JP7463775B2 - Electric pump - Google Patents

Description

The present invention relates to an electric pump.

Conventionally, electric pumps are known that house a motor, a pump mechanism, and a control board that controls the motor in a pump body.

Japanese Patent No. 5969342

In an electric pump, the member that closes the opening of the pump body has a sealing structure to prevent the intrusion of water and dust. Therefore, when multiple members are placed in one opening of the pump body, the structure is likely to become complicated. For example, a bus bar unit, bearing holder, and motor cover are placed in the opening of the motor housing that houses the motor. These members are connected to other members or fixed to the housing, and then stacked in the axial direction. Furthermore, sealing members must be installed where necessary. This can easily make the assembly work complicated.

According to one aspect of the present invention, an electric pump is provided that includes a motor having a rotor that can rotate around a central axis, a pump mechanism connected to one axial side of the motor, a motor housing that houses the motor and has an opening facing the other axial side, and a motor cover that closes the opening of the motor housing. The motor has a stator that faces the rotor in the radial direction, and a busbar unit that is located on the other axial side of the stator. The busbar unit has a first support portion that contacts the stator or the motor housing in the axial direction, and a second support portion that faces a surface of the motor cover facing the one axial side via an elastic member and compresses the elastic member between the motor cover and the busbar unit.

According to one aspect of the present invention, an electric pump with excellent assembly workability is provided.

FIG. 1 is a cross-sectional view of an electric pump according to an embodiment. FIG. 2 is a cross-sectional view of the electric pump according to the embodiment. FIG. 3 is an exploded perspective view of the electric pump according to the embodiment. FIG. 4 is a cross-sectional view of the electric pump of the first modified example. FIG. 5 is a cross-sectional view of an electric pump according to a second modified example.

The following describes an electric oil pump as an embodiment of an electric pump. The electric oil pump of the embodiment is used to supply oil to equipment mounted on a vehicle, etc.

In the drawings referred to below, an XYZ coordinate system is appropriately shown as a three-dimensional Cartesian coordinate system. In the XYZ coordinate system, the X-axis direction is parallel to the axis of the central axis J shown in FIG. 1. The central axis J is the central axis of the shaft 21 of the motor 20 described below. The Y-axis direction is a direction perpendicular to the X-axis, parallel to the depth direction in FIG. 1. The Z-axis direction is a direction perpendicular to both the X-axis and Y-axis directions, and parallel to the up-down direction in FIG. 1. In all of the X-axis, Y-axis, and Z-axis directions, the side toward which the arrows shown in the drawings point is the + side, and the opposite side is the - side.

In the following description, unless otherwise specified, the direction parallel to the central axis J (X-axis direction) is simply referred to as the "axial direction." The radial direction centered on the central axis J is simply referred to as the "radial direction." The circumferential direction centered on the central axis J, i.e., around the axis of the central axis J (θ direction), is simply referred to as the "circumferential direction."

The positive side (+X side) in the X-axis direction may be referred to as the "front side." Similarly, the negative side (-X side) in the X-axis direction may be referred to as the "rear side." The front side (+X side) corresponds to one axial side in this invention. The rear side (-X side) corresponds to the other axial side in this invention.

As shown in FIGS. 1 and 2 , an electric oil pump 100 of the present embodiment includes a pump body 10 , a motor 20 , a pump mechanism 30 , and a board unit 140 having a control board 40 .
The pump body 10 has a motor housing 11 that houses the motor 20, a pump housing 12 that houses the pump mechanism 30, and a board housing 13 on which a control board 40 is installed. In this embodiment, the motor housing 11, the pump housing 12, and the board housing 13 are part of a single member.

The motor housing 11 is located on the rear side (-X side) of the pump body 10. The motor housing 11 is cylindrical and extends in the axial direction. The motor housing 11 has a first accommodating recess 11a that is a recess that opens to the rear side. The first accommodating recess 11a is closed from the rear side by a bearing holder 26, which will be described later.

The pump housing 12 is located on the front side (+X side) of the pump body 10. The pump housing 12 has a second accommodating recess 12a that is a recess that opens to the front side. The electric oil pump 100 has a pump cover 12b that covers the second accommodating recess 12a from the front side. The pump cover 12b is a circular plate-shaped member when viewed from the axial direction. The pump cover 12b is screwed to the pump housing 12.

The board housing 13 is located on the side of the motor housing 11 and the pump housing 12. The board housing 13 is located on the illustrated lower side (-Z side) of the motor housing 11 and the pump housing 12. The board housing 13 is roughly rectangular when viewed from the radial outside. The board housing 13 has a third accommodating recess 13a that opens toward the illustrated lower side of the pump body 10. The board unit 140, which will be described later, is attached to the board housing 13 from the illustrated lower side.

The pump body 10 has a first through hole 10a and a second through hole 10b inside. The first through hole 10a axially connects the first accommodating recess 11a of the motor housing 11 to the second accommodating recess 12a of the pump housing 12. The second through hole 10b radially connects the first accommodating recess 11a of the motor housing 11 to the third accommodating recess 13a of the base housing 13.

The motor 20 includes a rotor 22 having a shaft 21, a stator 23, a busbar unit 120, a bearing holder 26, a first bearing 27, and a second bearing 28. The busbar unit 120 includes a busbar assembly 24 and a busbar cover 25. The bearing holder 26 covers the opening of the motor housing 11. In this embodiment, the bearing holder 26 also serves as the motor cover.

The shaft 21 is a cylindrical member extending along the central axis J. As shown in FIG. 2, the rotor 22 has the shaft 21, a rotor core 22a fixed to the outer circumferential surface of the shaft 21, and a plurality of rotor magnets 22b fixed to the rotor core 22a. The rotor magnets 22b may be annular magnets that surround the shaft 21.

The shaft 21 is supported by a first bearing 27 and a second bearing 28 so that it can rotate about its axis. The first bearing 27 supports a portion of the shaft 21 that is rearward of the rotor core 22a. The second bearing 28 supports a portion of the shaft 21 that is frontward of the rotor core 22a. The shaft 21 protrudes to the front side through the inner hole of the second bearing 28. The front end of the shaft 21 is connected to the pump mechanism 30.

The stator 23 includes an annular stator core 23a that surrounds the rotor 22, an insulator 23b that is attached to the teeth of the stator core 23a, and a coil 23c that is wound around the teeth via the insulator 23b. The stator core 23a is fixed to the inner circumferential surface of the cylindrical motor housing 11.

The busbar unit 120 is located between the stator 23 and the bearing holder 26. The busbar unit 120 has a busbar assembly 24 and a busbar cover 25 arranged side by side in the axial direction. The busbar assembly 24 faces the stator 23 in the axial direction. The busbar cover 25 faces the bearing holder 26 in the axial direction.

As shown in Figures 2 and 3, the busbar assembly 24 has busbars 24a, 24b, and 24c, and a resin busbar holder 24d that holds the busbars 24a to 24c. The three busbars 24a to 24c are insert molded into the busbar holder 24d. The busbars 24a to 24c may be fixed by screws, welding, or a snap fit.

As shown in FIG. 1, the busbar assembly 24 is located on the rear side of the stator 23. The busbar assembly 24 is inserted into the first accommodating recess 11a of the motor housing 11 from the rear side. One end of each of the three busbars 24a to 24c is hook-shaped. The hook-shaped ends of the busbars 24a, 24b, and 24c are each connected to the coil wire 23d extending from the coil 23c to the rear side. The other ends of the busbars 24a to 24c are located at the end of the busbar holder 24d on the board housing 13 side (the lower side in the figure). The ends of the busbars 24a, 24b, and 24c located at the bottom of the busbar holder 24d are each connected to the joint busbars 51a, 51b, and 51c described below.

The busbar cover 25 is located on the rear side of the busbar assembly 24. The busbar cover 25 is inserted into the first accommodating recess 11a from the rear side. The busbar cover 25 is annular when viewed from the axial direction. The busbar cover 25 covers the busbar assembly 24 from the rear side. The busbar cover 25 has a groove portion 25a that is annular when viewed from the axial direction on the surface facing the rear side. An elastic member 25b made of an O-ring is arranged inside the groove portion 25a.

The bearing holder 26 is located on the rear side of the busbar unit 120. The bearing holder 26 has a cylindrical portion 26a extending along the central axis J, and a holder body 26b extending radially outward from the outer circumferential surface of the cylindrical portion 26a. The cylindrical portion 26a opens on both sides in the axial direction. The first bearing 27 is inserted into the opening on the front side of the cylindrical portion 26a. The cylindrical portion 26a has a stepped surface 26c on part of its inner circumferential surface that faces the front side. Movement of the first bearing 27 to the rear side is restricted by the stepped surface 26c.

The bearing holder 26 extends radially outward from the busbar unit 120. The bearing holder 26 covers the busbar unit 120 from the rear side. The bearing holder 26 is screwed to the pump body 10 on the radially outer side of the busbar unit 120. The surface of the bearing holder 26 facing the front side is axially opposite the surface of the busbar cover 25 facing the rear side.

As shown in Figures 2 and 3, the bearing holder 26 has a seal area 26A on its front-facing surface, which is a flat surface that is annular when viewed from the axial direction. The motor housing 11 has a groove 26d on its end surface surrounding the first accommodating recess 11a, which opens toward the rear side. The groove 26d is annular when viewed from the axial direction. A seal member 29 made of an O-ring is disposed inside the groove 26d. The seal member 29 hermetically seals the gap between the seal area 26A of the bearing holder 26 and the end surface 11A of the opening of the motor housing 11.

When the bearing holder 26 blocks the first housing recess 11a from the rear side, the elastic member 25b is sandwiched between the bearing holder 26 and the bus bar cover 25 in the axial direction. The elastic member 25b is compressed in the axial direction by the bus bar cover 25 and the bearing holder 26. The elastic member 25b exerts an elastic force on the bus bar cover 25 and the bearing holder 26, moving them away from each other in the axial direction. Because the bearing holder 26 is fixed to the motor housing 11, the elastic return force of the elastic member 25b acts in a direction that pushes the bus bar cover 25 toward the front side.

The busbar cover 25 functions as a spacer inserted between the busbar assembly 24 and the bearing holder 26. The busbar cover 25 is pushed to the front side by the elastic member 25b, thereby pushing the busbar assembly 24 to the front side. The front end 24e of the busbar assembly 24 abuts against the step surface 11b facing the rear side of the motor housing 11. With this configuration, the busbar assembly 24 and the busbar cover 25 are fixed in the axial direction. The end 24e of the busbar assembly 24 may abut against the stator 23. By providing the busbar cover 25 as a spacer, the elastic member 25b is compressed uniformly in the circumferential direction. This makes the force pushing the busbar assembly 24 uniform in the circumferential direction. The busbar assembly 24 can be stably fixed.

As described above, in the busbar unit 120 of the present embodiment, the busbar assembly 24 has the first support portion 121 that is in axial contact with the stator 23 or the motor housing 11. In the case of the present embodiment, the first support portion 121 is the end portion 24e of the busbar assembly 24.
The bus bar cover 25 also has a second support portion 122 that faces a seal area 26A of the bearing holder 26 (motor cover) via an elastic member 25b and compresses the first seal member between the bus bar cover 25 and the bearing holder 26 .

According to the above configuration, with the busbar unit 120 accommodated in the first accommodation recess 11a of the motor housing 11, simply by fixing the bearing holder 26 to the motor housing 11, the busbar unit 120 can be stably fixed between the bearing holder 26 and the stator 23. Since there is no need to fasten the busbar unit 120 to the motor housing 11 or the stator 23, the assembly workability of the electric oil pump 100 is improved.

In addition, the busbar unit 120 does not require a mechanism for fixing it to the motor housing 11, so the diameter of the busbar unit 120 can be reduced. This allows the diameter of the motor housing 11 to be reduced, and the electric oil pump 100 to be made smaller.

In this embodiment, an elastic member 25b made of an O-ring is used. With this configuration, elastic force is applied uniformly in the circumferential direction to the bearing holder 26 and the bus bar cover 25. In addition, when assembling the electric oil pump 100, the worker can easily install the elastic member 25b on the bus bar cover 25.

The elastic member 25b may be an elastic member other than an O-ring. For example, the elastic member 25b may be configured to have a plurality of hemispherical or frustum-shaped elastic bodies arranged in the circumferential direction around the central axis J. Furthermore, the elastic member 25b may be a spring. For example, the elastic member 25b may be a coil spring, a leaf spring, or the like arranged between the bus bar cover 25A and the bearing holder 26, and the elastic force of the coil spring or leaf spring may be applied in the axial direction. When the type or shape of the elastic member 25b is changed, the shape of the groove portion 25a is also changed to match the aspect of the elastic member 25b.

In this embodiment, the busbar unit 120 has a first member (busbar assembly 24) and a second member (busbar cover 25) arranged side by side in the axial direction. By configuring the busbar unit 120 from two members, it becomes easier to design the first member, which has the function of holding the busbar, and the second member, which functions as a spacer inside the motor housing 11, in the optimal shape. Furthermore, the workability of connecting the busbar and the coil is improved, particularly in the first member, the busbar assembly 24.

The busbar unit 120 may be a member in which the busbar cover 25 and the busbar assembly 24 are fixed together. For example, the busbar cover 25 and the busbar holder 24d may be configured as part of a single component. The busbar cover 25 and the busbar assembly 24 may be connected together by a method such as gluing, welding, or screwing.

In this embodiment, as shown in FIG. 2, the seal area 26A of the bearing holder 26 faces the rear-facing surface of the busbar cover 25 via the elastic member 25b, and faces the end surface 11A of the opening of the motor housing 11 via the seal member 29. With this configuration, the elastic member 25b and the seal member 29 are arranged close to each other in the radial direction. Since the bearing holder 26 is screwed to the motor housing 11 just outside the seal member 29, the above configuration allows the elastic member 25b to be arranged close to the screw fastening portion that fixes the bearing holder 26. This makes it easier to apply a compressive force in the axial direction to the elastic member 25b. This allows the busbar unit 120 to be stably fixed in the motor housing 11. Since the seal area 26A can be formed in a single process, the manufacturing man-hours can be reduced.

A breather 26e is inserted into the rear end of the cylindrical portion 26a. That is, in the electric oil pump 100, the bearing holder 26, which functions as a motor cover, has the breather 26e. This configuration makes manufacturing easier and improves assembly workability compared to a configuration in which the breather 26e is installed in the motor housing 11.

The breather 26e allows air to flow between the inside and outside of the bearing holder 26. The inner space of the bearing holder 26 is connected to the inside of the first accommodating recess 11a via the cylindrical portion 26a. The first accommodating recess 11a is connected to the second accommodating recess 12a and the third accommodating recess 13a. Therefore, the breather 26e allows air to flow between the internal space of the pump body 10 and the external space.

In the electric oil pump 100, the bearing holder 26 that holds the first bearing 27 functions as a motor cover, making manufacturing easier and improving assembly workability compared to a configuration in which the motor cover and bearing holder are separate parts.
Furthermore, in the electric oil pump 100, the bearing holder 26, which functions as a motor cover, has a cylindrical portion 26a with a through hole that axially passes through the bearing holder 26, and holds a breather 26e at the rear end of the cylindrical portion 26a, and holds a first bearing 27 at the front end of the cylindrical portion 26a. With this configuration, the first bearing 27 and the breather 26e are aligned in the axial direction in the bearing holder 26, so that the space around the first bearing 27 inside the first accommodating recess 11a can be effectively utilized. This makes it possible to prevent the electric oil pump 100 from becoming large.

The second bearing 28 is inserted from the rear side into the first through hole 10a that connects the first accommodating recess 11a and the second accommodating recess 12a. Inside the first through hole 10a, the oil seal 15, the fixing ring 16, the wave washer 17, and the second bearing 28 are arranged in this order from the front side.

The first through hole 10a is a stepped hole having multiple steps inside. The first through hole 10a has a first step surface 10c and a second step surface 10d inside, both of which face the rear side. Therefore, the inner diameter of the first through hole 10a becomes smaller each time it passes through the steps toward the front side. The oil seal 15 is located between the first step surface 10c and the fixed ring 16 in the axial direction. The fixed ring 16 abuts against the second step surface 10d from the rear side. The fixed ring 16 supports the wave washer 17 with its surface facing the rear side. The wave washer 17 presses the outer ring of the second bearing 28 from the front side toward the rear side.

The shaft 21 passes through the inner holes of the second bearing 28, the wave washer 17, the fixing ring 16, and the oil seal 15. The front end of the shaft 21 passes through the first through hole 10a and reaches the second accommodating recess 12a.

The pump mechanism 30 has an inner rotor 31 connected to the front end of the shaft 21, and an outer rotor 32 surrounding the inner rotor 31 from the radially outer side. The inner rotor 31 and the outer rotor 32 are housed between the second housing recess 12a and the pump cover 12b. The inner rotor 31 and the outer rotor 32 each have a trochoid tooth profile. In other words, the pump mechanism 30 is a trochoid pump.

The board unit 140 includes a control board 40 and a board holder 141 that holds the control board 40 from the radial outside.

The board holder 141 is a box-shaped member that opens toward the board housing 13 (+Z side). The control board 40 is fixed to an opening of the board holder 141 that faces upward as shown in the figure. In this embodiment, the board holder 141 is made of resin. The board holder 141 has a connector 141b in which multiple metal terminals 141a are insert molded, and a busbar support portion 141c in which multiple joint busbars 51a to 51c are insert molded.

The multiple metal terminals 141a of the connector 141b are connected to the front end of the control board 40. The joint bus bars 51a to 51c are connected to the rear end of the control board 40.

The busbar support portion 141c is part of the board holder 141 and is made of resin. The busbar support portion 141c protrudes from the rear end of the board holder 141 towards the motor 20 (upper side in the figure). The joint busbars 51a to 51c extend from the connection position with the control board 40 towards the rear side and are inserted into the busbar support portion 141c. The joint busbars 51a to 51c extend radially inside the busbar support portion 141c and protrude from the tip of the busbar support portion 141c towards the motor 20.

The joint bus bars 51a to 51c connect the motor 20 and the control board 40. The joint bus bars 51a to 51c and the bus bar support portion 141c are inserted from the radially outer side into the second through hole 10b that connects the third accommodating recess 13a and the first accommodating recess 11a. The tips of the joint bus bars 51a to 51c are located within the first accommodating recess 11a and overlap with the bus bar assembly 24 when viewed from the axial direction. The joint bus bars 51a to 51c are screwed to the bus bars 24a to 24c of the bus bar assembly 24. This electrically connects the control board 40 and the motor 20 via the joint bus bars 51a to 51c.

The board unit 140 is fixed to the board housing 13 of the pump body 10 with the control board 40 facing the motor 20. In this embodiment, the board holder 141 of the board unit 140 is screwed to the board housing 13. The control board 40 is enclosed between the pump body 10 and the board holder 141.

In the electric oil pump 100 of this embodiment, the control board 40 is disposed along the side surface of the motor 20. The control board 40 has joint bus bars 51a, 51b, and 51c that are located inside the second through-hole 10b of the pump body 10 and electrically connect the motor 20 and the control board 40. With this configuration, the plate surface of the control board 40 faces in the radial direction, and the motor 20 and the control board 40 are connected in the radial direction by the joint bus bars 51a to 51c, so that the control board 40 does not protrude significantly in the radial direction. This makes it possible to prevent the electric oil pump 100 from becoming large in size.
Furthermore, the use of the joint bus bars 51a to 51c made of metal plate material facilitates connection inside the pump body 10. The electric oil pump 200 of this embodiment can be manufactured efficiently.

The electric oil pump 100 of this embodiment also includes a board unit 140 in which the control board 40, board holder 141, and joint bus bars 51a to 51c are assembled as a single component. With this configuration, the control board 40 can be attached by mounting the board unit 140 to the board housing 13 and connecting the joint bus bars 51a to 51c to the bus bars 24a to 24c. The electric oil pump 100 of this embodiment can be manufactured efficiently with few man-hours.

(Modification)
Within the scope of the present invention, the configurations (elements) described in the above-mentioned embodiments, variants, and notes may be combined, and addition, omission, substitution, and other modifications of the configurations are possible.

In the above embodiment, the elastic member 25b located between the busbar cover 25 and the bearing holder 26 is arranged in the groove portion 25a of the busbar cover 25, but the position of the elastic member 25b can be changed. Below, configurations in which the arrangement of the elastic member 25b is changed will be described as the first and second modified examples.

FIG. 4 is a partial cross-sectional view of the electric oil pump 100 showing a first modified example of the arrangement of the elastic member 25b.
The electric oil pump 100 of the first modified example includes a bus bar unit 120 A. The bus bar unit 120 A has a bus bar assembly 24 and a bus bar cover 25 A. The bus bar cover 25 A is located between the bus bar assembly 24 and the bearing holder 26.

The busbar cover 25A has a step portion 25c at the corner of the outer circumferential end of the surface facing the rear side (-X side). The step portion 25c is annular when viewed from the axial direction. The step portion 25c has a surface facing the rear side and a surface facing radially outward. An elastic member 25b made of an O-ring is disposed inside the step portion 25c.

In the first modified example, the elastic member 25b is also compressed in the axial direction between the busbar cover 25A and the bearing holder 26. The elastic return force of the elastic member 25b pushes the busbar cover 25A toward the front side. The busbar cover 25A pushes the busbar assembly 24 toward the front side. As a result, the busbar unit 120A consisting of the busbar cover 25A and the busbar assembly 24 is fixed between the bearing holder 26 and the stator 23.

FIG. 5 is a partial cross-sectional view of the electric oil pump 100 showing a second modified example of the arrangement of the elastic member 25b.
The electric oil pump 100 of the second modified example includes a bus bar unit 120B. The bus bar unit 120B has a bus bar assembly 24 and a bus bar cover 25B. The bus bar cover 25B is located between the bus bar assembly 24 and the bearing holder 26.

The busbar cover 25B has a tapered portion 25d at the corner of the outer circumferential end of the surface facing the rear side (-X side). The tapered portion 25d is annular when viewed from the axial direction. The tapered portion 25d has an inclined surface that slopes radially outward from the surface facing the rear side of the busbar cover 25B toward the front side. An elastic member 25b made of an O-ring is disposed at a position radially opposite the tapered portion 25d. In other words, the elastic member 25b is disposed in an area surrounded by the tapered portion 25d, the seal area 26A of the bearing holder 26, and the inner circumferential surface of the motor housing 11.

In the second modified example, the elastic member 25b is also compressed in the axial direction between the busbar cover 25B and the bearing holder 26. The elastic return force of the elastic member 25b pushes the busbar cover 25B toward the front side. The busbar cover 25B pushes the busbar assembly 24 toward the front side. As a result, the busbar unit 120B consisting of the busbar cover 25B and the busbar assembly 24 is fixed between the bearing holder 26 and the stator 23.

The first and second modified examples described above also provide the same effects as the electric oil pump 100 of the embodiment shown in Figures 1 to 3. In other words, the first and second modified examples improve the ease of assembly of the electric oil pump.

11...motor housing, 11A...end surface, 20...motor, 21...shaft, 22...rotor, 22a...rotor core, 23...stator, 24a-24c...busbar, 24e...end, 25a...groove, 25b...elastic member, 25c...step, 25d...tapered portion, 26e...breather, 26A...seal area, 29...seal member, 30...pump mechanism, 120, 120A, 120B...busbar unit, 121...first support, 122...second support, J...center axis

Claims (9)

A motor having a rotor that can rotate around a central axis;
a pump mechanism connected to one axial side of the motor;
a motor housing that houses the motor and has an opening facing the other axial direction;
a motor cover that closes an opening of the motor housing;
Equipped with
The motor is
a stator radially opposed to the rotor;
a bus bar assembly located on the other axial side of the stator;
a bus bar cover disposed between the motor cover and the bus bar assembly;
having
The busbar assembly includes:
A plurality of bus bars connected to the coils of the stator;
a bus bar holder for holding a plurality of the bus bars;
the bus bar holder has a first support portion that contacts the other axial side of the stator or the motor housing,
The bus bar cover is
a second support portion that faces a surface of the motor cover facing one axial side via an elastic member and compresses the elastic member between the motor cover and the second support portion , and presses the bus bar assembly toward the one axial side;
Electric pump. The elastic member is an O-ring.
The second support portion has a groove portion that opens toward the other axial side and holds the O-ring.
The electric pump according to claim 1 . The elastic member is an O-ring.
The second support portion is a tapered portion or a stepped portion located at an outer circumferential end of an end surface on the other axial side of the bus bar cover .
The electric pump according to claim 1 . The elastic member is a spring located between the motor cover and the second support portion in the axial direction.
The electric pump according to claim 1 . the motor cover has a seal area formed of an annular flat surface as viewed in the axial direction on a surface facing one axial direction,
the seal area faces the second support portion of the bus bar cover via the elastic member, and faces an end surface of the opening of the motor housing via a seal member.
The electric pump according to any one of claims 1 to 4 . The motor cover has a breather.
The electric pump according to any one of claims 1 to 5 . The rotor has a shaft extending along a central axis and a rotor core fixed to the shaft,
The motor cover has a bearing holder that holds a bearing that supports the shaft.
The electric pump according to any one of claims 1 to 6 . the motor cover has a through hole passing through the motor cover in an axial direction,
the motor cover holds a bearing at one axial end of the through hole, and holds a breather at the other axial end of the through hole.
The electric pump according to any one of claims 1 to 5 . The bus bar cover has a cylindrical shape extending along an axial direction,
The bearing holding portion is located radially inside the bus bar cover .
The electric pump according to claim 7 .

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