CN113424413A

CN113424413A - Motor

Info

Publication number: CN113424413A
Application number: CN202080014512.7A
Authority: CN
Inventors: 石田尚; 梅田智之; 斋藤裕也; 藤原英雄
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2019-03-28
Filing date: 2020-02-20
Publication date: 2021-09-21
Also published as: WO2020195396A1

Abstract

One aspect of the motor of the present invention includes: a rotor that rotates about a central axis; a stator radially opposite to the rotor; a housing made of resin and having a stator embedded therein; a bearing that supports the rotor to be rotatable with respect to the stator; and a bearing holder that holds the bearing. The bearing support has: a resin portion made of resin and holding the bearing; and a bus bar connected to a lead wire extending from the coil of the stator. The bus bar is embedded in the resin portion.

Description

Motor

Technical Field

The present invention relates to a motor.

Background

A motor is known which includes a bus bar connected to a coil wire drawn from a coil. Patent document 1 discloses a bus bar unit including a bus bar holder in which a bus bar is embedded. Such a motor has a metal bearing holder different from the bus bar holder, which rotatably supports a shaft by a bearing.

Documents of the prior art

Patent document

Patent document 1 japanese laid-open gazette: japanese patent laid-open publication No. 2017-201882

Disclosure of Invention

Technical problem to be solved by the invention

In the conventional structure, a bus bar holder and a bearing holder need to be assembled on one axial side of a stator, and the manufacturing process of a motor is complicated.

In view of the above circumstances, an object of the present invention is to simplify the assembly process of a motor by a bearing holder having a function of a bus bar holder.

Technical scheme for solving technical problem

One aspect of the motor of the present invention includes: a rotor that rotates about a central axis; a stator radially opposite the rotor; a housing made of resin and in which the stator is embedded; a bearing that supports the rotor to be rotatable relative to the stator; and a bearing holder that holds the bearing. The bearing support has: a resin portion that is made of resin and holds the bearing; and a bus bar electrically connected with the coil of the stator. The bus bar is embedded in the resin portion.

Effects of the invention

According to one aspect of the present invention, the assembly process of the motor can be simplified by the bearing bracket having the function of the bus bar bracket.

Drawings

Fig. 1 is a sectional view of a motor according to an embodiment.

FIG. 2 is a cross-sectional view of a lower bearing support of an embodiment.

Fig. 3 is a cross-sectional view of a lower bearing bracket according to an embodiment after additional processing.

Fig. 4 is a partial sectional view of a lower bearing bracket according to a first modification.

Fig. 5 is a partial sectional view of a lower bearing bracket according to a second modification.

Detailed Description

Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the accompanying drawings.

In the following description, a direction parallel to the central axis J (see fig. 1) is simply referred to as an "axial direction" or a "vertical direction", a radial direction about the central axis J is simply referred to as a "radial direction", and a circumferential direction about the central axis J, that is, a direction around the central axis J is simply referred to as a "circumferential direction". In the present specification, one side in the axial direction of the central axis J is simply referred to as "upper side", and the other side is simply referred to as "lower side". The vertical direction in this specification is a direction for explanation only, and the posture of the motor during use and circulation is not limited.

Fig. 1 is a sectional view of a motor 1 according to an embodiment.

The motor 1 includes a rotor 10, a stator 20 surrounding the rotor 10, an upper bearing 15 and a lower bearing (bearing) 16 rotatably holding the rotor 10 to the stator 20, an upper bearing holder 40 holding the upper bearing 15, a lower bearing holder (bearing holder) 70 holding the lower bearing 16, and a housing 30.

The rotor 10 rotates about a central axis J extending in the vertical direction. The rotor 10 has a shaft 11 extending along a central axis J, a rotor core 12, and a rotor magnet 13.

The shaft 11 is supported by an upper bearing 15 and a lower bearing 16 so as to be rotatable about the center axis J. A rotor core 12 is fixed to an outer peripheral surface of the shaft 11. Further, a rotor magnet 13 is fixed to the outer peripheral surface of the rotor core 12. The plurality of rotor magnets 13 may be embedded in the rotor core 12.

The upper bearing 15 is located at an upper side of the stator 20, and the lower bearing 16 is located at a lower side of the stator 20. The upper bearing 15 supports an upper end portion of the shaft 11, and the lower bearing 16 supports a lower end portion of the shaft 11. The upper bearing 15 and the lower bearing 16 of the present embodiment are ball bearings. However, the upper bearing 15 and the lower bearing 16 may be other types of bearings such as needle bearings.

The upper bearing bracket 40 is located at an upper side of the stator 20. The upper bearing bracket 40 is made of metal. The upper bearing bracket 40 includes a bracket tube 41, an upper plate 42 extending radially inward from an upper end of the bracket tube 41, and a bracket flange 43 extending radially outward from a lower end of the bracket tube 41.

The holder tube portion 41 is cylindrical with the center axis J as the center. The upper bearing 15 is disposed radially inward of the holder cylinder portion 41. The upper plate portion 42 covers the upper side of the outer ring of the upper bearing 15. The upper plate portion 42 is provided with a center hole 42a penetrating in the axial direction. The shaft 11 is inserted into the central hole 42 a. The radially outer edge of the bracket flange 43 is embedded in the housing 30. That is, at least a part of the upper bearing bracket 40 is buried in the housing 30.

The stator 20 surrounds the rotor 10 from the radially outer side. The stator 20 is radially opposed to the rotor 10. The stator 20 includes a stator core 21, an insulator 22, and a coil 29.

The stator core 21 includes an annular core back 21a centered on the central axis J and a plurality of pole teeth 21b extending radially inward from the core back 21 a. The plurality of pole teeth 21b are provided at equal intervals in the circumferential direction around the center axis J.

The coil 29 is attached to the pole tooth portion 21b via the insulator 22. The end of the coil 29 is connected to a bus bar 80 disposed below the stator 20. The bus 80 is connected to a control device not shown. Power is supplied from the control device to the coil 29 through the bus 80.

The housing 30 is made of a resin material. In the present specification, the resin material may be a composite material reinforced with a fiber material such as glass fiber or carbon fiber. That is, the housing 30 may be made of a fiber-reinforced resin material. The housing 30 may be a thermosetting resin or a thermoplastic resin.

The stator 20 and the upper bearing bracket 40 are embedded in the housing 30. Thereby, the housing 30 holds the stator 20 and the upper bearing bracket 40. The housing 30 is insert-molded in a state where the stator 20 and the upper bearing bracket 40 are held in a mold. That is, since the stator 20 and the upper bearing bracket 40 can be embedded in the housing 30 at one time, the assembly process of the motor 1 is simplified.

The housing 30 includes a body portion 31 that holds the stator 20, a plurality of ribs 3 that protrude upward from the upper surface of the body portion 31, a lower cylindrical portion 37 that extends downward from the outer edge of the body portion 31, a holder holding portion 38 that holds the upper bearing holder 40, and a holding wall portion (wall portion) 39 that is located below the body portion 31 and to which the lower bearing holder 70 is fixed.

The stator 20 is embedded in the body 31. The body 31 surrounds the stator 20 on the upper side, the lower side, and the radial outer side. The main body portion 31 encloses the pole tooth portion 21b and the coil 29, and is also provided between the pole tooth portion 21b and the coil 29 which are adjacent to each other in the circumferential direction. The inner peripheral surface of the stator core 21 is exposed from the housing 30.

The plurality of ribs 3 protrude upward from the upper surface of the body portion 31. The plurality of ribs 3 extend in the circumferential direction as well as in the radial direction to reinforce the housing 30.

The holder holding portion 38 is located on the upper side of the main body portion 31. The holder holding portion 38 extends radially inward from the inner end of the body portion 31. Further, the holder holding portion 38 is located radially inward of the rib 3. The bracket flange portion 43 of the upper bearing bracket 40 is embedded in the bracket holding portion 38. Thereby, the holder holding portion 38 holds the upper bearing holder 40.

The holding wall portion 39 protrudes downward from the lower surface of the body portion 31. That is, the holding wall portion 39 is located below the stator 20. The holding wall portion 39 is annular with the center axis J as the center.

The holding wall portion 39 has a lower surface 39b facing downward and a radially inward attachment inner circumferential surface 39 a. The lower surface 39b is a plane orthogonal to the central axis J. The attachment inner peripheral surface 39a is a cylindrical surface centered on the central axis J. As described later, a lower bearing holder 70 is attached to the lower surface 39b and the attachment inner peripheral surface 39 a.

The holding wall portion 39 has a plurality of mounting pins 39p protruding downward from the lower surface 39 b. The mounting pin 39p is cylindrical in shape extending in the axial direction. The plurality of mounting pins 39p are arranged in the circumferential direction. As described later, the plurality of mounting pins 39p are inserted and heat-staked into the through-holes 73h of the lower bearing bracket 70. Thereby, the holding wall portion 39 holds the lower bearing holder 70.

The lower cylindrical portion 37 is located below the main body portion 31. The lower tube portion 37 is cylindrical with the center axis J as the center. The outer peripheral surface of the lower tube portion 37 is continuous with the outer peripheral surface of the body portion 31. A control device (not shown) for controlling the motor 1 is attached to the lower cylinder portion 37. The bus bar 80 described later is connected to a socket (not shown) provided in the control device. The inner peripheral surface of the lower tube portion 37 and the control device are sealed by a seal structure not shown.

The lower bearing bracket 70 supports the rotor 10 by the lower bearing 16 so as to be rotatable with respect to the stator 20. The lower bearing bracket 70 is located at the lower side of the stator 20. The lower bearing bracket 70 is fixed to the housing 30 below the body portion 31 and radially inward of the lower tube portion 37.

Fig. 2 is a sectional view of the lower bearing bracket 70.

The lower bearing holder 70 includes a resin portion 75 made of resin, and a bus bar 80 embedded in the resin portion 75.

The bus bar 80 is made of a metal material (for example, copper alloy) having high conductivity. The bus bar 80 is plate-shaped. The bus bar 80 is formed by pressing a plate material. The bus bar 80 is connected to the lead-out wire 28 extending from the coil 29. Thereby, the bus bar 80 is electrically connected to the coil 29.

The bus bar 80 includes a base portion 83, an inclined portion 84, a connecting portion 81, and an external connection terminal portion 82.

The base portion 83 extends in a band shape in the radial direction. The base portion 83 has an axial direction as a plate thickness direction. The base portion 83 has an inner end portion 83a as a radially inner end portion and an outer end portion 83b as a radially outer end portion.

The base portion 83 is exposed to the outside at the outer end portion 83b, and is embedded in the resin portion 75 in a region other than the outer end portion 83 b. The base portion 83 has a through hole 83h penetrating in the axial direction. Since base portion 83 is embedded in resin portion 75, a part of resin portion 75 enters through-hole 83h, and bus bar 80 is suppressed from moving inside resin portion 75.

The inclined portion 84 is inclined radially outward and downward from the outer end portion 83b of the base portion 83, and extends in a band shape. The inclined portion 84 is connected to the base portion 83 at an upper end portion and connected to the connection portion 81 at a lower end portion. That is, the slope portion 84 connects the base portion 83 and the connection portion 81.

The connecting portion 81 extends in a band shape in the axial direction. The connecting portion 81 is formed in the plate thickness direction in the radial direction. The connection portion 81 is connected to the inclined portion 84 at an upper end portion. The connecting portion 81 has an outer surface 81b facing radially outward. The connection portion 81 is connected to the lead wire 28 on the outer surface 81 b. The connection means between the connection portion 81 and the lead wire 28 is not particularly limited, and is resistance welding, for example.

The lead wire 28 connected to the connection portion 81 is the end of the coil 29 at which the winding starts or the end of the winding ends. The lead wires 28 extend from the lower surface of the body portion 31 of the housing 30 and are exposed. A plurality of lead wires 28 may be connected to one connection portion 81. Here, a case where the lead wire 28 is directly connected to the bus bar 80 is described. However, the lead wire 28 may be connected to a relay bus embedded in the body 31, and a terminal of the relay bus may be exposed from the body 31 and connected to the connection portion 81. That is, the bus bar 80 may be electrically connected to the coil 29 by another member.

The external connection terminal portion 82 extends in a band shape in the axial direction. The external connection terminal portion 82 is formed in the plate thickness direction in the radial direction. The external connection terminal portion 82 is connected at an upper end portion to an inner end portion 83a of the base portion 83. The external connection terminal portion 82 is embedded in the resin portion 75 at an upper end portion and exposed from the resin portion 75 at a lower end portion. The external connection terminal portion 82 protrudes downward from the lower surface of the resin portion 75.

The external connection terminal portion 82 is inserted into a socket portion provided in a control device, not shown. Thereby, the bus 80 is connected to the control device. The control device supplies power to the stator 20 through the bus 80.

The resin portion 75 holds the lower bearing 16. The resin material constituting the resin portion 75 may be a composite material reinforced with a nonconductive fiber material such as glass fiber. That is, the housing 30 may be made of a fiber-reinforced resin material. The resin material constituting the resin portion 75 may be a thermosetting resin or a thermoplastic resin.

The resin portion 75 includes a tube portion 71, a first bottom plate portion 72 extending radially inward from a lower end of the tube portion 71, a flange portion 73 extending radially outward from an outer peripheral surface of the tube portion 71, and an annular portion 74 protruding upward from the flange portion 73. In the resin portion 75, a part of the bus bar 80 is embedded in the flange portion 73.

The cylindrical portion 71 is cylindrical with the center axis J as the center. The lower bearing 16 is disposed radially inward of the cylindrical portion 71. That is, the cylindrical portion 71 surrounds the lower bearing 16 from the radially outer side. Thereby, the lower bearing 16 is positioned in the radial direction on the lower bearing bracket 70.

The first bottom plate portion 72 extends radially inward from the lower end of the tube portion 71. The first bottom plate portion 72 is in contact with the lower surface of the outer race of the lower bearing 16. Thereby, the lower bearing holder 70 restricts the lower bearing 16 from moving downward. The first bottom plate portion 72 is provided with a center hole 72a penetrating in the radial direction. The shaft 11 is inserted into the central hole 72.

The flange 73 extends radially outward from the tube 71. The flange portion 73 is a disk shape centered on the central axis J and having the plate thickness direction in the axial direction. A part of the bus bar 80 is embedded in the flange portion 73. The external connection terminal portion 82 protrudes downward from the lower surface 73c of the flange portion 73. The base portion 83 protrudes radially outward from the outer edge 73a of the flange portion 73.

The flange 73 is connected to the axial center of the tube 71. That is, the flange 73 extends radially outward from the axial center of the tube 71. Therefore, the flange portion 73 functions as a rib provided on the outer peripheral surface of the tube portion 71 and extending in the circumferential direction, and reinforces the tube portion 71. Thus, even when a load acts on the tube portion 71 from the shaft 11 via the lower bearing 16, deformation of the tube portion 71 can be suppressed. Further, the flange portion 73 is connected to the axial center portion of the tube portion 71, so that the tube portion 71 can be cooled more uniformly during molding. Therefore, according to the present embodiment, the cylindrical portion 71 can be prevented from falling radially inward, as compared with the case where the flange portion is connected to the upper end portion or the lower end portion of the cylindrical portion.

In the present specification, the axial center of the tube 71 refers to a region between the upper end and the lower end of the tube 71, and does not refer to only the axial dimension center of the tube 71.

The annular portion 74 protrudes upward from the upper surface 73b of the flange portion 73, and extends in the circumferential direction around the center axis J. In the present embodiment, the annular portion 74 extends without interruption over the entire circumference in the circumferential direction. However, as long as the annular portion 74 extends annularly in the circumferential direction, a plurality of the annular portions may be arranged discretely in the circumferential direction.

As shown in fig. 1, the flange portion 73 has a plurality of through holes 73h that penetrate in the axial direction. The through holes 73h are arranged in the circumferential direction. The mounting pin 39p of the holding wall portion 39 is inserted into the through hole 73 h. The lower end of the mounting pin 39p is formed into a hemispherical shape larger than the diameter of the through hole 73h by thermal caulking. Thereby, the flange portion 73 is fixed to the housing 30.

In addition, in the case where the lower bearing bracket 70 is fixed to the housing 30 by means of heat caulking, as a resin material constituting the housing 30, a thermoplastic resin is selected.

Upper surface 73b of flange 73 contacts lower surface 39b of retaining wall 39. Thereby, the lower bearing bracket 70 is positioned in the axial direction with respect to the housing 30. The annular portion 74 is fitted inside the holding wall portion 39. More specifically, the outer peripheral surface 74a of the annular portion 74 is in contact with the mounting inner peripheral surface 39a provided on the housing 30 over the entire circumference. Thereby, the lower bearing bracket 70 is positioned in the radial direction with respect to the housing 30.

The annular portion 74 is located inward of the outer edge 73a of the flange portion 73. This effectively reinforces the flange 73 and suppresses deformation of the flange by the annular portion 74. Further, according to the present embodiment, compared to the case where the annular portion is provided on the outer edge of the flange portion, the occurrence of shrinkage cavities in the annular portion 74 can be suppressed during molding, and the dimensional accuracy of the annular portion 74 can be improved. As a result, the positional accuracy of the lower bearing bracket 70 with respect to the housing 30 can be improved.

The annular portion 74 and the cylindrical portion 71 are opposed to each other with a gap therebetween in the radial direction. That is, a gap is provided between the inner peripheral surface of the annular portion 74 and the outer peripheral surface of the tube portion 71. According to the present embodiment, as compared with the case where the cylindrical portion and the annular portion are integrally connected, the local increase in the thickness of the resin portion 75 can be suppressed, and the shrinkage of the resin portion 75 can be suppressed.

In the present embodiment, a case where the resin portion 75 has the annular portion 74 and the tube portion 71, respectively, is described. However, as another structure, the cylindrical portion may function as an annular portion. In the case of such a configuration, the lower bearing is positioned in the housing 30 by fitting the cylindrical portion holding the lower bearing 16 into the inside of the holding wall portion 39.

According to the present embodiment, the resin portion 75 of the lower bearing holder 70 holds not only the lower bearing 16 but also the bus bar 80. Therefore, it is not necessary to provide a bearing bracket and a bus bar bracket separately, and the number of components of the motor 1 can be reduced. As a result, the assembly process of the motor 1 can be simplified, and the motor 1 can be manufactured at low cost.

According to the present embodiment, the lower bearing holder 70 holds the lower bearing 16 and holds the bus bar 80 to function as a bus bar holder. Therefore, the motor 1 can be made smaller than a case where the bearing holder and the bus bar holder are arranged below the stator so that a plurality of members are arranged.

According to the present embodiment, a plurality of bus bars 80 are embedded in the resin portion 75. Therefore, the resin portion 75 is reinforced by the plurality of bus bars 80. Therefore, even when a load is applied from the outside, the deformation of the lower bearing bracket 70 can be suppressed. The load from the shaft 11 is applied to the lower bearing bracket 70 via the lower bearing 16. If the lower bearing bracket 70 is deformed by the load, the rotation axis of the shaft 11 may become unstable, and the power transmission efficiency to the external device may be deteriorated. According to the present embodiment, the resin portion 75 is reinforced by the plurality of bus bars 80, and the rotation of the shaft 11 can be stabilized while suppressing deformation of the lower bearing bracket 70.

Fig. 3 is a view of the lower bearing holder 70 of the present embodiment after further processing. As shown in fig. 3, the lower bearing holder 70 of the present embodiment may be processed to fix the outer ring of the lower bearing 16. According to this structure, the resin portion 75 has the second bottom plate portion 71a extending radially inward from the upper side of the tube portion 71 with respect to the first bottom plate portion 72. For example, the second bottom plate portion 71a is molded by heating and softening the upper end portion of the tube portion 71, pouring the softened upper end portion radially inward, and solidifying the portion poured radially inward again. The second bottom plate portion 71a contacts the upper surface of the outer race of the lower bearing 16. Thereby, the lower bearing holder 70 restricts the upper movement of the lower bearing 16. With this structure, the outer ring of the lower bearing 16 is sandwiched between the first bottom plate 72 and the second bottom plate 71 a. Therefore, the lower bearing 16 can be suppressed from wobbling in the axial direction with respect to the lower bearing bracket 70.

When the second bottom plate portion 71a is molded by heating and softening the resin portion 75, a thermoplastic resin is used as the resin material constituting the resin portion 75.

Next, a modified example of the above embodiment will be described. The same reference numerals are given to the constituent elements of the same embodiment and the description thereof is omitted.

< modification example I >

Fig. 4 is a partial sectional view of a lower bearing holder 170 according to modification 1. The lower bearing bracket 170 of modification 1 will be described below with reference to fig. 4.

The lower bearing bracket 170 of the present modification is mainly different from the above-described embodiment in that a seal member 171c is provided on the inner circumferential surface of the cylindrical portion 171.

The resin portion 75 of the lower bearing bracket 170 has a cylindrical portion 171. The cylindrical portion 171 is cylindrical with the center axis J as the center. The lower bearing 16 is disposed radially inward of the cylindrical portion 171. That is, the cylindrical portion 171 surrounds the lower bearing 16 from the radially outer side.

Two recessed grooves 171b extending in the circumferential direction are provided on the inner circumferential surface of the cylindrical portion 171. Annular seal members 171c are disposed in the two grooves 171b, respectively. That is, the lower bearing bracket 170 has a sealing member 171 c. The sealing member 171c is sandwiched and compressed by the bottom surface of the groove 171b and the outer circumferential surface of the outer ring. In the present modification, the sealing member 171c is an O-ring.

According to the present modification, the compressed seal member 171c is disposed between the inner circumferential surface of the cylinder 171 and the outer circumferential surface of the outer ring. The reaction force of the compressed seal member 171c presses the outer ring of the lower bearing 16 radially inward. As a result, the lower bearing 16 can be prevented from wobbling relative to the lower bearing bracket 170.

< modification example two >

Fig. 5 is a partial sectional view of a lower bearing holder 270 of modification 2. Next, the lower bearing holder 270 of modification 2 will be described with reference to fig. 5.

The lower bearing bracket 270 of the present modification is different from the above embodiment mainly in that it includes a metal bracket portion 276.

The lower bearing holder 270 of the present modification includes: a resin portion 275 made of resin; and the bus bar 80 and the metal bracket portion 276 embedded in the resin portion 275.

The metal bracket 276 is made of metal. The metal bracket portion 276 has: a metal tube portion 279; a metal bottom plate portion 277 extending radially inward from a lower end of the metal tube portion 279; and a brim 278 extending radially outward from an upper end of the metal tube 279.

The resin portion 275 is embedded in the radially outer edge of the eaves portion 278. Thereby, the metal bracket portion 276 is held by the resin portion 275. The eave portion 278 includes: an embedded region 278a embedded in the resin portion 275; and an exposed region 278b exposed from the resin portion 275. Exposed region 278b is located radially inward with respect to buried region 278 a. Embedded region 278a and exposed region 278b are provided on the upper and lower surfaces of eave 278, respectively.

The mold for molding resin portion 275 sandwiches eave portion 278 from above and below in exposed region 278 b. Thereby, the mold supports the metal holder portion 276. According to this modification, by providing the exposed regions 278b on the upper and lower surfaces of the eaves portion 278, the metal bracket 276 can be firmly held in the mold, and the metal bracket 276 can be accurately positioned with respect to the mold. As a result, the positional accuracy of the metal holder portion 276 with respect to the resin portion 275 can be improved.

The metal tube portion 279 has a cylindrical shape centered on the central axis J. The lower bearing 16 is disposed radially inward of the metal tube 279. That is, the metal tube portion 279 surrounds the lower bearing 16 from the radially outer side. Thereby, the lower bearing 16 is positioned in the radial direction on the lower bearing holder 270.

The metal bottom plate portion 277 covers the lower side of the outer race of the lower bearing 16. An elastic member 290 is provided between the metal bottom plate 277 and the outer race of the lower bearing 16. In the present modification, the elastic member 290 is a wave washer. The elastic member 290 applies a preload to the outer race of the lower bearing 16 to suppress the rattling of the lower bearing 16. The metal bottom plate 277 has a center hole 277a that penetrates in the axial direction. A shaft 11 is inserted into the center hole 277 a.

According to the present modification, the metal bracket portion 276 holds the lower bearing 16. That is, the resin portion 275 holds the lower bearing 16 via the metal bracket portion 276 made of metal. Therefore, even when a load is applied to the lower bearing holder 270 from the shaft 11 via the lower bearing 16, deformation of the lower bearing holder 270 can be suppressed, and stability of holding of the shaft 11 can be improved.

The resin portion 275 has: eaves holding portion 272 for embedding embedded region 278a of eaves portion 278; an enclosing cylinder part (cylinder part) 271 extending downward from the outer edge of the eaves holding part 272; a flange portion 273 extending radially outward from the lower end of the surrounding cylinder portion 271; and an annular portion 274 projecting upward from the flange portion 273. Resin portion 275 embeds bus bar 80 at flange portion 273.

The surrounding tubular portion 271 has a tubular shape extending in the axial direction about the central axis J. The surrounding tube 271 surrounds the metal tube 279 with a gap from the radial outside. The surrounding tube 271 is connected to the eave holding portion 272 at an upper end and to the flange 273 at a lower end. Therefore, surrounding tube portion 271 connects eave holding portion 272 and flange portion 273 in a crank shape.

The lower bearing bracket 270 is fixed to the housing 30 at the flange portion 273. In some cases, stress in the radial direction is applied to the flange 273 during fixing to the housing 30. For example, when flange portion 273 is fixed to case 30 by heat staking, thermal stress in the radial direction is applied to flange portion 273. In resin portion 275 of the present modification, flange portion 273, surrounding tube portion 271, and eaves holding portion 272 are bent in a crank shape toward the radially inner side. Therefore, the radial stress applied to the flange portion 273 can be absorbed by the elastic deformation of the crank shape, and the transmission of the radial stress applied to the flange portion 273 to the lower bearing 16 can be suppressed. As a result, the lower bearing 16 can be prevented from being deformed by the stress generated by fixing the flange portion 273 to the housing 30.

The flange portion 273 extends radially outward from the surrounding cylinder portion 271. The flange 273 has a circular plate shape centered on the central axis J and having a plate thickness direction in the axial direction. A part of bus bar 80 is embedded in flange 273. Flange 273 is reinforced by embedding bus bar 80.

The annular portion 274 extends in a rib shape in the circumferential direction around the center axis J. As in the above-described embodiment, the annular portion 274 is fitted into the inside of the holding wall portion 39 (see fig. 1) of the housing 30, and is positioned in the radial direction with respect to the housing 30.

While the embodiment of the present invention and the modified examples thereof have been described above, the configurations and combinations thereof in the embodiment and the modified examples are examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the spirit of the present invention. The present invention is not limited to the embodiments.

For example, the use of the motor of the above embodiment and its modified examples is not particularly limited. The motor according to the above-described embodiment and the modified examples thereof is mounted on, for example, an electric pump, an electric power steering apparatus, and the like.

Description of the symbols

1, a motor; 10 a rotor; 16 lower side bearings (bearings); 20 a stator; 28 lead-out wires; 29 coils; 30 a housing; 39a mounting the inner peripheral surface; 70 lower side bearing support (bearing support); 71. 171 a cylindrical portion; 71a second bottom plate portion; 72a first bottom plate portion; 73. 273 flange part; 74. 274 an annular portion; 74a outer peripheral surface; 75. 275 a resin part; 80 bus bar; 171c a sealing member; 271 surrounding the cylinder part (cylinder part); 272 eave holding part; 276 a metal bracket part; 277a metal bottom plate portion; 278 eaves portion; 278a buried region; 278b exposed area; 279 metal cylinder part; 290 an elastic member; j central axis.

Claims

1. A motor, comprising:

a rotor that rotates about a central axis;

a stator radially opposite the rotor;

a housing made of resin and in which the stator is embedded;

a bearing that supports the rotor to be rotatable relative to the stator; and

a bearing holder that holds the bearing,

the bearing support has:

a resin portion that is made of resin and holds the bearing; and

a bus bar electrically connected with the coil of the stator,

the bus bar is embedded in the resin portion.

2. The motor of claim 1,

the bearing holder has a metal holder portion embedded in the resin portion,

the resin portion holds the bearing by the metal bracket portion.

3. The motor of claim 2,

the metal bracket part has:

a metal cylinder portion that surrounds the bearing from a radially outer side; and

a brim portion extending radially outward from one axial end of the metal tube portion,

the eaves portion has:

an embedded region embedded in the resin portion; and

an exposed region that is located radially inward of the embedded region and is exposed from the resin portion.

4. The motor of claim 3,

the resin part has:

an eave holding portion in which the eave portion is embedded;

an enclosing cylinder portion that extends from an outer edge of the eaves holding portion to the other axial side and that encloses the metal cylinder portion from a radially outer side with a gap therebetween; and

and a flange portion extending radially outward from an end portion on the other axial side of the surrounding cylinder portion.

5. The motor according to claim 3 or 4,

the metal bracket part has a metal bottom plate part extending radially inward from the end part on the other axial side of the metal tube part,

an elastic member is provided between the outer ring of the bearing and the metal bottom plate portion.

6. The motor of claim 5,

the elastic member is a wave washer.

7. The motor according to any one of claims 1 to 6,

the resin part has:

a cylindrical portion surrounding the bearing from a radially outer side; and

a flange portion that extends radially outward from the cylinder portion and is fixed to the housing.

8. The motor of claim 7,

the flange portion extends radially outward from an axial center portion of the cylindrical portion.

9. The motor according to claim 7 or 8,

the resin portion has an annular portion projecting from the flange portion toward one axial side,

the outer peripheral surface of the annular portion is in contact with an attachment inner peripheral surface that is provided on the housing and faces radially inward over the entire circumference.

10. The motor of claim 9,

the annular portion is located inward of an outer edge of the flange portion.

11. The motor according to claim 9 or 10,

the annular portion and the cylindrical portion are opposed to each other with a gap in the radial direction.