CN215058124U

CN215058124U - Electric oil pump

Info

Publication number: CN215058124U
Application number: CN202120445252.0U
Authority: CN
Inventors: 桥本裕; 樋口孔二; 小林喜幸; 永井友三
Original assignee: Nidec Tosok Corp
Current assignee: Nidec Powertrain Systems Corp
Priority date: 2020-03-09
Filing date: 2021-03-02
Publication date: 2021-12-07
Anticipated expiration: 2031-03-02
Also published as: JP7363598B2; JP2021139357A

Abstract

The utility model provides an easily process electric oil pump of the perforating hole of connecting oil blanket room and pump chamber. The utility model discloses an embodiment of electric oil pump includes: a motor unit having a shaft extending in an axial direction of the central shaft; a pump section; an inverter section; and a housing. The housing includes: an oil seal contacting an outer circumferential surface of the shaft; a pump chamber for accommodating the pump section; an oil seal chamber disposed between the pump chamber and the stator in the axial direction and accommodating an oil seal; and a through hole communicating the pump chamber and the oil seal chamber. The pump chamber includes: an inner circumferential wall facing radially inward; a bottom wall connected to an end portion of one side of the inner circumferential wall in the axial direction and facing the other side in the axial direction; a groove recessed from the bottom wall toward one side in the axial direction, the groove facing a radial gap between the inner rotor and the outer rotor from one side in the axial direction; a groove inner wall located at a radially inner end portion of the groove and facing a radially outer side; and a recess portion recessed radially inward from the groove inner wall. At least a part of the through hole is opened in the recess.

Description

Electric oil pump

Technical Field

The utility model relates to an electric oil pump.

Background

In a conventional electric oil pump, an oil seal is provided between a motor section and a pump section, thereby preventing oil from entering from the pump section to the motor section. The fluid pump of patent document 1 includes a pump housing and a motor housing. The pump housing has a through hole that communicates the space in which the oil seal is disposed with the pump chamber. The oil flows in the through-holes.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent No. 5622033 publication

SUMMERY OF THE UTILITY MODEL

[ problem to be solved by the utility model ]

For example, as the diameter of the oil seal is required to be reduced or the electric oil pump is required to be downsized in the axial direction, it is sometimes difficult to drill a through hole connecting a space (oil seal chamber) where the oil seal is disposed and the pump chamber by a machining device such as a drill.

In view of the above, an object of the present invention is to provide an electric oil pump in which a through hole for connecting an oil seal chamber and a pump chamber can be easily formed.

[ means for solving problems ]

The utility model discloses an electric oil pump's first form includes: a motor unit having a shaft extending in an axial direction of the central shaft; a pump section connected to the shaft; an inverter unit that controls rotation of the motor unit; and a case that houses the motor section, the pump section, and the inverter section. The motor portion has a stator. The pump portion has an inner rotor, and an outer rotor surrounding the inner rotor from a radially outer side. The housing has: an oil seal in a ring shape having the center axis as a center, the oil seal being in contact with an outer peripheral surface of the shaft; a pump chamber that accommodates the pump section; an oil seal chamber disposed between the pump chamber and the stator in an axial direction and accommodating the oil seal; and a through hole communicating the pump chamber and the oil seal chamber. The pump chamber has: an inner circumferential wall facing radially inward; a bottom wall connected to an end portion of one side of the inner circumferential wall in the axial direction and facing the other side in the axial direction; a groove recessed from the bottom wall toward one side in the axial direction, the groove facing a radial gap between the inner rotor and the outer rotor from one side in the axial direction; a groove inner wall located at a radially inner end portion of the groove toward a radially outer side; and a recess portion recessed radially inward from the groove inner wall. At least a part of the through hole is opened in the recess.

The second aspect of the electric oil pump of the present invention is the electric oil pump according to the first aspect, wherein the concave portion has an inclined surface located radially outward along with facing one side of the axial direction, and the through hole has a portion opened on the inclined surface.

The utility model discloses an electric oil pump's third form is according to the electric oil pump of first form or second form, wherein the casing includes: a suction port that sucks oil into the pump chamber; and a discharge port that discharges oil from the pump chamber; the portion of the through hole that opens into the recess overlaps the suction port when viewed in the axial direction.

The utility model discloses an electric oil pump's fourth form is according to the electric oil pump of first form, wherein the groove is the suction groove of oil of inhaling.

The utility model discloses an electric oil pump's fifth form is according to the electric oil pump of first form, wherein the groove extends on the circumferencial direction, the groove includes: a first groove part, the depth of the groove in the axial direction is fixed in the circumferential direction; and a second groove portion that is connected to the first groove portion in a circumferential direction, and that has a shallower groove depth in an axial direction with distance from the first groove portion in the circumferential direction; the recess is disposed in a portion of the groove inner wall located in the first groove portion.

The sixth aspect of the electric oil pump of the present invention is the electric oil pump according to the first aspect, wherein the concave portion is a groove-like portion extending in the axial direction the bottom wall is open.

The seventh aspect of the electric oil pump of the present invention is the electric oil pump according to the first aspect, wherein the surface of the concave portion is a casting surface.

An eighth aspect of the electric oil pump according to the first aspect is the electric oil pump according to the eighth aspect, wherein the imaginary line obtained by extending the through hole does not intersect with the inner circumferential wall.

[ effects of the utility model ]

According to an aspect of the present invention, there is provided an electric oil pump in which a through hole for connecting an oil seal chamber and a pump chamber is easily formed.

Drawings

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

Fig. 2 is an enlarged cross-sectional view showing a part of the housing main body, and is a view for explaining the drilling of the through hole by a processing device such as a drill.

Fig. 3 is an enlarged bottom view of a part of the housing main body.

Fig. 4 is an enlarged perspective view of a part of the housing main body.

[ description of symbols ]

10: electric oil pump

20: motor unit

22: shaft

26: stator

30: pump section

30 a: inner rotor

30 b: external rotor

40: shell body

41 g: oil seal

41 i: oil seal chamber

44 a: suction inlet

44 b: discharge port

46: pump chamber

46 a: inner peripheral wall

46 b: bottom wall

46 c: trough (suction trough)

46 e: inner wall of the tank

46 f: concave part

46 g: a first groove part

46 h: the second groove part

46k is as follows: inclined plane

47: through hole

50: inverter unit

J: center shaft

VL: imaginary line

Detailed Description

An electric oil pump 10 according to an embodiment of the present invention will be described with reference to the drawings. The electric oil pump 10 is mounted on a drive device of a vehicle, not shown, for example. That is, the electric oil pump 10 is mounted on the vehicle. As shown in fig. 1, the electric oil pump 10 includes: the motor unit 20, the pump unit 30, the inverter unit 50, the housing 40, and a connector unit not shown.

The motor unit 20 has a shaft 22 having a center axis J as a center, and the center axis J extends in the Z-axis direction. In the following description, a direction parallel to the central axis J will be simply referred to as an "axial direction". The axial direction is a direction in which the central axis J extends. In the present embodiment, the axial position of the motor unit 20 and the axial position of the inverter unit 50 are different from each other. That is, the motor unit 20 and the inverter unit 50 are arranged at different positions in the axial direction. Of the axial directions, a direction from the motor unit 20 to the inverter unit 50 is referred to as an axial direction side (+ Z side), and a direction from the inverter unit 50 to the motor unit 20 is referred to as an axial direction other side (-Z side).

The radial direction centered on the central axis J is simply referred to as "radial direction". Of the radial directions, a direction approaching the central axis J is referred to as a radially inner side, and a direction away from the central axis J is referred to as a radially outer side. The circumferential direction around the central axis J, i.e., the axis around the central axis J, is simply referred to as the "circumferential direction". In the present embodiment, the "parallel direction" includes a substantially parallel direction, and the "orthogonal direction" includes a substantially orthogonal direction.

The motor unit 20 includes: a rotor 21, a stator 26, and a plurality of

bearings

11, 12. The rotor 21 has: shaft 22, rotor core 23, and magnet 24.

The shaft 22 extends in the axial direction. The shaft 22 rotates about the central axis J. The shaft 22 is supported by a plurality of

bearings

11 and 12 to be rotatable around the central axis J. In other words, the plurality of

bearings

11 and 12 rotatably support the shaft 22. The plurality of

bearings

11 and 12 are, for example, ball bearings. Of the plurality of

bearings

11, 12, the first bearing 11 supports a portion of the shaft 22 located on the other side in the axial direction than the rotor core 23. Of the plurality of

bearings

11 and 12, the second bearing 12 supports a portion of the shaft 22 located on the axial direction side of the rotor core 23.

The rotor core 23 is fixed to the outer peripheral surface of the shaft 22. The rotor core 23 is annular with the center axis J as the center. The rotor core 23 is cylindrical and extends in the axial direction. The rotor core 23 is formed by, for example, laminating a plurality of electromagnetic steel plates in the axial direction.

The magnet 24 is disposed at the radially outer end of the rotor core 23. The magnet 24 is provided in plurality. The plurality of magnets 24 are arranged at radially outer ends of the rotor core 23 at intervals in the circumferential direction. The magnet 24 may be, for example, a cylindrical ring magnet.

The stator 26 is disposed radially outward of the rotor 21, and faces the rotor 21 with a gap therebetween in the radial direction. That is, the stator 26 is radially opposed to the rotor 21. The stator 26 surrounds the rotor 21 from the radially outer side over the entire circumference in the circumferential direction. The stator 26 has: a stator core 27, an insulator 28, and a plurality of coils 29.

The stator core 27 has a ring shape with the center axis J as the center. The stator core 27 is disposed radially outward of the rotor 21, and faces the rotor 21 with a gap therebetween in the radial direction. The stator core 27 is formed by laminating a plurality of electromagnetic steel plates in the axial direction, for example.

The stator core 27 has a core back and a plurality of teeth. The core back is annular with the central axis J as the center. The core back is cylindrical extending in the axial direction. The radially outer side surface of the core back is fixed to an inner peripheral surface of a housing main body 41, which will be described later, of the housing 40. The core back is fitted in the housing body 41. The teeth protrude from a radially inner side surface of the core back toward a radially inner side. The teeth are plate-shaped, and the pair of plate surfaces face in the circumferential direction. The plurality of teeth are arranged on the radial inner side surface of the core back at intervals in the circumferential direction.

An insulator 28 is mounted to the stator core 27. The insulator 28 has a portion that covers the teeth. The insulator 28 comprises an insulating material. The insulator 28 is made of, for example, resin.

The plurality of coils 29 are attached to the stator core 27 via the insulator 28. That is, the plurality of coils 29 are mounted on the stator core 27. The plurality of coils 29 are each configured by winding a wire around each tooth via an insulator 28. The coil 29 is electrically connected to an inverter board 55 described later.

The pump section 30 is driven by the motor section 20. The pump section 30 is disposed on the other axial side than the stator 26. The pump section 30 is connected to the other end of the shaft 22 in the axial direction. In other words, the pump section 30 is coupled to the shaft 22. In the present embodiment, the pump section 30 has a trochoid pump structure. The pump section 30 includes an inner rotor 30a and an outer rotor 30b located radially outward of the inner rotor 30 a. The inner rotor 30a and the outer rotor 30b are pump gears, and are engaged with each other. The inner rotor 30a and the outer rotor 30b have trochoid tooth profiles, respectively. The inner rotor 30a is fixed to the other end of the shaft 22 in the axial direction. The outer rotor 30b surrounds the inner rotor 30a from the radially outer side. The motor section 20 rotates the inner rotor 30a to drive the pump section 30.

The inverter 50 is electrically connected to the motor 20. The inverter unit 50 controls the rotation of the motor unit 20. The inverter unit 50 includes an inverter substrate 55 and a capacitor, not shown. The inverter board 55 has a plate shape with a pair of plates facing in the axial direction. The inverter board 55 is positioned on one axial side of the stator 26. The inverter board 55 is supported from the other side in the axial direction by a plurality of post portions 41f of a housing main body portion 41 of the housing 40, which will be described later, and is fixed to each post portion 41f by a screw 73. Although not particularly shown, the capacitor is an electronic component mounted on the other surface of the inverter substrate 55 in the axial direction. The capacitor protrudes from the inverter substrate 55 toward the other side in the axial direction.

The case 40 houses the motor unit 20, the pump unit 30, and the inverter unit 50. The housing 40 has: a housing body portion 41, a pump cover 44, a bearing retainer 42, and an inverter cover 43.

The housing body 41 is made of metal. The housing body 41 accommodates at least the motor 20. In the present embodiment, the housing main body 41 houses the motor unit 20 and the pump unit 30. The housing body 41 is cylindrical and extends in the axial direction. The case body 41 has a bottomed cylindrical shape.

The housing body portion 41 has: the peripheral wall portion 41a, the first flange portion 41j, the column portion 41f, the bottom wall portion 41b, the bearing retainer cylinder portion 41h, the oil seal 41g, the pump chamber 46, the oil seal chamber 41i, and the through hole 47.

That is, the housing 40 has: an oil seal 41g, a pump chamber 46, an oil seal chamber 41i, and a through hole 47.

The peripheral wall portion 41a is cylindrical with the center axis J as the center, and extends in the axial direction. The stator core 27 is fitted inside the peripheral wall portion 41 a. The first flange portion 41j extends radially outward from one axial end of the peripheral wall portion 41 a. The column portion 41f is disposed at one axial end of the peripheral wall portion 41a and extends in the axial direction. The column portion 41f is disposed in an opening portion on one side of the peripheral wall portion 41a in the axial direction. The plurality of column portions 41f are provided at intervals in the circumferential direction. The plurality of pillar portions 41f overlap the inverter board 55 when viewed from the axial direction. An end surface of each pillar portion 41f facing one side in the axial direction is in contact with a plate surface of the inverter board 55 facing the other side in the axial direction.

As shown in fig. 2, the bottom wall portion 41b is connected to the other end portion of the peripheral wall portion 41a in the axial direction. The bottom wall portion 41b has: a first annular plate 41c, a cylindrical wall 41d, and a second annular plate 41 e. The first annular plate portion 41c has an annular plate shape with the center axis J as the center, and the pair of plates face in the axial direction. The outer peripheral portion of the first annular plate portion 41c is connected to the other end portion of the peripheral wall portion 41a in the axial direction. The cylindrical wall portion 41d is disposed radially inward of the peripheral wall portion 41 a. The cylindrical wall portion 41d is cylindrical with the center axis J as the center, and extends in the axial direction. The other end of the cylindrical wall 41d in the axial direction is connected to the inner peripheral portion of the first annular plate 41 c. The second annular plate portion 41e has an annular plate shape with the center axis J as the center, and the pair of plates face in the axial direction. The second annular plate portion 41e is positioned on the axial direction side of the first annular plate portion 41 c. The outer peripheral portion of the second annular plate portion 41e is connected to one end portion of the cylindrical wall portion 41d in the axial direction.

The bearing retainer cylinder portion 41h is cylindrical with the center axis J as the center, and extends in the axial direction. The bearing retainer cylindrical portion 41h protrudes from the plate surface of the second annular plate portion 41e on the one side in the axial direction toward the one side in the axial direction. As shown in fig. 1, the bearing retainer cylinder portion 41h retains the first bearing 11. The first bearing 11 is fitted in the bearing retainer cylinder portion 41 h. The first bearing 11 is disposed in one axial side portion of the bearing retainer cylinder portion 41 h.

The oil seal 41g is annular with the center axis J as the center. The oil seal 41g is disposed in the bearing retainer cylinder portion 41h and is positioned on the other side in the axial direction than the first bearing 11. The oil seal 41g is disposed in the other axial side portion of the bearing retainer cylinder portion 41 h. The outer peripheral portion of the oil seal 41g is in contact with the inner peripheral surface of the bearing retainer cylinder portion 41h over the entire periphery. The inner peripheral portion of the oil seal 41g is in contact with the outer peripheral surface of the shaft 22 over the entire circumference. That is, the oil seal 41g is in contact with the outer peripheral surface of the shaft 22.

The pump chamber 46 is disposed at the other axial end of the housing body 41. The pump chamber 46 is a bottomed hole recessed from the end surface of the housing body portion 41 on the other side in the axial direction toward the one side in the axial direction. In the present embodiment, the pump chamber 46 has a circular hole shape with the center axis J as the center. The pump section 30 is disposed in the pump chamber 46. The pump chamber 46 houses the pump section 30. The pump chamber 46 has a structure other than the above-described structure, which will be described later.

The oil seal chamber 41i includes a portion on the other axial side of the inner peripheral surface of the bearing retainer cylinder portion 41h, and an inner peripheral portion of the plate surface on one axial side of the second annular plate portion 41 e. The oil seal chamber 41i is a cylindrical chamber having the center axis J as the center. The oil seal chamber 41i is disposed on the other axial side than the stator 26. The oil seal chamber 41i is disposed on the axial direction side of the pump chamber 46. That is, the oil seal chamber 41i is disposed between the pump chamber 46 and the stator 26 in the axial direction. The oil seal chamber 41i accommodates an oil seal 41 g.

As shown in fig. 2, the pump chamber 46 includes: the inner peripheral surface of the cylindrical wall portion 41d and the plate surface of the second annular plate portion 41e on the other side in the axial direction. The opening on the other axial side of the pump chamber 46 is closed by a pump cover 44. As shown in fig. 2 to 4, the pump chamber 46 includes: inner peripheral wall 46a, bottom wall 46b, groove 46c, groove 46d, groove inner wall 46e, and recess 46 f.

The inner peripheral wall 46a includes an inner peripheral surface of the cylindrical wall portion 41 d. The inner circumferential wall 46a faces radially inward. As shown in fig. 1, the inner circumferential wall 46a contacts the outer circumferential surface of the outer rotor 30 b. The inner peripheral wall 46a is fixed to the outer peripheral surface of the outer rotor 30 b. The bottom wall 46b includes the plate surface of the second annular plate portion 41e facing the other side in the axial direction. The bottom wall 46b is connected to one end of the inner peripheral wall 46a in the axial direction and faces the other end in the axial direction.

As shown in fig. 2 to 4, one groove 46c of the pair of

grooves

46c, 46d is recessed from the bottom wall 46b toward one side in the axial direction. The groove 46c is located at one axial end of the pump chamber 46, and constitutes a part of the pump chamber 46. The groove 46c is disposed on the other axial side than the oil seal chamber 41 i. The groove 46c is disposed radially outward of the oil seal chamber 41 i. The groove 46c extends in an arc shape along the circumferential direction. That is, the groove 46c extends in the circumferential direction. As shown in fig. 3, the circumferential length of the groove 46c is less than 180 ° in terms of a center angle with the center axis J as the center. As shown in fig. 1, the groove 46c faces the gap in the radial direction between the inner rotor 30a and the outer rotor 30b from the axial direction side. The groove 46c is a suction groove for sucking oil. The inner rotor 30a and the outer rotor 30b rotate relatively to each other, and the pump portion 30 is driven, whereby negative pressure acts on the groove 46 c.

As shown in fig. 3 and 4, the groove 46c includes a first groove portion 46g and a second groove portion 46 h. The first groove portion 46g and the second groove portion 46h are connected to each other in the circumferential direction. In the following description, a direction from the first groove portion 46g to the second groove portion 46h in the groove 46c in the circumferential direction is referred to as a circumferential one side θ 1, and a direction from the second groove portion 46h to the first groove portion 46g in the groove 46c is referred to as a circumferential other side θ 2. The first groove portion 46g is disposed in the portion on the other circumferential direction side θ 2 among the grooves 46 c. The second groove portion 46h is disposed in a portion on one side θ 1 in the circumferential direction among the grooves 46 c. The groove 46c has a larger radial length, i.e., a larger groove width, as it goes toward the circumferential side θ 1.

The depth of the first groove portion 46g recessed from the bottom wall 46b toward one side in the axial direction is constant along the circumferential direction. That is, the first groove portion 46g has a constant groove depth in the axial direction in the circumferential direction. The first groove portion 46g has a larger radial length, i.e., a larger groove width, toward the circumferential direction side θ 1. The second groove portion 46h is connected to the first groove portion 46g in the circumferential direction, and the groove depth in the axial direction becomes shallower as it becomes farther from the first groove portion 46g in the circumferential direction. That is, the groove depth of the second groove portion 46h in the axial direction becomes smaller toward the circumferential direction side θ 1. The groove depth of the end portion on the other circumferential side θ 2 of the second groove portion 46h is the same as the groove depth of the first groove portion 46 g. The second groove portion 46h has a larger groove width toward the circumferential direction side θ 1.

As shown in fig. 2 to 4, the other groove 46d of the pair of

grooves

46c, 46d is recessed from the bottom wall 46b toward one side in the axial direction. The groove 46d is located at one axial end of the pump chamber 46, and constitutes a part of the pump chamber 46. The groove 46d is disposed on the other axial side than the oil seal chamber 41 i. The groove 46d is disposed radially outward of the oil seal chamber 41 i. The groove 46d extends in an arc shape along the circumferential direction. That is, the groove 46d extends in the circumferential direction. The other groove 46d is arranged at a position different from the one groove 46c in the circumferential direction. As shown in fig. 3, the circumferential length of the groove 46d is less than 180 ° in terms of a center angle with the center axis J as the center. As shown in fig. 1, the groove 46d faces the gap in the radial direction between the inner rotor 30a and the outer rotor 30b from the axial direction side. The groove 46d is a discharge groove for discharging oil. The inner rotor 30a and the outer rotor 30b rotate relative to each other, and the pump portion 30 is driven, whereby positive pressure acts on the groove 46 d.

As shown in fig. 3 and 4, the groove 46d includes a third groove portion 46i and a fourth groove portion 46 j. The third groove portion 46i and the fourth groove portion 46j are connected to each other in the circumferential direction. In the circumferential direction, a direction from the third groove portion 46i to the fourth groove portion 46j in the groove 46d is the other circumferential direction side θ 2, and a direction from the fourth groove portion 46j to the third groove portion 46i in the groove 46d is the one circumferential direction side θ 1. The third groove portion 46i is disposed at a portion on one side θ 1 in the circumferential direction among the grooves 46 d. The fourth groove portion 46j is disposed in the portion on the other circumferential direction θ 2 among the grooves 46 d. The groove 46d has a larger radial length, i.e., a larger groove width, as it goes toward the other circumferential side θ 2.

The depth of the third groove portion 46i recessed from the bottom wall 46b toward one side in the axial direction is constant along the circumferential direction. That is, the groove depth of the third groove portion 46i in the axial direction is constant in the circumferential direction. The third groove portion 46i has a larger radial length, i.e., a larger groove width, toward the other circumferential side θ 2. The fourth groove portion 46j and the third groove portion 46i are connected in the circumferential direction, and the groove depth in the axial direction becomes shallower as the distance from the third groove portion 46i in the circumferential direction increases. That is, the groove depth of the fourth groove portion 46j in the axial direction decreases toward the other circumferential direction side θ 2. The groove depth of the end portion on the circumferential direction side θ 1 of the fourth groove portion 46j is the same as the groove depth of the third groove portion 46 i. The fourth groove portion 46j has a larger groove width toward the other circumferential side θ 2.

As shown in fig. 2 to 4, the groove inner wall 46e includes a circumferential wall located radially inward of a pair of circumferential walls (side walls) of one groove 46c in the groove width direction, i.e., the radial direction. That is, the groove inner wall 46e is located at the radially inner end of the groove 46c, facing radially outward. The groove inner wall 46e is located on the other side in the axial direction than the oil seal chamber 41 i. The groove inner wall 46e is located radially outward of the oil seal chamber 41 i.

The recess 46f is recessed radially inward from the groove inner wall 46 e. The recess 46f is disposed at least in part of the groove inner wall 46e in the axial direction. In the present embodiment, the recessed portion 46f is disposed in the groove inner wall 46e over the entire length of the groove inner wall 46e in the axial direction. The recess 46f is groove-shaped and extends in the axial direction, and opens at the bottom wall 46 b. The recess 46f is located on the other axial side than the oil seal chamber 41 i. The recess 46f is located radially outward of the oil seal chamber 41 i. The configuration of the concave portion 46f other than the above will be described later.

As shown in fig. 1, the through hole 47 communicates the pump chamber 46 with the oil seal chamber 41 i. The through hole 47 has a function of flowing the oil accumulated in the oil seal chamber 41i to the pump chamber 46. The through hole 47 is circular and is located radially outward toward the other axial side. That is, the through hole 47 extends obliquely to the central axis J. As shown in fig. 2 to 4, at least a part of the through hole 47 opens in the recess 46 f. The other end of the through hole 47 in the axial direction opens into the recess 46 f. The radially outer end of the through hole 47 opens into the recess 46 f. One end of the through hole 47 in the axial direction opens into the oil seal chamber 41 i. The radially inner end portion of the through hole 47 opens in the oil seal chamber 41 i.

According to the present embodiment, as shown in fig. 2, when the through hole 47 is drilled in the housing 40 by a machining device such as a drill (hereinafter, sometimes referred to as a drill D), the cutting edge of the drill D is brought into contact with the recessed portion 46f, whereby the cutting edge is less likely to be displaced. This enables the through hole 47 to be easily and stably processed at a predetermined position. Therefore, the productivity of the electric oil pump 10 can be improved.

In the present embodiment, since the through hole 47 opens in the recessed portion 46f of the groove inner wall 46e of the groove 46c as the suction groove, the oil accumulated in the oil seal chamber 41i is stably sucked into the pump chamber 46 through the through hole 47.

In the present embodiment, the recess 46f is formed in a groove shape extending in the axial direction and opens at the bottom wall 46b, so that the cutting edge of the drill D can easily enter the recess 46f without interference. Further, since the recess 46f opens to the bottom wall 46b toward the other axial side, the recess 46f can be easily molded when the case 40 is cast.

The surface of the recess 46f is a casting surface. That is, in the present embodiment, the recess 46f is formed when the housing 40 is cast. Therefore, the recess 46f can be provided without increasing the number of manufacturing steps, and the through hole 47 can be stably processed.

As shown in fig. 2 and 4, the recess 46f has an inclined surface 46 k. The inclined surface 46k is disposed at one axial end of the recess 46 f. The inclined surface 46k is located radially outward as it faces one side in the axial direction. The inclined surface 46k faces radially outward and axially the other side. In the present embodiment, the inclined surface 46k has a concave curved surface. The through hole 47 has a portion opened at the inclined surface 46 k. The other end of the through hole 47 in the axial direction opens at the inclined surface 46 k. The radially outer end of the through hole 47 opens at the inclined surface 46 k. In the present embodiment, the through hole 47 can be drilled with the tip of the drill D facing the inclined surface 46 k. Therefore, the cutting edge of the drill D is less likely to be displaced, and the through hole 47 can be accurately processed at a predetermined position.

As shown in fig. 3 and 4, the concave portion 46f is disposed in a portion of the groove inner wall 46e located at the first groove portion 46 g. Specifically, the recess 46f is open at a portion of the groove inner wall 46e located at the end of the first groove portion 46g on the one circumferential side θ 1. In the present embodiment, the recess 46f is provided in the portion of the first groove portion 46g located on the groove inner wall 46e where the groove depth in the axial direction is constant, and therefore, the recess 46f can be easily and stably manufactured.

As shown in fig. 2, the inner peripheral wall 46a is not located on an extension line extending the through hole 47 toward the pump chamber 46. Specifically, the virtual line VL extending from the through hole 47 to the radially outer side and the other axial side is disposed on the other axial side than the inner circumferential wall 46a at the same radial position as the inner circumferential wall 46 a. That is, the virtual line VL extending the through hole 47 does not intersect the inner circumferential wall 46 a. According to the present embodiment, since the drill D is suppressed from interfering with the bottom wall portion 41b including the inner peripheral wall 46a, the through hole 47 can be easily processed by the drill D, thereby improving productivity.

As shown in fig. 1, the pump cover 44 is disposed on the other axial side of the housing main body portion 41. The pump cover 44 is in contact with the end surface of the casing body portion 41 on the other side in the axial direction. The pump cover 44 is fixed to the other end portion in the axial direction of the housing main body portion 41 by a bolt member not shown. The pump cover 44 covers the pump section 30 from the other side in the axial direction. The pump cover 44 has a suction port 44a and a discharge port 44 b. That is, the casing 40 has a suction port 44a and a discharge port 44 b.

The suction port 44a opens on the other surface of the pump cover 44 in the axial direction. The suction port 44a penetrates the pump cover 44 in the axial direction. The suction port 44a communicates with the pump chamber 46. The suction port 44a sucks the oil into the pump chamber 46. The suction port 44a overlaps a part of the groove 46c when viewed from the axial direction. The suction port 44a and the concave portion 46f overlap each other when viewed from the axial direction. Therefore, the portion of the through hole 47 that opens into the recess 46f overlaps the suction port 44a when viewed in the axial direction. In the present embodiment, the through hole 47 is opened at a position overlapping with the suction port 44a in the pump chamber 46 when viewed from the axial direction, and therefore the negative pressure of the pump chamber 46 is easily applied to the through hole 47. Therefore, the oil accumulated in the oil seal chamber 41i is stably sucked into and discharged from the pump chamber 46 through the through hole 47.

The discharge port 44b opens on the other surface of the pump cover 44 in the axial direction. The discharge port 44b penetrates the pump cover 44 in the axial direction. The discharge port 44b communicates with the pump chamber 46. The discharge port 44b discharges oil from the pump chamber 46. The discharge port 44b overlaps with a part of the groove 46d when viewed from the axial direction.

The bearing holder 42 is disposed inside the housing body 41. The bearing holder 42 is disposed on one side of the rotor core 23 in the axial direction. The bearing retainer 42 retains the second bearing 12. The bearing holder 42 is fixed to an end portion of the housing body 41 on one side in the axial direction.

The inverter cover 43 is disposed on one side in the axial direction of the case main body 41. The inverter cover 43 covers the inverter portion 50 from one axial side. The inverter cover 43 has a cover portion 43a and a second flange portion 43 b. The cover portion 43a faces the inverter board 55 from one side in the axial direction. The second flange portion 43b is radially outwardly expanded from the other axial end of the cover portion 43 a. The second flange portion 43b contacts the first flange portion 41j of the housing body portion 41 from the axial direction side. The first flange portion 41j and the second flange portion 43b are fixed to each other by a bolt member 48.

Although not particularly shown, the connector portion is attached to the housing body portion 41. The connector portion has a portion inserted into a hole portion penetrating the peripheral wall portion 41a in the radial direction and a portion protruding outward in the radial direction from the hole portion. The connector portion further includes a resin portion and a wiring member embedded in the resin portion. The wiring member is connected to the inverter board 55. An external power supply, not shown, for supplying electric power to the stator 26 is connected to the connector portion.

The present invention is not limited to the above-described embodiments, and for example, as described below, structural changes and the like may be made without departing from the scope of the present invention.

In the above embodiment, the recess 46f is in the form of a groove extending in the axial direction, but the present invention is not limited thereto. For example, the recess 46f may have a hole shape recessed radially inward from the groove inner wall 46 e.

Further, the respective configurations (constituent elements) described in the above-described embodiments, modifications, and descriptions may be combined, and addition, omission, replacement, and other changes of the configurations may be made without departing from the scope of the present invention. In addition, the present invention is not limited by the embodiments, but only by the claims.

Claims

1. An electric oil pump, characterized by comprising:

a motor unit having a shaft extending in an axial direction of the central shaft;

a pump section connected to the shaft;

an inverter unit that controls rotation of the motor unit; and

a case that houses the motor unit, the pump unit, and the inverter unit;

the motor part is provided with a stator,

the pump section includes: an inner rotor, and an outer rotor surrounding the inner rotor from a radially outer side,

the housing includes:

an oil seal in a ring shape having the center axis as a center, the oil seal being in contact with an outer peripheral surface of the shaft;

a pump chamber that accommodates the pump section;

an oil seal chamber disposed between the pump chamber and the stator in an axial direction and accommodating the oil seal; and

a through hole communicating the pump chamber and the oil seal chamber;

the pump chamber includes:

an inner circumferential wall facing radially inward;

a bottom wall connected to an end portion of one side of the inner circumferential wall in the axial direction and facing the other side in the axial direction;

a groove recessed from the bottom wall toward one side in the axial direction, the groove facing a radial gap between the inner rotor and the outer rotor from one side in the axial direction;

a groove inner wall located at a radially inner end portion of the groove toward a radially outer side; and

a recess recessed radially inward from the groove inner wall;

at least a part of the through hole is opened in the recess.

2. The electric oil pump according to claim 1,

the recess has an inclined surface located radially outward with facing one side in the axial direction,

the through hole has a portion opened to the inclined surface.

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

the housing includes:

a suction port that sucks oil into the pump chamber; and

a discharge port for discharging oil from the pump chamber;

the portion of the through hole that opens into the recess overlaps the suction port when viewed in the axial direction.

4. The electric oil pump according to claim 1,

the groove is a suction groove for sucking oil.

5. The electric oil pump according to claim 1,

the grooves extend in the circumferential direction and,

the tank includes:

a first groove part, the depth of the groove in the axial direction is fixed in the circumferential direction; and

a second groove portion that is connected to the first groove portion in a circumferential direction and has a shallower groove depth in an axial direction with distance from the first groove portion in the circumferential direction;

the recess is disposed in a portion of the groove inner wall located in the first groove portion.

6. The electric oil pump according to claim 1,

the recess is groove-shaped extending in the axial direction and opens at the bottom wall.

7. The electric oil pump according to claim 1,

the surface of the recess is a casting surface.

8. The electric oil pump according to claim 1,

an imaginary line obtained by extending the through hole does not intersect the inner peripheral wall.