CN215009779U

CN215009779U - Electric pump

Info

Publication number: CN215009779U
Application number: CN202120504973.4U
Authority: CN
Inventors: 片冈慈裕; 小林喜幸
Original assignee: Nidec Tosok Corp
Current assignee: Nidec Powertrain Systems Corp
Priority date: 2020-03-13
Filing date: 2021-03-10
Publication date: 2021-12-03
Anticipated expiration: 2031-03-10
Also published as: JP7463775B2; JP2021143660A

Abstract

An electric pump comprising: a motor having a rotor rotatable about a central axis; a pump mechanism coupled to one axial side of the motor; a motor housing which houses the motor and has an opening portion facing the other side in the axial direction; and a motor cover for closing the opening of the motor housing. The motor includes: a stator facing the rotor in a radial direction; and a bus bar unit located at the other axial side of the stator. The bus bar unit includes: a first support part axially contacting the stator or the motor housing; and a second support part which faces the surface of the motor cover facing one side in the axial direction through an elastic member and compresses the elastic member between the second support part and the motor cover. The utility model discloses an electric pump, equipment operation nature is excellent.

Description

Electric pump

Technical Field

The utility model relates to an electric pump.

Background

Conventionally, as an electric pump, a structure is known in which a motor, a pump mechanism, and a control board for controlling the motor are housed in a pump body.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent No. 5969342 publication

SUMMERY OF THE UTILITY MODEL

[ problem to be solved by the utility model ]

In the electric pump, a member for closing an opening portion of a pump body has a seal structure for preventing intrusion of water and dust. Therefore, when a plurality of members are disposed in one opening portion of the pump body, the structure is easily complicated. For example, a bus bar unit, a bearing holder, and a motor cover are disposed in an opening of a motor case that houses a motor. These components are stacked in the axial direction after being connected with other components or fixed to the housing. Further, a seal member needs to be provided at a desired portion. This makes the assembly work easy to be complicated.

[ means for solving problems ]

According to an embodiment of the present invention, there is provided an electric pump, including: a motor having a rotor rotatable about a central axis; a pump mechanism coupled to one axial side of the motor; a motor housing that houses the motor and has an opening portion facing the other side in the axial direction; and a motor cover for closing the opening of the motor housing. The motor includes: a stator facing the rotor in a radial direction; and a bus bar unit located at the other axial side of the stator. The bus bar unit includes: a first support portion axially contacting the stator or the motor housing; and a second support portion that faces the surface of the motor cover facing one axial side via an elastic member and compresses the elastic member between the second support portion and the motor cover.

According to an embodiment of the present invention, the bus bar unit includes a first member and a second member arranged in an axial direction, the first member includes the first support portion, and the second member is located on the other axial side of the first member and includes the second support portion.

According to an embodiment of the present invention, the elastic member is an O-ring, and the second support portion has a groove portion that is open toward the other axial side and holds the O-ring.

According to an embodiment of the present invention, the elastic member is an O-ring, and the second support portion is a tapered portion or a stepped portion located at an outer peripheral end of the end surface of the other axial side of the bus bar unit.

According to an embodiment of the present invention, the elastic member is a spring located between the motor cover and the second support portion in the axial direction.

According to an embodiment of the present invention, the motor cover has a seal region on a surface facing one side in the axial direction, the seal region includes a flat surface which is annular when viewed in the axial direction, and the seal region faces the second support portion of the bus bar unit via the elastic member and faces an end surface of the opening portion of the motor housing via the seal member.

According to an embodiment of the present invention, the motor cover has an air vent.

According to an embodiment of the present invention, the motor pump further includes a motor cover that is provided with a shaft extending along the center axis and a rotor core fixed to the shaft, and the motor cover has a bearing holding portion that holds a bearing that supports the shaft.

According to an embodiment of the present invention, the motor cover has a through hole penetrating the motor cover in the axial direction, and the motor cover holds the bearing at an end portion of one side in the axial direction of the through hole and holds the breather at an end portion of the other side in the axial direction of the through hole.

According to an embodiment of the present invention, the bus bar unit is a tubular shape extending in the axial direction, and the bearing holding portion is located radially inside the bus bar unit.

[ effects of the utility model ]

According to an embodiment of the present invention, there is provided an electric pump having excellent assembly workability.

Drawings

Fig. 1 is a sectional view of an electric pump of the embodiment.

Fig. 2 is a sectional view of the electric pump of the embodiment.

Fig. 3 is an exploded perspective view of the electric pump of the embodiment.

Fig. 4 is a sectional view of an electric pump according to a first modification.

Fig. 5 is a sectional view of an electric pump according to a second modification.

[ description of reference numerals ]

11: motor shell

11A: end face

20: motor with a stator having a stator core

21: shaft

22: rotor

22 a: rotor core

23: stator

24a to 24 c: bus bar

24 e: end part

25 a: trough part

25 b: elastic member

25 c: step difference part

25 d: tapered portion

26 e: ventilation device

26A: sealing area

29: sealing member

30: pump mechanism

120. 120A, 120B: bus bar unit

121: a first supporting part

122: second supporting part

J: center shaft

Detailed Description

Hereinafter, the electric oil pump will be described as an embodiment of the electric pump. The electric oil pump of the embodiment is used for supplying oil to equipment mounted on a vehicle or the like.

Hereinafter, an XYZ coordinate system is shown as a suitable three-dimensional orthogonal coordinate system in each of the drawings to be referred to. In the XYZ coordinate system, the X-axis direction is a direction parallel to the axial direction of the central axis J shown in fig. 1. The center axis J is a center axis of a shaft 21 of the motor 20 described later. The Y-axis direction is a direction parallel to the depth direction in fig. 1 among directions orthogonal to the X-axis. The Z-axis direction is a direction orthogonal to both the X-axis direction and the Y-axis direction, and is a direction parallel to the vertical direction in fig. 1. In any one of the X-axis direction, the Y-axis direction, and the Z-axis direction, one side indicated by an arrow shown in the drawing is set as a + side, and the opposite side is set as a-side.

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

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

As shown in fig. 1 and 2, the electric oil pump 100 of the present embodiment includes: pump body 10, motor 20, pump mechanism 30, and base plate unit 140 having control base plate 40.

The pump body 10 includes a motor housing 11 that houses the motor 20, a pump housing 12 that houses the pump mechanism 30, and a substrate housing 13 on which the control substrate 40 is provided. In the present embodiment, the motor housing 11, the pump housing 12, and the substrate housing 13 are parts of separate members.

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 housing recess 11a including a recess opening toward the rear side. The first housing recess 11a is closed from the rear side by a bearing holder 26 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 housing recess 12a including a recess opening to the front side. The electric oil pump 100 has a pump cover 12b, and the pump cover 12b closes the second receiving recess 12a from the front side. The pump cover 12b is a circular plate-shaped member as viewed in the axial direction. The pump cover 12b is screwed to the pump housing 12.

The substrate case 13 is located on the side of the motor case 11 and the pump case 12. The substrate case 13 is located below (on the Z side) of the motor case 11 and the pump case 12. The substrate case 13 has a substantially rectangular shape as viewed from the radially outer side. The substrate case 13 has a third housing recess 13a that opens toward the lower side of the pump body 10. A substrate unit 140 described later is attached to the substrate case 13 from the lower side in the drawing.

The pump body 10 has a first through hole 10a and a second through hole 10b therein. The first through hole 10a axially connects the first receiving recess 11a of the motor housing 11 and the second receiving recess 12a of the pump housing 12. The second through hole 10b connects the first accommodating recess 11a of the motor housing 11 and the third accommodating recess 13a of the substrate housing 13 in the radial direction.

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

The shaft 21 is a columnar member extending along the center axis J. As shown in fig. 2, the rotor 22 includes: shaft 21, rotor core 22a fixed to the outer peripheral surface of shaft 21, and a plurality of rotor magnets 22b fixed to rotor core 22 a. The rotor magnet 22b may be an annular magnet surrounding the shaft 21.

The shaft 21 is supported rotatably around the shaft by a first bearing 27 and a second bearing 28. The first bearing 27 supports a portion of the shaft 21 on the rear side of the rotor core 22 a. The second bearing 28 supports a portion of the shaft 21 on the front side of the rotor core 22 a. 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 a pump mechanism 30.

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

The bus bar unit 120 is located between the stator 23 and the bearing bracket 26. The busbar unit 120 includes a busbar assembly 24 and a busbar cover 25 arranged in an axial direction. The bus bar assembly 24 is axially opposed to the stator 23. The bus bar cover 25 faces the bearing bracket 26 in the axial direction.

As shown in fig. 2 and 3, the bus bar assembly 24 includes: the bus bar 24a, the bus bar 24b, the bus bar 24c, and a resin bus bar holder 24d holding the bus bars 24a to 24 c. The three bus bars 24a to 24c are insert-molded in the bus bar holder 24 d. The fixing method of the bus bars 24a to 24c may be screwing, welding, or snap-fitting.

As shown in fig. 1, the bus bar assembly 24 is located at the rear side of the stator 23. The bus bar assembly 24 is inserted into the first receiving recess 11a of the motor housing 11 from the rear side. One end of each of the three bus bars 24a to 24c has a hook shape. The hook-shaped end portions of the

bus bars

24a, 24b, and 24c are connected to coil wires 23d extending rearward from the coil 23 c. The other end portions of the bus bars 24a to 24c are positioned at the end portion of the bus bar holder 24d on the substrate case 13 side (lower side in the drawing). The ends of the

bus bars

24a, 24b, and 24c positioned below the bus bar holder 24d are connected to a joint bus bar 51a, a joint bus bar 51b, and a joint bus bar 51c, respectively, which will be described later.

The bus bar cover 25 is located at the rear side of the bus bar assembly 24. The busbar cover 25 is inserted into the first housing recess 11a from the rear side. The bus bar cover 25 is annular when viewed from the axial direction. The bus bar cover 25 covers the bus bar assembly 24 from the rear side. The bus bar cover 25 has an annular groove portion 25a on a surface facing the rear side in the axial direction. An elastic member 25b including an O-ring is disposed inside the groove portion 25 a.

The bearing bracket 26 is located on the rear side of the busbar unit 120. The bearing holder 26 includes a cylindrical portion 26a extending along the central axis J, and a holder main body 26b extending radially outward from the outer circumferential surface of the cylindrical portion 26 a. The cylindrical portion 26a is open on both sides in the axial direction. The first bearing 27 is inserted into an opening portion on the front side of the cylindrical portion 26 a. The cylindrical portion 26a has a stepped surface 26c facing the front side at a part of the inner peripheral surface. The movement of the first bearing 27 to the rear side is restricted by the step surface 26 c.

The bearing bracket 26 is expanded to the outside of the busbar unit 120 in the radial direction. The bearing bracket 26 covers the bus bar unit 120 from the rear side. The bearing holder 26 is screwed to the pump body 10 radially outside the busbar unit 120. The front surface of the bearing bracket 26 and the rear surface of the busbar cover 25 face each other in the axial direction.

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

The bearing holder 26 closes the first receiving recess 11a from the rear side, whereby the elastic member 25b is axially sandwiched between the bearing holder 26 and the busbar cover 25. The elastic member 25b is compressed in the axial direction by the busbar cover 25 and the bearing holder 26. The elastic member 25b applies an elastic force to the busbar cover 25 and the bearing holder 26 to separate the two in the axial direction. Since the bearing bracket 26 is fixed to the motor housing 11, the elastic restoring force of the elastic member 25b acts in a direction of pushing the bus bar cover 25 forward.

The busbar cover 25 functions as a spacer inserted between the busbar assembly 24 and the bearing bracket 26. The bus bar cover 25 is pressed to the front side by the elastic member 25b, and presses the bus bar assembly 24 to the front side. The front end 24e of the bus bar assembly 24 abuts on the stepped surface 11b of the motor housing 11 facing the rear side. According to this structure, the busbar assembly 24 and the busbar cover 25 are fixed in the axial direction. The end 24e of the bus bar assembly 24 may abut the stator 23. The elastic member 25b is uniformly compressed in the circumferential direction by including the bus bar cover 25 as a spacer. Thereby, the force pressing the bus bar assembly 24 becomes uniform in the circumferential direction. The bus bar assembly 24 can be stably fixed.

As described above, in the bus bar unit 120 of the present embodiment, the bus bar assembly 24 includes the first support portion 121 that is in contact with the stator 23 or the motor housing 11 in the axial direction. In the case of the present embodiment, the first support part 121 is the end 24e of the bus bar assembly 24.

The bus bar cover 25 has a second support portion 122 that faces the seal region 26A of the bearing holder 26 (motor cover) with the elastic member 25b interposed therebetween, and compresses the first seal member between the second support portion 122 and the bearing holder 26.

According to the above configuration, in a state where the bus bar unit 120 is accommodated in the first accommodation recess 11a of the motor housing 11, the bus bar unit 120 can be stably fixed between the bearing holder 26 and the stator 23 only by fixing the bearing holder 26 to the motor housing 11. Since it is not necessary to fasten the bus bar unit 120 to the motor housing 11 or the stator 23, the assembling workability of the electric oil pump 100 is improved.

In addition, the bus bar unit 120 does not require a mechanism for fixing to the motor housing 11, and therefore the diameter of the bus bar unit 120 can be reduced. This reduces the diameter of the motor housing 11, and the electric oil pump 100 can be reduced in size.

In the present embodiment, the elastic member 25b including an O-ring is used. According to this structure, the elastic force is uniformly applied to the bearing holder 26 and the busbar cover 25 in the circumferential direction. In addition, when assembling the electric oil pump 100, the operator can easily set 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 such that a plurality of hemispherical or frustoconical elastic bodies are arranged in the circumferential direction around the center axis J. The elastic member 25b may be a spring. For example, as the elastic member 25b, a coil spring, a leaf spring, or the like may be disposed between the bus bar cover 25 and the bearing holder 26, and an elastic force of the coil spring or the leaf spring may be applied in the axial direction. When the type or shape of the elastic member 25b is changed, the shape or the like of the groove portion 25a is also changed according to the form of the elastic member 25 b.

In the present embodiment, the busbar unit 120 includes a first member (busbar assembly 24) and a second member (busbar cover 25) arranged in an axial direction. By configuring the bus bar unit 120 to include two members, it is easy to design each of the first member having a function of holding the bus bar and the second member functioning as a spacer in the motor housing 11 in an optimal shape. In particular, in the bus bar assembly 24 as the first member, the workability of connection between the bus bar and the coil is improved.

The bus bar unit 120 may be a member to which the bus bar cover 25 and the bus bar assembly 24 are fixed. For example, the bus bar cover 25 and the bus bar holder 24d may be formed as a part of a separate component. The bus bar cover 25 and the bus bar assembly 24 can be joined by adhesion, welding, screwing, or the like.

In the present embodiment, as shown in fig. 2, the seal region 26A of the bearing holder 26 faces the surface of the bus bar cover 25 facing the rear side through the elastic member 25b, and faces the end surface 11A of the opening of the motor housing 11 through the seal member 29. According to this structure, the elastic member 25b and the seal member 29 are arranged close to each other in the radial direction. Since the bearing bracket 26 is fastened to the motor housing 11 with screws outside the vicinity of the seal member 29, the elastic member 25b is disposed in the vicinity of the screw fastening portion to which the bearing bracket 26 is fixed. This makes it easy to apply a force that compresses the elastic member 25b in the axial direction. This allows the bus bar unit 120 to be stably fixed in the motor case 11. Since the seal region 26A can be formed by one processing, the number of manufacturing steps can be reduced.

The breather 26e is inserted into the rear end of the cylindrical portion 26 a. That is, in the electric oil pump 100, the bearing holder 26 functioning as a motor cover has the breather device 26 e. With this configuration, manufacturing is facilitated and assembly workability is improved as compared with a configuration in which the breather device 26e is provided in the motor case 11.

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

In the electric oil pump 100, the bearing holder 26 for holding the first bearing 27 functions as a motor cover, and therefore, compared with a configuration in which the motor cover and the bearing holder are separate parts, the manufacturing is easy and the assembling workability is improved.

In the electric oil pump 100, the bearing holder 26 functioning as a motor cover has a cylindrical portion 26a, the cylindrical portion 26a has a through hole axially penetrating the bearing holder 26, a breather 26e is held at a rear end portion of the cylindrical portion 26a, and a first bearing 27 is held at a front end portion of the cylindrical portion 26 a. According to this configuration, in the bearing holder 26, the first bearing 27 and the breather 26e are axially aligned, and therefore, the space around the first bearing 27 can be effectively utilized inside the first accommodating recess 11 a. The electric oil pump 100 can be suppressed from being large-sized.

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

The first through-hole 10a is a stepped hole having a plurality of steps therein. The first through hole 10a has therein a first step surface 10c and a second step surface 10d both facing rearward. Therefore, the inner diameter of the first through-hole 10a becomes smaller as it goes to the front side, each time it passes the step. The oil seal 15 is located between the first step surface 10c and the fixed ring 16 in the axial direction. The fixing ring 16 abuts on the second step surface 10d from the rear side. The fixing ring 16 supports the wave washer 17 by a face toward the rear side. The wave washer 17 presses the outer race of the second bearing 28 from the front side toward the rear side.

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

The pump mechanism 30 includes an inner rotor 31 connected to a 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 accommodated between the second accommodation recess 12a and the pump cover 12 b. The inner rotor 31 and the outer rotor 32 have trochoid (trochoid) tooth profiles, respectively. That is, the pump mechanism 30 is a trochoid pump.

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

The substrate holder 141 is a box-shaped member that opens toward the substrate housing 13 side (+ Z side). The control board 40 is fixed to an opening of the board holder 141 facing upward in the figure. In the present embodiment, the substrate holder 141 is made of resin. The substrate holder 141 includes a connector 141b in which a plurality of metal terminals 141a are insert-molded, and a bus bar support 141c in which a plurality of tab bus bars 51a to 51c are insert-molded.

The plurality of 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 bus bar support 141c is a part of the substrate holder 141, and includes resin. The bus bar support 141c protrudes from the rear end of the substrate holder 141 toward the motor 20 (upper side in the figure). The tab bus bars 51a to 51c extend from the connection position with the control board 40 to the rear side, and are inserted into the bus bar support portion 141 c. The joint bus bars 51a to 51c extend in the radial direction within the bus bar support portion 141c, and protrude from the leading end of the bus bar support portion 141c toward the motor 20 side.

The joint bus 51a to 51c connect the motor 20 and the control board 40. The tab bus bars 51a to 51c and the bus bar supporting portion 141c are inserted from the radial outside into the second through hole 10b connecting the third accommodating recess 13a and the first accommodating recess 11 a. The tip ends of the joint bus bars 51a to 51c are positioned in the first receiving recess 11a, and overlap the bus bar assembly 24 as viewed in 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. Thereby, the control board 40 and the motor 20 are electrically connected via the joint bus 51a to the joint bus 51 c.

The substrate unit 140 is fixed to the substrate case 13 of the pump body 10 in a state where the control substrate 40 faces the motor 20 side. In the present embodiment, the substrate holder 141 of the substrate unit 140 is screwed to the substrate case 13. The control board 40 is enclosed between the pump body 10 and the board holder 141.

In the electric oil pump 100 of the present embodiment, the control board 40 is disposed along the side surface of the motor 20. Further, the pump body 10 includes a joint bus 51a, a joint bus 51b, and a joint bus 51c which are located inside the second through hole 10b and electrically connect the motor 20 and the control board 40. According to this configuration, the plate surface of the control board 40 is oriented in the radial direction, and the motor 20 and the control board 40 are connected in the radial direction by the joint bus bar 51a to the joint bus bar 51c, so that the control board 40 does not greatly protrude in the radial direction. Therefore, the electric oil pump 100 can be suppressed from being large.

Further, since the joint bus bars 51a to 51c made of a metal plate material are used, the connection inside the pump body 10 is facilitated. The electric oil pump 100 of the present embodiment can be manufactured efficiently.

The electric oil pump 100 of the present embodiment includes a substrate unit 140 in which the control substrate 40, the substrate holder 141, and the joint bus bars 51a to 51c are assembled as one component. With this configuration, the control board 40 can be mounted by attaching the board unit 140 to the board case 13 and connecting the tab bus 51a to the tab bus 51c and the bus bars 24a to the bus bars 24 c. The electric oil pump 100 of the present embodiment can be efficiently manufactured with a small number of steps.

(modification example)

The respective components (constituent elements) described in the above-described embodiments, modifications, comments, and the like may be combined, and addition, omission, replacement, and other changes of the components may be made without departing from the scope of the present invention.

In the above embodiment, the elastic member 25b positioned between the busbar cover 25 and the bearing holder 26 is disposed in the groove portion 25a of the busbar cover 25, but the position of the elastic member 25b may be changed. Hereinafter, a configuration in which the arrangement of the elastic member 25b is changed will be described as a first modification and a second modification.

Fig. 4 is a partial sectional view of the electric oil pump 100 showing a first modification of the arrangement of the elastic member 25 b.

The electric oil pump 100 of the first modification includes a bus bar unit 120A. The busbar unit 120A has a busbar assembly 24, and a busbar cover 25A. The busbar cover 25A is located between the busbar assembly 24 and the bearing bracket 26.

The bus bar cover 25A has a step portion 25c at a corner portion of the outer peripheral 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 rearward and a surface facing radially outward. An elastic member 25b including an O-ring is disposed inside the step portion 25 c.

In the first modification, the elastic member 25b is also compressed in the axial direction between the busbar cover 25A and the bearing holder 26. The bus bar cover 25A is pressed toward the front side due to the elastic restoring force of the elastic member 25 b. The bus bar cover 25A presses the bus bar assembly 24 to the front side. Thereby, the bus bar unit 120A including the bus bar cover 25A and the bus bar assembly 24 is fixed between the bearing bracket 26 and the stator 23.

Fig. 5 is a partial sectional view of the electric oil pump 100 showing a second modification of the arrangement of the elastic member 25 b.

The electric oil pump 100 of the second modification includes a bus bar unit 120B. The busbar unit 120B has a busbar assembly 24, and a busbar cover 25B. The busbar cover 25B is located between the busbar assembly 24 and the bearing bracket 26.

The busbar cover 25B has a tapered portion 25d at a corner portion of the outer peripheral end of the face toward 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 inclined radially outward from the surface of the bus bar cover 25B facing rearward toward the front side. An elastic member 25b including an O-ring is disposed at a position radially opposite to the tapered portion 25 d. That is, the elastic member 25b is disposed in a region surrounded by the tapered portion 25d, the seal region 26A of the bearing holder 26, and the inner peripheral surface of the motor housing 11.

In the second modification, the elastic member 25B is also compressed in the axial direction between the busbar cover 25B and the bearing holder 26. The bus bar cover 25B is pressed toward the front side due to the elastic restoring force of the elastic member 25B. The bus bar cover 25B presses the bus bar assembly 24 to the front side. Thereby, the bus bar unit 120B including the bus bar cover 25B and the bus bar assembly 24 is fixed between the bearing bracket 26 and the stator 23.

In the first modification and the second modification described above, the same operational effects as those of the electric oil pump 100 of the embodiment shown in fig. 1 to 3 can be obtained. That is, according to the first modification and the second modification, the assembling workability of the electric oil pump is improved.

Claims

1. An electric pump, comprising:

a motor having a rotor rotatable about a central axis;

a pump mechanism coupled to one axial side of the motor;

a motor housing that houses the motor and has an opening portion facing the other side in the axial direction; and

a motor cover for closing the opening of the motor housing,

the motor includes:

a stator facing the rotor in a radial direction; and

a bus bar unit located at the other axial side of the stator,

the bus bar unit includes:

a first support portion axially contacting the stator or the motor housing; and

and a second support portion that faces the surface of the motor cover facing one axial side via an elastic member and compresses the elastic member between the second support portion and the motor cover.

2. The electric pump of claim 1,

the bus bar unit has a first member and a second member arranged in an axial direction,

the first member has the first support portion,

the second member is located on the other axial side of the first member and has the second support portion.

3. The electric pump according to claim 1 or 2,

the resilient 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.

4. The electric pump according to claim 1 or 2,

the resilient member is an O-ring,

the second support portion is a tapered portion or a stepped portion located at an outer peripheral end of an end surface on the other axial side of the bus bar unit.

5. The electric pump according to claim 1 or 2,

the elastic member is a spring located between the motor cover and the second support portion in the axial direction.

6. The electric pump according to claim 1 or 2,

the motor cover has a sealing region on a face facing one side in the axial direction, the sealing region including a flat face that is annular as viewed in the axial direction,

the seal region faces the second support portion of the bus bar unit via the elastic member, and faces an end surface of the opening of the motor case via a seal member.

7. The electric pump according to claim 1 or 2,

the motor cover has a breather.

8. The electric pump according to claim 1 or 2,

the rotor has a shaft extending along a central axis and a rotor core fixed to the shaft,

the motor cover has a bearing holding portion that holds a bearing that supports the shaft.

9. The electric pump of claim 7,

the motor cover has a through hole penetrating 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.

10. The electric pump of claim 8,

the bus bar unit is cylindrical and extends along the axial direction,

the bearing holding portion is located radially inward of the busbar unit.