-based adhesive is used as the seal member 16k, making it possible to more suitably prevent leakage of the fluid from the gap (clearance) between the shaft 12 and the penetration portion 16h.

[0089] Furthermore, in the present example embodiment, as illustrated in FIG. 15, the seal portion 16j includes the second seal recess portion 16p having an annular shape and formed on the inner side of the opening of the penetration portion 16h on the one side in the axial direction and the seal member 16q located on the second seal recess portion 16p, making it possible to suitably prevent leakage of the fluid from the gap (clearance) between the shaft 12 and the penetration portion 16h. Further, the first seal recess portion 16m can be omitted by providing the second seal recess portion 16p and the seal member 16q on the inner side of the opening on the one side of the penetration portion 16h in the axial direction. With the first recess portion 16m being omitted, the height (length) of the penetration portion 16h in the axial direction can be reduced (shortened), making it possible to reduce the size of the seal portion 16j in the axial direction.

[0090] In the present example embodiment, as illustrated in FIG. 15, the inclined surface 16s widening to the other side in the axial direction is further provided on the inner side of the opening 16n of the end portion of the penetration portion 16h on the other side in the axial direction, widening the opening 16n of the end portion of the penetration portion 16h on the other side in the axial direction in a trumpet shape or a funnel shape. With the opening 16n at the end portion on the other side in the axial direction being widened in a trumpet shape or a funnel shape, it is possible to smoothly insert the penetration portion 16h onto the shaft 12 from the other side in the axial direction. Further, in a case in which the seal member 16k of the first seal recess portion 16m is an elastic member such as an O-ring, when the penetration portion 16h is inserted onto the shaft 12 from the other side in the axial direction, it is possible to avoid direct contact of the edge of the opening of the penetration portion 16h with the O-ring. With the edge of the opening 16n of the penetration portion 16h not coming into contact with the O-ring, the O-ring is not damaged by the edge of the penetration portion 16h during insertion, making it possible to ensure the original sealing performance of the O-ring.

[0091] On the other hand, in a case in which the seal member 16k of the first seal recess portion 16m is an applied member (adhesive), the adhesive applied and filled in the first seal recess portion 16m in advance is not scraped out by the edge of the opening 16n of the penetration portion 16h when the penetration portion 16h is inserted onto the shaft 12, and firmly stays in the first seal recess portion 16m. Further, when excessive adhesive that cannot be applied and filled in the first seal recess portion 16m exists, the adhesive is guided to the inclined surface 16s as is and filled in the gap between the inclined surface 16s and the shaft 12, making it possible to exhibit sealing performance in that area. Further, with the inclined surface 16s being formed at the opening 16n of the penetration portion 16h, when the penetration portion 16h is inserted from the one side of the shaft 12 in the axial direction and moved to the other side in the axial direction, the edge of the opening 16n of the penetration portion 16h does not catch on the front surface of the shaft 12. By preventing the opening 16n of the penetration portion 16h from being caught on the shaft 12, it is possible to suppress a bias of the penetration portion 16h and thus suppress deterioration of the coaxiality of the partition wall portion 16 relative to the shaft 12 and the stator 15.

[0092] In the present example embodiment, as illustrated in FIG. 7, the shaft 12 is fixed to the shaft fixing portion 11c formed at the upper portion 11b of the first housing 11, and the partition wall portion 16 is supported by the shaft 12. The shaft fixing hole h1 through which the shaft 12 passes is formed at the shaft fixing portion 11c, and the shaft 12 is fixed through the shaft fixing hole h1. Therefore, it is not necessary to support the shaft 12 by the partition wall portion 16 itself. Therefore, it is not necessary to increase the rigidity of the partition wall portion 16 in order to support the shaft 12. The shaft 12 is fixed to the first housing 11, and the partition wall portion 16 does not need to have rigidity high enough to support the shaft 12, and therefore the partition wall portion 16 can be made small or thin. The upper side of the partition wall portion 16 is fixed by fixing the shaft 12 to the shaft fixing portion 11c. This eliminates the need for a structure for fixing the partition wall portion 16, and therefore the first housing 11 can be downsized in the axial direction and the radial direction.

[0093] In the present example embodiment, the auxiliary portion 17 is pressed on the first partition wall 16a side by the screw 18 via the receiving surface f3. Therefore, the auxiliary portion 17 can constantly firmly press and assist the partition wall portion 16 without being affected by gravity or the like. In the present example embodiment, the screw 18 is used as a pressing portion for pressing the auxiliary portion 17, but the pressing portion is not limited to the screw. Since the pressing portion presses the auxiliary portion 17 on the first partition wall 16a side, another mechanical element having a function of pressing the auxiliary portion 17 on the first partition wall 16a side may be used as a pressing portion similarly to the screw 18. For example, in place of the screw 18 or together with the screw 18, an elastic body such as a spring (leaf spring or coil spring) or rubber may be used.

[0094] In the present example embodiment, a plurality (three) of the screws 18, which are pressing portions, are included at equal intervals in the circumferential direction of the center axis line J. By including the plurality (three) of screws 18, which are the pressing portions 18, it is possible to uniformly press the auxiliary portion 17 from the upper portion 11b of the first housing 11. However, the number, installation intervals, and the like of the screws 18 are not limited to those of the present example embodiment.

[0095] In the present example embodiment, the protrusion portion 11d of the upper portion 11b of the first housing 11 is fitted into the recess portion 17b of the auxiliary portion 17 to be brought into a fitting (spigot) state. Therefore, even if the pressing portion 18 such as the screw 18 locally or nonuniformly presses the auxiliary portion 17, the fitting place serves as a guide, and the auxiliary portion 17 can stably move straight downward to uniformly press the first partition wall 16a without tilting the auxiliary portion 17.

[0096] Furthermore, in the present example embodiment, as illustrated in FIG. 7, the screw 18, which is a pressing portion, is positioned on the center axis line J side relative to a fitting surface f4 between the protrusion portion 11d and the recess portion 17b. Therefore, even if the auxiliary portion 17 is pressed by the screw 18, the auxiliary portion 17 can be suppressed from tilting with respect to the center axis line J. That is, since the screw 18 presses a center side of the auxiliary portion 17, the auxiliary portion 17 can be suppressed from tilting with respect to the center axis line J when the auxiliary portion 17 tries to move downward.

[0097] By providing the screw 18, which is a pressing portion, at a position in contact with the receiving surface f3 in the recess portion 17b of the auxiliary portion 17, it is possible to increase the diameter (fitting diameter) between the protrusion portion 11d and the recess portion 17b as much as possible (within an allowable range). With such a configuration, the auxiliary portion 17 can be suppressed from tilting with respect to the center axis line J when the auxiliary portion 17 moves downward. Furthermore, the screw 18 is disposed on the center axis line J side relative to the fitting surface f4 between the protrusion portion 11d and the recess portion 17b, whereby the screw 18 is positioned at a place closed by fitting. Since the screw18 is disposed on the center axis line J side relative to the fitting surface f4, it is possible to prevent dust and foreign matters from being mixed into an engagement place of the screw 18. Use of the screw 18 as a pressing portion enables the auxiliary portion 17 to be suitably pressed against the first partition wall 16a.

[0098] As illustrated in FIGS. 2 and 13, the electric pump 100 of the present example embodiment includes the auxiliary portion 17 and a third partition wall 16c having a plate shape extending radially outward from the lower end portion of the second partition wall 16b to face the pump housing portion 20a at the second partition wall 16b having a tubular shape between the rotor 13 and the stator 15. By connecting the third partition wall 16c having a plate shape extending radially outward to the lower end portion of the second partition wall 16b having a tubular shape, the third partition wall 16c functions as a brim of a hat, and therefore shape stability of the second partition wall 16b is greatly improved. Improvement in the shape stability of the second partition wall 16b improves the rigidity (shape stability) of the entire partition wall portion 16. Improvement in the rigidity of the partition wall portion 16 can suppress the partition wall portion 16 from deforming even if receiving pressure at the time of sucking or discharging a fluid. Here, facing means that the surface of the partition wall is positioned in a state of being opposed to the target object, and is a concept including both a contact state and a non-contact state with respect to the target object (the same applies to the following partition wall).

[0099] In the present example embodiment, the fourth partition wall 16d has an annular shape extending on the other side in the axial direction from an outer circumferential edge portion of the third partition wall 16c to face the first housing 11 and / or the second housing 21. Further connecting the fourth partition wall 16d having an annular shape to the outer circumferential edge portion of the third partition wall 16c greatly improves the shape stability of not only the second partition wall 16b but also the third partition wall 16c, leading to further improvement in the rigidity (shape stability) of the entire partition wall portion 16.

[0100] In the present example embodiment, as illustrated in FIGS. 10 and 13, the step portion 21f is formed at the second opening portion 21a of the second housing 21. The fourth partition wall 16d faces the first wall surface 21g facing radially inward of the step portion 21f, and the third partition wall 16c faces the second wall surface 21h facing the other side in the axial direction (upper side) of the step portion 21f. That is, as illustrated in FIG. 13, parts (outer circumferential portions) of the fourth partition wall 16d and the third partition wall 16c are positioned so as to fit the step portion 21f. Since the fourth partition wall 16d and the third partition wall 16c are positioned so as to fit the step portion 21f, the lower side of the partition wall portion 16 can be supported from the housing H side, leading to improvement in the rigidity of the partition wall portion 16. Improvement in the rigidity can suppress the partition wall portion 16 from deforming even if receiving pressure at the time of sucking or discharging the fluid.

[0101] In the present example embodiment, as illustrated in FIGS. 5 and 6, the circumferential edge portion of the fourth partition wall 16d is provided with the fixing portion 16e extending radially outward. The fixing portion 16e can be fixed to the first housing 11 and / or the second housing 21. Since the lower side of the partition wall portion 16 is fixed to the housing H by fixing the fixing portion 16e to the first housing 11 and / or the second housing 21, the rigidity of the partition wall portion 16 is further improved. Fixing the fixing portion 16e to the first housing 11 and / or the second housing 21 can suppress deformation of the second partition wall 16b or the third partition wall 16c even if the second partition wall 16b and the third partition wall 16c receive pressure at the time of sucking or discharging the fluid.

[0102] In the present example embodiment, as illustrated in FIG. 13, the fixing portion 16e of the partition wall portion 16 is fixed by being sandwiched between the first surface 11n of the first opening portion 11k of the first housing 11 and the second surface 21n of the second opening portion 21a of the second housing 21. By sandwiching and fixing the first housing 11 and the second housing 21, it is possible to easily and suitably fix the fixing portion 16e to the housing H. As illustrated in FIGS. 2 and 7, by sandwiching this fixing portion 16e between the first surface 11n of the first opening portion 11k and the second surface 21n of the second opening portion 21a together with the O-ring 11j, it is possible to cause the fixing portion 16e to function as a gasket for sealing therebetween.

[0103] As illustrated in FIG. 7, the first partition wall 16a of the partition wall portion 16 is fixed to the shaft 12. The shaft 12 is fixed to the upper portion 11b of the first housing 11. Fixing the first partition wall 16a of the partition wall portion 16 to the shaft 12 fixed to the upper portion 11b of the first housing 11 improves the rigidity of not only the lower side of the partition wall portion 16 but also the upper side of the partition wall portion 16.

[0104] In the present example embodiment, as illustrated in FIG. 7, the auxiliary portion 17 is included between the upper portion 11b of the first housing 11 and the first partition wall 16a of the partition wall portion 16. This auxiliary portion 17 assists the first partition wall 16a so as to press it. Since the auxiliary portion 17 can press the first partition wall 16a, the rigidity of the partition wall portion 16 can be improved.

[0105] In the present example embodiment, as illustrated in FIG. 5, the reinforcing portion 16g continuous to the third partition wall 16c is included on the radially outer surface of the second partition wall 16b. This reinforcing portion 16g includes a reinforcing rib having a triangular shape as viewed from the circumferential direction in the present example embodiment. By reinforcing the connection portion between the second partition wall 16b and the third partition wall 16c by the reinforcing portion 16g, the positional relationship of the third partition wall 16c with respect to the second partition wall 16b is stabilized.

[0106] In the present example embodiment, as illustrated in FIG. 5, the plurality of reinforcing portions 16g are provided outside the second partition wall 16b along the circumferential direction of the second partition wall 16b. By providing the plurality of reinforcing portions 16g along the circumferential direction outside the second partition wall 16b, the positional relationship of the third partition wall 16c with respect to the second partition wall 16b is stabilized over the entire circumference of the second partition wall 16b.

[0107] In the present example embodiment, as illustrated in FIG. 5, the reinforcing rib 16g continuous to the third partition wall 16c is included on the radially outer surface of the second partition wall 16b. By reinforcing the connection portion between the second partition wall 16b and the third partition wall 16c by the reinforcing rib 16g, the positional relationship of the third partition wall 16c with respect to the second partition wall 16b is stabilized.

[0108] In the present example embodiment, as illustrated in FIG. 5, the reinforcing rib 16g has a triangular plate shape. The first side e1 extending axially is connected to the second partition wall 16b side, and the second side e2 extending radially is connected to the third partition wall 16c side. The first side e1 and the second side e2 are continuous by a hypotenuse. Therefore, the stress due to the fluid received by the second partition wall 16b can be received not only by the second partition wall 16b but also by the third partition wall 16c via the reinforcing rib 16g. Similarly, the stress due to the fluid received by the third partition wall 16c can be received not only by the third partition wall 16c but also by the second partition wall 16b via the reinforcing rib 16g. With such a configuration, the stress applied to the second partition wall 16b and the third partition wall 16c due to suction or discharge of the fluid can be dispersed, and the stress concentration on either one can be avoided, and therefore deformation of the partition wall portion 16 can be more suitably suppressed.

[0109] The example embodiment described above should be considered in all respects as illustrative and not restrictive. The scope of the present disclosure is defined not by the above-described example embodiment but by the claims, and it is intended to include all changes, modifications, and substitutions within the scope of equivalents of the claims. For example, the shapes of the first partition wall 16a of the partition wall portion 16 and the auxiliary portion 17 need not be a disk shape but may be a polygonal shape. The recess portion 17b of the auxiliary portion 17 and the protrusion portion 11d of the upper portion 11b to be fitted to the recess portion 17b may also have polygonal shapes.

[0110] The electric pump of the present disclosure can have the following configurations.

[0111] (1)

[0112] An electric pump including:

[0113] a shaft extending in axial direction;

[0114] a rotatable rotor positioned more toward an outer side in a radial direction than the shaft;

[0115] a stator surrounding the rotor and positioned more toward the outer side in the radial direction than the rotor;

[0116] a housing covering the stator and including an upper portion; and

[0117] a partition wall portion separating the rotor and the stator from each other, in which

[0118] the partition wall portion includes:

[0119] a first partition wall having a plate shape positioned on an upper side of the rotor and extending in the radial direction; and

[0120] a second partition wall having a tubular shape extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall; and

[0121] the electric pump further includes an auxiliary portion positioned between the upper portion and the first partition wall and in contact with the first partition wall.

[0122] (2)

[0123] The electric pump according to (1), in which the second partition wall includes a gap between the second partition wall and an inner diameter surface of the stator.

[0124] (3)

[0125] The electric pump according to (1), in which

[0126] the first partition wall includes a top surface opposing the upper portion side of the housing; and

[0127] the auxiliary portion includes a contact surface in contact with the top surface.

[0128] (4)

[0129] The electric pump according to (1), in which

[0130] the upper portion of the housing includes a pressing portion; and

[0131] the auxiliary portion is pressed on the first partition wall side by the pressing portion.

[0132] (5)

[0133] The electric pump according to (1), in which

[0134] a plurality of the pressing portions are included in a circumferential direction of a center axis line of the shaft.

[0135] (6)

[0136] The electric pump according to (1), in which

[0137] the upper portion of the housing includes a protrusion portion opposing the auxiliary portion side; and

[0138] the auxiliary portion includes a recess portion in which the protrusion portion is fitted.

[0139] (7)

[0140] The electric pump according to (4), in which the pressing portion is positioned at the upper portion of the housing on a center axis line side relative to a fitting surface between the protrusion portion and the recess portion.

[0141] (8)

[0142] The electric pump according to (4), in which the pressing portion is a screw.

[0143] (9)

[0144] An electric pump comprising:

[0145] a shaft extending in an axial direction;

[0146] a rotor located outward of the shaft in a radial direction and configured to be rotatable;

[0147] a stator located outward of the rotor in the radial direction and surrounding the rotor;

[0148] a first housing to accommodate the stator;

[0149] a pump portion located on one side of the rotor in the axial direction;

[0150] a second housing including a pump accommodating part configured to accommodate the pump portion; and

[0151] a partition wall portion configured to separate the rotor and the stator; wherein

[0152] the first housing includes an upper portion located on another side of the stator in the axial direction; and

[0153] the shaft is fixed to the upper portion.

[0154] (10)

[0155] The electric pump according to (9), in which the upper portion of the first housing includes a fixing hole; and

[0156] the shaft is press-fitted and fixed to the fixing hole.

[0157] (11)

[0158] The electric pump according to (9), in which the partition wall portion includes a penetration portion; and

[0159] the shaft penetrates through the penetration portion and is fixed to the upper portion of the first housing.

[0160] (12)

[0161] The electric pump according to (11), further comprising:

[0162] a seal portion configured to seal an area between the penetration portion and the shaft.

[0163] (13)The electric pump according to (11), in which

[0164] the partition wall portion includes a first partition wall having a plate shape, located on an upper side of the rotor, and extending in the radial direction; and

[0165] the penetration portion extends from the first partition wall toward the other side in the axial direction and is fitted with the shaft.

[0166] (14) An electric pump comprising:

[0167] a shaft extending axially;

[0168] a rotor rotatable and positioned radially outside relative to the shaft;

[0169] a stator surrounding the rotor and positioned radially outside the rotor;

[0170] a first housing covering the stator and including an upper portion fixing the shaft;

[0171] a pump assembly positioned on one side in the axial direction of the rotor;

[0172] a second housing including a pump housing portion housing the pump; and

[0173] a partition wall portion separating the rotor and the stator from each other; wherein

[0174] the partition wall portion includes:

[0175] a first partition wall having a plate shape positioned on another side in the axial direction of the rotor and extending radially;

[0176] a second partition wall having a tubular shape extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall; and

[0177] a third partition wall extending radially outward from an end portion on the one side in the axial direction of the second partition wall to face the pump housing portion.

[0178] (15)The electric pump according to (14) comprising a fourth partition wall having an annular shape extending on the other side in the axial direction from an outer circumferential edge portion of the third partition wall to face the first housing and / or the second housing.

[0179] (16)The electric pump according to (15), in which

[0180] the first housing includes a first opening portion opening toward the pump assembly;

[0181] the second housing includes a second opening portion opposing the first opening portion;

[0182] the second opening portion includes a step portion positioned on the one side in the axial direction relative to an edge portion of the second opening portion;

[0183] the fourth partition wall opposes a first wall surface opposing radially inward of the step portion, and

[0184] the third partition wall opposes a second wall surface opposing the other side in the axial direction of the step portion.

[0185] (17)The electric pump according to (15) comprising:

[0186] a fixing portion further extending radially outward from a circumferential edge portion of the fourth partition wall;

[0187] wherein

[0188] the fixing portion is fixed to the first housing and / or the second housing.

[0189] (18)The electric pump according to (17), wherein the fixing portion is fixed by being sandwiched between a first surface positioned at an edge portion of the first opening portion and a second surface positioned at an edge portion of the second opening portion.

[0190] (19)The electric pump according to (14), wherein the first partition wall is fixed to the shaft.

[0191] (20)The electric pump according to (14), comprising a reinforcing portion continuous to the third partition wall on a radially outer surface of the second partition wall.

[0192] Features of the above-described example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

[0193] While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Claims

1. An electric pump comprising:a shaft extending in axial direction;a rotatable rotor positioned more toward an outer side in a radial direction than the shaft;a stator surrounding the rotor and positioned more toward the outer side in the radial direction than the rotor;a housing covering the stator and including an upper portion; anda partition wall portion separating the rotor and the stator from each other; whereinthe partition wall portion includes:a first partition wall having a plate shape positioned on an upper side of the rotor and extending in the radial direction; anda second partition wall having a tubular shape extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall; andthe electric pump further includes an auxiliary portion positioned between the upper portion and the first partition wall and in contact with the first partition wall.

2. The electric pump according to claim 1, wherein the second partition wall includes a gap between the second partition wall and an inner diameter surface of the stator.

3. The electric pump according to claim 1, whereinthe first partition wall includes a top surface opposing the upper portion side of the housing; andthe auxiliary portion includes a contact surface in contact with the top surface.

4. The electric pump according to claim 1, whereinthe upper portion of the housing includes a pressing portion; andthe auxiliary portion is pressed on the first partition wall side by the pressing portion.

5. The electric pump according to claim 4, wherein a plurality of the pressing portions are included in a circumferential direction of a center axis line of the shaft.

6. The electric pump according to claim 1, whereinthe upper portion of the housing includes a protrusion portion opposing the auxiliary portion side; andthe auxiliary portion includes a recess portion in which the protrusion portion is fitted.

7. The electric pump according to claim 4, wherein the pressing portion is positioned at the upper portion of the housing on a center axis line side relative to a fitting surface between the protrusion portion and the recess portion.

8. The electric pump according to claim 4, wherein the pressing portion is a screw.

9. An electric pump comprising:a shaft extending in an axial direction;a rotor located outward of the shaft in a radial direction and configured to be rotatable;a stator located outward of the rotor in the radial direction and surrounding the rotor;a first housing to accommodate the stator;a pump portion located on one side of the rotor in the axial direction;a second housing including a pump accommodating part configured to accommodate the pump portion; anda partition wall portion configured to separate the rotor and the stator; whereinthe first housing includes an upper portion located on another side of the stator in the axial direction; andthe shaft is fixed to the upper portion.

10. The electric pump according to claim 9, whereinthe upper portion of the first housing includes a fixing hole; andthe shaft is press-fitted and fixed to the fixing hole.

11. The electric pump according to claim 9, whereinthe partition wall portion includes a penetration portion; andthe shaft penetrates through the penetration portion and is fixed to the upper portion of the first housing.

12. The electric pump according to claim 11, further comprising:a seal portion to seal an area between the penetration portion and the shaft.

13. The electric pump according to claim 11, whereinthe partition wall portion includes a first partition wall having a plate shape, located on an upper side of the rotor, and extending in the radial direction; andthe penetration portion extends from the first partition wall toward another side in the axial direction and is fitted with the shaft.

14. An electric pump comprising:a shaft extending axially;a rotor rotatable and positioned radially outside relative to the shaft;a stator surrounding the rotor and positioned radially outside the rotor;a first housing covering the stator and having an upper portion fixing the shaft;a pump assembly positioned on one side in the axial direction of the rotor;a second housing including a pump housing portion housing the pump; anda partition wall portion separating the rotor and the stator from each other; whereinthe partition wall portion includes:a first partition wall having a plate shape positioned on the other side in the axial direction of the rotor and extending radially;a second partition wall having a tubular shape extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall; anda third partition wall extending radially outward from an end portion on the one side in the axial direction of the second partition wall to oppose the pump housing portion.

15. The electric pump according to claim 14 comprising a fourth partition wall having an annular shape extending on the other side in the axial direction from an outer circumferential edge portion of the third partition wall to oppose the first housing and / or the second housing.

16. The electric pump according to claim 15, whereinthe first housing includes a first opening portion opening toward the pump assembly;the second housing includes a second opening portion opposing the first opening portion;the second opening portion includes a step portion positioned on the one side in the axial direction relative to an edge portion of the second opening portion;the fourth partition wall faces a first wall surface opposing radially inward of the step portion; andthe third partition wall opposes a second wall surface opposing the other side in the axial direction of the step portion.

17. The electric pump according to claim 15 comprisinga fixing portion further extending radially outward from a circumferential edge portion of the fourth partition wall; whereinthe fixing portion is fixed to the first housing and / or the second housing.

18. The electric pump according to claim 17, wherein the fixing portion is fixed by being sandwiched between a first surface positioned at an edge portion of the first opening portion and a second surface positioned at an edge portion of the second opening portion.

19. The electric pump according to claim 14, wherein the first partition wall is fixed to the shaft.

20. The electric pump according to claim 14, comprising a reinforcing portion continuous to the third partition wall on a radially outer surface of the second partition wall.

Images