WO2020195399A1

WO2020195399A1 - Motor

Info

Publication number: WO2020195399A1
Application number: PCT/JP2020/006706
Authority: WO
Inventors: 裕也齋藤; 藤原　英雄; 尚石田; 梅田　智之
Original assignee: 日本電産株式会社
Priority date: 2019-03-28
Filing date: 2020-02-20
Publication date: 2020-10-01
Also published as: CN113439378A; CN113439378B

Abstract

One embodiment of the motor according to the present invention is provided with: a stator having a plurality of coils; a housing comprising a resin and having the stator embedded therein; and a plurality of bus bars located on one side of the stator in the axial direction. The plurality of coils include a first phase coil, a second phase coil, and a third phase coil arranged in this order toward the other side in the circumferential direction around the central axis. The first phase coil, the second phase coil, and the third phase coil have lead-out wires extending from lead-out portions located on one side in the circumferential direction with respect to the coils. The plurality of bus bars are categorized into a first phase bus bar connected to the lead-out wire of the first phase coil, a second phase bus bar connected to the lead-out wire of the second phase coil, and a third phase bus bar connected to the lead-out wire of the third phase coil. The first phase bus bar is supported by an insulator on which the second phase coil is mounted. The second phase bus bar is supported by an insulator on which the third phase coil is mounted. The third phase bus bar is supported by an insulator on which the first phase coil is mounted.

Description

motor

The present invention relates to a motor.

In recent years, motors in which the stator is molded with resin have been developed for the purpose of simplifying the assembly process. Patent Document 1 discloses a motor in which a resin portion for molding a stator constitutes a housing.

Japanese Publication: Japanese Patent Application Laid-Open No. 2007-267568

The motor is connected to the control device via a bus bar connected to the leader wire drawn from the coil, and power is supplied from the control device to the stator. When the stator is molded from a resin material, the assembly process can be further simplified by molding the bus bar together with the stator. However, if the length of the leader wire from the coil to the bus bar is non-uniform, the electrical resistance of the current path from the bus bar to the coil becomes non-uniform, which may impair the rotational stability of the motor.

In view of the above circumstances, one of the objects of the present invention is to provide a motor having improved rotational stability by making the lengths of a plurality of leader wires uniform.

One embodiment of the motor of the present invention comprises a rotor that rotates around a central axis, an insulator, a stator having a plurality of coils mounted on the insulator and facing the rotor in the radial direction, and a resin. A housing to be embedded and a plurality of bus bars located on one side in the axial direction of the stator are provided. The plurality of the coils are three-phase motors classified into a first-phase coil, a second-phase coil, and a third-phase coil, which are arranged in the following order toward the other side in the circumferential direction around the central axis. is there. The first-phase coil, the second-phase coil, and the third-phase coil have a leader wire extending from a leader portion located on one side in the circumferential direction with respect to the coil. The plurality of the bus bars are connected to the first phase bus bar connected to the leader wire of the first phase coil, the second phase bus bar connected to the leader wire of the second phase coil, and the leader wire of the third phase coil. It is classified into a phase 3 busbar. The first phase bus bar is supported by the insulator to which the second phase coil is mounted. The second phase bus bar is supported by the insulator to which the third phase coil is mounted. The third-phase busbar is supported by the insulator to which the first-phase coil is mounted.

According to one aspect of the present invention, a motor having improved rotational stability is provided by making the lengths of a plurality of leader wires uniformly close to each other.

FIG. 1 is a cross-sectional view of the motor of one embodiment. FIG. 2 is a perspective view of the bus bar and the stator of one embodiment, and is a view showing a state in which they are disassembled from each other. FIG. 3 is a perspective view of the bus bar and the stator of one embodiment, and is a diagram showing a state in which they are assembled to each other. FIG. 4 is a partial cross-sectional view showing a mold for molding the housing of one embodiment and a state of a stator in the mold. FIG. 5 is a schematic plan view of the stator and bus bar of one embodiment as viewed from below. FIG. 6 is a partial cross-sectional view of a motor having a modified bus bar.

Hereinafter, embodiments to which the present invention has been applied will be described in detail with reference to the drawings.
In the following description, the direction parallel to the central axis J (see FIG. 1) is simply referred to as "axial direction" or "vertical direction", and the radial direction centered on the central axis J is simply referred to as "radial direction". The circumferential direction around the axis J, that is, the circumference of the central axis J is simply referred to as the "circumferential direction". Further, in the present specification, one side in the axial direction along the central axis J is simply referred to as "lower side", and the other side is simply referred to as "upper side". It should be noted that the vertical direction in the present specification is merely a direction used for explanation, and does not limit the posture during use and distribution of the motor.

In the present specification, the side that advances counterclockwise when viewed from below, that is, the side that advances in the direction of arrow θ is referred to as "one side in the circumferential direction". The side that advances clockwise when viewed from the upper side to the lower side in the circumferential direction, that is, the side that advances in the direction opposite to the direction of the arrow θ is called "the other side in the circumferential direction".

FIG. 1 is a cross-sectional view of the motor 1 of one embodiment. As shown by a virtual line (dashed line) in FIG. 1, a control device 9 is attached to the lower side of the motor 1. The control device 9 supplies electric power to the motor 1. The motor 1 of this embodiment is a three-phase motor. The control device 9 supplies an alternating current to the motor 1.

The motor 1 includes a rotor 10, a stator 20 that surrounds the rotor 10, an upper bearing 15 and a lower bearing (bearing) 16 that rotatably hold the rotor 10 with respect to the stator 20, and an upper bearing that holds the upper bearing 15. It has a holder 40, a lower bearing holder (bearing holder) 70 for holding the lower bearing 16, a housing 30, and a plurality of bus bars 80.

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

The shaft 11 is rotatably supported around the central axis J by the upper bearing 15 and the lower bearing 16. The rotor core 12 is fixed to the outer peripheral surface of the shaft 11. Further, the rotor magnet 13 is fixed to the outer peripheral surface of the rotor core 12. The plurality of rotor magnets 13 may be embedded inside the rotor core 12.

The upper bearing 15 is located above the stator 20, and the lower bearing 16 is located below the stator 20. The upper bearing 15 supports the upper end of the shaft 11, and the lower bearing 16 supports the lower end of the shaft 11. That is, the upper bearing 15 and the lower bearing 16 rotatably support the rotor 10. The upper bearing 15 and the lower bearing 16 of the present embodiment are ball bearings. The upper bearing 15 and the lower bearing 16 may be other types of bearings such as needle bearings.

The upper bearing holder 40 is located above the stator 20. The upper bearing holder 40 is made of metal. The upper bearing holder 40 has a holder cylinder portion 41, an upper plate portion 42 extending radially inward from the upper end of the holder cylinder portion 41, and a holder flange portion 43 extending radially outward from the lower end of the holder cylinder portion 41. ..

The holder cylinder portion 41 has a cylindrical shape centered on the central axis J. The upper bearing 15 is arranged inside the holder cylinder portion 41 in the radial direction. 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 central hole 42a penetrating in the axial direction. The shaft 11 is inserted through the central hole 42a. The radial outer edge of the holder flange 43 is embedded in the housing 30. That is, at least a part of the upper bearing holder 40 is embedded in the housing 30.

The lower bearing holder 70 is located below the stator 20. The lower bearing holder 70 is made of resin. The lower bearing holder 70 has a disk shape when viewed from the axial direction. The lower bearing holder 70 is fixed to the housing 30 at the outer edge.

A central hole 72a is provided in the center of the lower bearing holder 70 when viewed from the axial direction. The lower end of the shaft 11 is inserted into the central hole 72a. An inner wall surface 71a that surrounds the lower bearing 16 from the outside in the radial direction and holds the lower bearing 16 is provided around the central hole 72a.

The stator 20 surrounds the rotor 10 from the outside in the radial direction. The stator 20 faces the rotor 10 in the radial direction. The stator 20 includes a stator core 21, a plurality of insulators 22, and a plurality of coils 29 mounted on the insulators.

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

The coil 29 is attached to the teeth portion 21b via the insulator 22. The end of the coil 29 is connected to a bus bar 80 located below the stator 20. The bus bar 80 is connected to a control device (not shown). Electric power is supplied to the coil 29 from the control device via the bus bar 80.

The insulator 22 is made of an insulating member. The insulator 22 is, for example, a resin member. The insulator 22 is attached to the teeth portion 21b. The insulator 22 is interposed between the teeth portion 21b and the coil 29. The insulator 22 has an upper piece 22A and a lower piece 22B. The upper piece 22A is attached to the stator core 21 from above. The upper piece 22A surrounds the upper end surface of the core back portion 21a and the upper half region of both end faces in the circumferential direction of the teeth portion 21b. The lower piece 22B is attached to the stator core 21 from below. The lower piece 22B surrounds the lower end surface of the core back portion 21a and the lower half region of both end faces in the circumferential direction of the teeth portion 21b.
In the present specification, the distal end surface of the teeth portion 21b is the surface of the teeth portions 21b that are orthogonal to the radial direction and the axial direction and face the circumferential direction, and the teeth portions 21b arranged along the circumferential direction face each other. It is a face.

The insulator 22 has an insulator main body portion 25, an inner wall portion 23, and an outer wall portion 24, respectively. The insulator main body 25 surrounds the entire outer peripheral surface of the teeth portion 21b. The insulator main body 25 is interposed between the outer peripheral surface of the teeth 21b and the coil 29.

The inner wall portion 23 is located inside the insulator main body portion 25 in the radial direction and extends along the circumferential direction. The inner wall portion 23 overlaps with the radial inner end portion of the teeth portion 21b when viewed from the axial direction. The inner wall portion 23 is located radially inside the coil 29. The inner wall portion 23 restricts the coil 29 wound around the teeth portion 21b from moving inward in the radial direction.

The inner wall portion 23 is provided on the upper piece 22A and the lower piece 22B, respectively. In the following description, the inner wall portion 23 of the upper piece 22A will be referred to as the upper inner wall portion 23A. Further, the inner wall portion 23 of the lower piece 22B is referred to as a lower inner wall portion 23B. The upper inner wall portion 23A extends upward with respect to the insulator main body portion 25. The lower inner wall portion 23B extends downward with respect to the insulator main body portion 25.

The outer wall portion 24 is located on the outer side in the radial direction of the insulator main body portion 25 and extends along the circumferential direction. The outer wall portion 24 overlaps with the core back portion 21a when viewed from the axial direction. The outer wall portion 24 is located radially outside the coil 29. The outer wall portion 24 restricts the coil 29 wound around the teeth portion 21b from moving outward in the radial direction.

The outer wall portion 24 is provided on the upper piece 22A and the lower piece 22B, respectively. In the following description, the outer wall portion 24 of the upper piece 22A will be referred to as the upper outer wall portion 24A. Further, the outer wall portion 24 of the lower piece 22B is referred to as a lower outer wall portion 24B. The upper outer wall portion 24A extends upward with respect to the insulator main body portion 25. The lower outer wall portion 24B extends downward with respect to the insulator main body portion 25. As will be described in detail later, the lower outer wall portion 24B is provided with a recess 24c into which the bus bar 80 is inserted.

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 a fiber reinforced resin material. Further, the housing 30 may be a thermosetting resin or a thermoplastic resin.

A stator 20, a bus bar 80, and an upper bearing holder 40 are embedded in the housing 30. As a result, the housing 30 holds the bus bar 80, the stator 20, and the upper bearing holder 40. The housing 30 is insert-molded with the stator 20, the bus bar 80, and the upper bearing holder 40 held in the mold. That is, since the stator 20, the bus bar 80, and the upper bearing holder 40 can be embedded in the housing 30 at once, the assembly process of the motor 1 is simplified.

The housing 30 includes a main body 31 that holds the stator 20, an upper annular portion 32 that is located above the main body 31, a bus bar holder 36 that holds the bus bar 80, and a lower portion that extends downward from the lower surface of the main body 31. A cylinder portion (cylinder portion) 37, a holding wall portion (wall portion) 39 located below the main body portion 31 and to which the lower bearing holder 70 is fixed, and a holder holding portion 38 for holding the upper bearing holder 40. Has.

The stator 20 is embedded in the main body 31. The main body 31 surrounds the upper side, the lower side, and the radial outer side with respect to the stator 20. The main body 31 surrounds the teeth portion 21b and the coil 29, and is also provided between the teeth portions 21b and the coil 29 that 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 upper annular portion 32 extends annularly in the circumferential direction. The upper annular portion 32 has a plurality of ribs 35 extending in the circumferential direction and the radial direction. As a result, the upper annular portion 32 reinforces the housing 30.

The lower cylinder portion 37 has a cylindrical shape centered on the central axis J. The lower cylinder portion 37 extends downward from the main body portion 31. The outer peripheral surface 37b of the lower cylinder portion 37 is continuous with the outer peripheral surface of the main body portion 31. The lower cylinder portion 37 surrounds the lower end portions of the plurality of bus bars 80 protruding from the housing 30 from the outside in the radial direction.

A control device 9 for controlling the motor 1 is attached to the lower cylinder portion 37. A socket portion 9a is provided on the upper surface of the control device 9. The socket portion 9a is a hole portion extending downward from the upper surface. The bus bar 80 is electrically connected to the control device 9 by being inserted into the socket portion 9a. Further, the control device 9 has a mounting surface 9b facing outward in the radial direction. The mounting surface 9b is a cylindrical surface centered on the central axis J. The mounting surface 9b fits into the inner peripheral surface 37a of the lower cylinder portion 37. Therefore, the inner peripheral surface 37a of the lower cylinder portion 37 functions as a surface for aligning the motor 1 and the control device 9 with each other.

The holding wall portion 39 projects downward from the lower surface of the main body portion 31. That is, the holding wall portion 39 is located below the stator 20. The holding wall portion 39 extends along the circumferential direction. The holding wall portion 39 is located inside the lower cylinder portion 37 and the bus bar holder portion 36 in the radial direction. A concave groove 39 g is provided between the holding wall portion 39 and the bus bar holder portion 36 on the surface facing the lower side of the housing 30. As a result, it is possible to suppress the local increase in the wall thickness of the housing 30 as compared with the case where the holding wall portion 39 and the bus bar holder portion 36 are connected, and it is possible to suppress sink marks on the housing 30.

The lower bearing holder 70 is fixed to the holding wall portion 39 by means such as heat caulking. The lower bearing holder 70 fits into the inner peripheral surface 39a of the holding wall portion 39. As a result, the lower bearing holder 70 is positioned in the radial direction with respect to the housing 30.

The bus bar holder portion 36 is located below the main body portion 31. The bus bar holder portion 36 is located inside the lower cylinder portion 37 in the radial direction. Six bus bars 80 are embedded inside the bus bar holder portion 36. The bus bar 80 projects downward from the lower surface of the bus bar holder portion 36.

The bus bar 80 is located below the stator 20. The bus bar 80 is made of a highly conductive metal material (for example, a copper-based alloy). The bus bar 80 has a plate shape. The bus bar 80 is formed by pressing a plate material.

The bus bar 80 is connected to a leader line 28 extending from the coil 29. The leader wire 28 is the end of the winding end of the coil 29 or the end of the winding end, and in the present embodiment, the leader wire 28 is the end of the winding end of the coil 29. In the present embodiment, the winding start end of the coil 29 is connected to a neutral point bus bar (not shown).

The bus bar 80 includes a leader wire connecting portion 81 connected to the leader wire 28, an external connecting terminal portion 82 extending downward from the leader wire connecting portion 81, and a supported portion 83 extending upward from the leader wire connecting portion 81. Has.

The leader wire connecting portion 81 has a base portion 81a, a folded-back portion 81b folded back from the upper end portion of the base portion 81a, and a bent portion 81c located at the lower end of the folded-back portion 81b. The leader wire connecting portion 81 is connected to the external connecting terminal portion 82 and the supported portion 83 at the base portion 81a.

The base portion 81a and the folded portion 81b extend substantially parallel to the axial direction with the radial direction as the plate thickness direction. The base portion 81a and the folded portion 81b face each other in the radial direction. In the present embodiment, the folded-back portion 81b is located radially outward with respect to the base portion 81a. Two leader lines 28 are sandwiched between the base portion 81a and the folded-back portion 81b.

The bent portion 81c extends downward from the lower end of the folded portion 81b. The bent portion 81c inclines toward the base portion 81a side toward the lower side. The distance between the lower end of the bent portion 81c and the base portion 81a is smaller than the wire diameter of the leader wire 28. Further, the lower end of the bent portion 81c may be in contact with the base portion 81a. The bent portion 81c suppresses the leader line 28 from coming off from the region sandwiched between the base portion 81a and the folded portion 81b.

The base portion 81a, the folded-back portion 81b, and the two leader wires 28 are fixed to each other by welding, for example, and are electrically connected to each other. Specifically, with the leader wire 28 sandwiched between the base portion 81a and the folded-back portion 81b, the base portion 81a and the folded-back portion 81b are sandwiched between two electrodes and welded by passing an electric current. However, the connection between the leader wire connecting portion 81 and the leader wire 28 is not limited to resistance welding. For example, it may be fixed by welding other than resistance welding such as arc welding, soldering, or adhesion with a conductive adhesive.

The external connection terminal portion 82 extends along the axial direction with the radial direction as the plate thickness direction. The upper end of the external connection terminal portion 82 is connected to the base portion 81a of the leader wire connection portion 81. The upper end of the external connection terminal portion is embedded in the housing 30. Further, the lower end of the external connection terminal portion 82 is exposed from the housing 30.

The supported portion 83 is supported by the insulator 22. Therefore, the bus bar 80 can be temporarily fixed to the stator 20 in a state before the housing 30 is molded. As a result, the work of holding the stator 20 and the bus bar 80 before molding in the mold for molding the housing 30 becomes easy.

FIG. 2 is a perspective view of the bus bar 80 and the stator 20 and shows a state in which they are disassembled from each other. Further, FIG. 3 is a perspective view of the bus bar 80 and the stator 20 and shows a state in which they are assembled to each other.

As shown in FIG. 2, the supported portion 83 has a pair of leg portions 83a. The leg portion 83a extends axially from the base portion 81a with the radial direction as the plate thickness direction. The pair of legs 83a are arranged along the circumferential direction. The pair of legs 83a each have an outer surface 83ab facing away from each other.

The insulator 22 has a recess 24c that opens downward. The recess 24c of the present embodiment is a through hole that penetrates the insulator 22 in the axial direction. The recess 24c has a rectangular shape in which the long side extends along the circumferential direction and the short side extends along the radial direction when viewed from the axial direction. The recess 24c has a pair of facing surfaces 24cc that face each other in the circumferential direction. The pair of facing surfaces 24cc form the short side of the recess 24c when viewed from the axial direction. The distance dimension between the pair of facing surfaces 24 cc is slightly smaller than the distance dimension between the pair of outer surface 83 abs.

As shown in FIG. 3, the pair of leg portions 83a are inserted into the recess 24c of the insulator 22. The pair of facing surfaces 24cc of the recess 24c come into contact with the outer surfaces 83ab of the different legs 83a. The pair of legs 83a are pressed against different facing surfaces 24cc and elastically deformed in a direction approaching each other. Surface pressure is applied to the outer side surface 83ab and the facing surface 24cc, and the supported portion 83 is stably supported by the insulator 22 in the recess 24c due to frictional resistance. Therefore, in the manufacturing process, it is possible to prevent the bus bar 80 from being separated from the stator 20 until the molding process of embedding the bus bar 80 in the housing 30 is performed.

FIG. 4 is a partial cross-sectional view showing a state of the mold 90 for molding the housing 30 and the stator 20 in the mold 90.

Inside the mold 90, a cavity C filled with a resin material constituting the housing 30 is provided. The mold 90 has a first mold 91 and a second mold 92 that surround the cavity C. The first type 91 and the second type 92 are arranged so as to face each other in the axial direction. The second type 92 is located below the first type 91. The first type 91 and the second type 92 are relatively separable vertically on the parting line PL. In the present embodiment, the parting line PL is arranged on the same plane as the lower end surface of the stator core 21.

The first type 91 is an area on the upper side of the parting line PL, and forms the main body portion 31, the upper annular portion 32, and the holder holding portion 38. On the other hand, the second type 92 is a region below the parting line PL and forms the bus bar holder portion 36 and the lower cylinder portion 37.

The second type 92 has a first annular groove 92a, a second annular groove 92c, and a holding recess 92b that open upward. Further, the second type 92 has an inner block 92h and an outer block 92j that can be separated from each other on the separation surface 92p extending downward from the bottom surface of the first annular groove 92a. The inner block 92h has a circular outer peripheral surface in a plan view, and the outer block 92j has an inner peripheral surface in a circular shape in a plan view. The second type 92 is configured by fitting the inner peripheral surface of the inner block 92h to the outer peripheral surface of the outer block 92j. As a result, the inner block 92h and the outer block 92j are aligned with each other with high accuracy.

The first annular groove 92a is recessed downward and extends along the circumferential direction. The resin filled in the first annular groove 92a constitutes the lower cylinder portion 37 of the housing 30. The first inner wall surface 92aa facing the radial outer side of the first annular groove 92a is one surface of the inner block 92h. Further, the second inner wall surface 92ab facing the radial inward side of the first annular groove 92a is one surface of the outer block 92j. The inner block 92h forms the inner peripheral surface 37a of the lower cylinder portion 37 on the first inner wall surface 92aa. Further, the outer block 92j forms the outer peripheral surface 37b of the second inner wall surface 92ab lower cylinder portion 37.

The holding recess 92b is arranged inside the first annular groove 92a in the radial direction. The holding recess 92b is provided in the inner block 92h. The holding recess 92b holds the recessed bus bar 80 on the lower side. When viewed from the axial direction, the shape of the holding recess 92b substantially matches the cross-sectional shape of the external connection terminal portion 82 of the bus bar 80. The housing 30 is formed in a state where the tip of the external connection terminal portion 82 is held by the holding recess 92b of the mold 90. As a result, the tip of the bus bar 80 can be exposed from the housing 30, and the positioning accuracy of the bus bar 80 with respect to the housing 30 can be improved.

The second type has a tapered surface 92ba located at the opening of the holding recess 92b. The tapered surface 92ba surrounds the opening of the holding recess 92b when viewed from the axial direction. The tapered surface 92ba is inclined downward as it approaches the opening of the holding recess 92b. The tapered surface 92ba invites the external connection terminal portion 82 into the holding recess 92b in the step of inserting and holding the bus bar 80 into the holding recess 92b. Therefore, by providing the tapered surface 92ba, the external connection terminal portion 82 can be inserted into the holding recess 92b without causing damage.

As shown in FIG. 1, the bus bar holder portion 36 of the housing 30 has a raised portion 36a that protrudes downward (one side in the axial direction). The raised portion 36a is a region formed by the tapered surface 92ba. Therefore, the external connection terminal portion 82 projects downward from the bus bar holder portion 36 at the raised portion 36a. Further, in the present embodiment, the external connection terminal portion 82 projects downward from the bus bar holder portion 36 at the top of the raised portion 36a.

According to the present embodiment, the bus bar 80 has an external connection terminal portion 82 exposed from the housing 30. Further, the lower cylinder portion 37 surrounds the external connection terminal portion 82 from the outside in the radial direction. The inner peripheral surface 37a of the lower cylinder portion 37 comes into contact with the mounting surface 9b of the control device 9 and functions as a surface for aligning the control device 9 with respect to the motor 1. According to the present embodiment, since the lower cylinder portion 37 surrounds the external connection terminal portion 82 from the outside in the radial direction, the external connection terminal portion 82 is formed while molding the lower cylinder portion 37 by one mold (second type 92). Can be retained. In particular, in the present embodiment, the external connection terminal portion 82 is held while forming the inner peripheral surface 37a of the lower cylinder portion 37 by the same block (inner block 92h). As a result, the positional accuracy of the external connection terminal portion 82 with respect to the inner peripheral surface 37a of the lower cylinder portion 37 can be improved, and the bus bar 80 can be smoothly inserted into the socket portion 9a of the control device 9.

The second annular groove 92c is arranged inside the first annular groove 92a and the holding recess 92b in the radial direction. The second annular groove 92c is recessed downward and extends along the circumferential direction. The second annular groove 92c is provided in the inner block 92h. The resin filled in the second annular groove 92c constitutes the holding wall portion 39 of the housing 30.

As described above, the lower bearing holder 70 fits into the inner peripheral surface 39a of the holding wall portion 39. Therefore, the holding wall portion 39 supports the shaft 11 via the lower bearing holder 70 and the lower bearing 16. According to this embodiment, the inner peripheral surface of the holding wall portion 39 and the inner peripheral surface 37a of the lower cylinder portion 37 can be formed by the same block (inner block 92h). Therefore, the positional accuracy of the inner peripheral surface 37a of the lower cylinder portion 37 can be improved with respect to the inner peripheral surface 37a of the lower cylinder portion 37. As a result, the positional accuracy of the shaft 11 with respect to the control device 9 attached to the lower cylinder portion 37 can be improved.

Next, the state in which the leader line 28 is arranged in the stator 20 of the present embodiment will be described in detail.
FIG. 5 is a schematic plan view of the stator 20 and the bus bar 80 as viewed from below. The stator 20 of the present embodiment has four systems of three-phase circuits. Each three-phase circuit is composed of star connections. The terminals at the beginning of winding of all the coils 29 are connected to the neutral point bus bar (not shown) as the neutral point of the four-system three-phase circuit, and have the same potential.

In this embodiment, the stator 20 has 12 coils 29. The 12 coils 29 consist of 4 U-phase coils (1st phase coil) 29U, 4 V-phase coils (2nd phase coil) 29V, and 4 W-phase coils (3rd phase coil) 29W. And, it is classified into. The U-phase coil 29U, the V-phase coil 29V, and the W-phase coil 29W are arranged in this order toward the other side in the circumferential direction (clockwise in FIG. 1) around the central axis J.

Each of the plurality of coils 29 has a leader wire 28 extending from the leader portion 27 of the coil 29. In the present embodiment, the extraction portions 27 of all the coils 29 (U-phase coil 29U, V-phase coil 29V, and W-phase coil 29W) are located on one side in the circumferential direction with respect to the coil 29.

According to the present embodiment, the extraction portions 27 of all the coils 29 are located on one side in the circumferential direction with respect to the coils 29. Further, the leader wire 28 drawn from these leaders 27 is a terminal at the end of winding of the coil 29. Therefore, the winding configurations such as the winding direction and the winding end position of all the coils 29 can be the same. As a result, the winding can be performed without distinguishing the plurality of coils 29, and the manufacturing process can be simplified.

In the present embodiment, six bus bars 80 are attached to the stator 20. The six busbars 80 are two U-phase busbars (first-phase busbars) 80U, two V-phase busbars (second-phase busbars) 80V, and two W-phase busbars (third-phase busbars) 80W. And, it is classified into. The U-phase bus bar 80U, the V-phase bus bar 80V, and the W-phase bus bar 80W are arranged in the following order toward the other side in the circumferential direction around the central axis J.

Two leader wires 28 having the same phase are connected to the bus bar 80 at the leader wire connecting portion 81. That is, two leader wires 28 extending from two in-phase coils 29 are connected to the leader wire connecting portion 81 of one bus bar 80.

The U-phase bus bar 80U, the V-phase bus bar 80V, and the W-phase bus bar 80W are compatible bus bars. The control device 9 supplies an alternating current to each bus bar 80. The phases of the alternating current supplied to each bus bar 80 are 120 ° out of phase.

The two three-phase circuits are connected in parallel by the bus bar 80. Therefore, a group of bus bars 80 composed of one U-phase bus bar 80U, one V-phase bus bar 80V, and one W-phase bus bar 80W supplies power to two three-phase circuits at the same time. Further, a group of bus bars 80 composed of one U-phase bus bar 80U, one V-phase bus bar 80V, and one W-phase bus bar 80W constitutes one input system. Therefore, the motor 1 of the present embodiment has two input systems.

The U-phase bus bar 80U is supported by the insulator 22 on which the V-phase coil 29V is mounted. Two leader lines 28, a first leader line 28Ua extending from one side in the circumferential direction and a second leader line 28Ub extending from the other side in the circumferential direction, are connected to the U-phase bus bar 80U.

The first leader line 28Ua is drawn from the U-phase coil 29U located on one side in the circumferential direction with respect to the connected U-phase bus bar 80U. The first leader line 28Ua is routed from the leader portion 27 toward the other side in the circumferential direction and is connected to the U-phase bus bar 80U. The first leader wire 28Ua passes under the drawn U-phase coil 29U, is routed radially outward of the V-phase coil 29V, and is connected to the U-phase bus bar 80U. Therefore, the length of the first leader line 28Ua extending along the circumferential direction is 1.5 of the length (coil width) of the coils 29 in the circumferential direction.

The second leader line 28Ub is drawn from the U-phase coil 29U located on the opposite side in the circumferential direction with respect to the connected U-phase bus bar 80U. The second leader line 28Ub is routed from the leader portion 27 toward one side in the circumferential direction and is connected to the U-phase bus bar 80U. The second leader wire 28Ub passes through the radially outer side of the drawn W-phase coil 29W, is routed outward in the radial direction of the V-phase coil 29V, and is connected to the U-phase bus bar 80U. Therefore, the length of the second leader line 28Ub extending along the circumferential direction is 1.5 of the length (coil width) of the coils 29 in the circumferential direction.

The position of the leader line connecting portion 81 of the U-phase bus bar 80U in the circumferential direction is an intermediate point between the leader portions 27 of the two leader lines (first leader line 28Ua and second leader line 28Ub). Therefore, the distances from the leader line connecting portion 81 to the two leader portions 27 are the same. As a result, the lengths of the first leader line 28Ua and the second leader line 28Ub can be made substantially the same.

The V-phase bus bar 80V is supported by the insulator 22 on which the W-phase coil 29W is mounted. The leader line 28 connected to the V-phase bus bar 80V has the same configuration as the leader line 28 connected to the U-phase bus bar 80U described above.

Two leader lines 28, a first leader line 28V extending from one side in the circumferential direction and a second leader line 28Vb extending from the other side in the circumferential direction, are connected to the V-phase bus bar 80V. The first leader line 28V is drawn from the V-phase coil 29V located on one side in the circumferential direction with respect to the connected V-phase bus bar 80V. The first leader line 28V passes under the V-phase coil 29V and is connected to the V-phase bus bar 80V. The second leader line 28Vb is drawn from the V-phase coil 29V located on the opposite side in the circumferential direction with respect to the connected V-phase bus bar 80V. The second leader wire 28Vb passes through the radial outside of the U-phase coil 29U and is connected to the V-phase bus bar 80V. The position of the leader line connecting portion 81 of the V-phase bus bar 80V in the circumferential direction is an intermediate point between the leader portions 27 of the two leader lines (first leader line 28V and second leader line 28Vb). Therefore, the lengths of the first leader line 28Va and the second leader line 28Vb can be made substantially the same.

The W-phase bus bar 80W is supported by the insulator 22 on which the U-phase coil 29U is mounted. The leader line 28 connected to the W-phase bus bar 80W has the same configuration as the leader line 28 connected to the U-phase bus bar 80U described above.

Two leader lines 28, a first leader line 28W extending from one side in the circumferential direction and a second leader line 28Wb extending from the other side in the circumferential direction, are connected to the W-phase bus bar 80W. The first leader line 28W is drawn from the W-phase coil 29W located on one side in the circumferential direction with respect to the connected W-phase bus bar 80W. The first leader line 28W passes under the W-phase coil 29W and is connected to the W-phase bus bar 80W. The second leader line 28Wb is drawn from the W-phase coil 29W located on the opposite side in the circumferential direction with respect to the connected W-phase bus bar 80W. The second leader wire 28Wb passes through the radial outside of the V-phase coil 29V and is connected to the W-phase bus bar 80W. The position of the leader line connecting portion 81 of the W-phase bus bar 80W in the circumferential direction is an intermediate point between the leader portions 27 of the two leader lines (first leader line 28W and second leader line 28Wb). Therefore, the lengths of the first leader line 28Wa and the second leader line 28Wb can be made substantially the same.

According to this embodiment, the lengths of the leader lines 28 connected to the bus bars 80 of different phases are the same. Since the electrical resistance of the leader line 28 is proportional to the length, the amplitudes of the magnetic fields of the coils 29 having different phases can be brought close to each other. As a result, the rotation of the motor 1 can be stabilized.

According to this embodiment, the lengths of the two leader lines 28 connected to the bus bars 80 of the same phase can be matched with each other. Therefore, the amplitudes of the magnetic fields of the coils 29 having the same phase can be brought close to each other, and the rotation of the motor 1 can be stabilized.

The leader line 28 is embedded in the housing 30 together with the stator 20 and the bus bar 80. Therefore, if the path of the leader line 28 becomes complicated, the resin cannot sufficiently wrap around between the leader lines 28, and there is a possibility that the leader line 28 is not sufficiently fixed by the housing 30. According to the present embodiment, by connecting the coils 29 having the same phase in parallel, the path of the leader line 28 can be shortened and the path of the leader line 28 can be simplified as compared with the case where the coils 29 are connected in series. .. As a result, the resin can be sufficiently wrapped around the leader wire 28.

According to this embodiment, two in-phase coils 29 are connected in parallel by one bus bar 80. Therefore, the number of bus bars 80 can be reduced and the number of parts of the motor 1 can be reduced as compared with the case where one bus bar 80 is connected to one coil 29.

According to the present embodiment, of the two leader wires 28 connected to the bus bar 80, one extending from one side in the circumferential direction passes under the coil 29 having the same phase, and the other extending from the other side in the circumferential direction is many. It passes the radial outside of the phase coil 29. This point will be described in detail focusing on the first leader line 28Va and the second leader line 28Vb connected to the V-phase bus bar 80V.

The first leader line 28V passes under the in-phase V-phase coil 29V. That is, the first leader line 28V overlaps with the V-phase coil 29V when viewed from the axial direction. Since the first leader line 28V is a V-phase coil 29V and a V-phase, by arranging the first leader wire 28V close to the V-phase coil 29V, no electrical problem occurs even if a short circuit occurs. On the other hand, the leader wire 28 of the other phase is arranged sufficiently away from the V-phase coil 29V in order to prevent short-circuiting with the V-phase coil 29V. Therefore, according to the present embodiment, it is possible to secure the distance between the first leader line 28Va and the leader line 28 of the other phase. Therefore, not only the short circuit with the other phase can be suppressed, but also the leader wires 28 can be suppressed from being densely packed, and the resin filling rate can be increased in the molding process of the housing 30.

The second leader wire 28Vb passes outside in the radial direction of the U-phase coil 29U of the other phase. That is, the second leader line 28Vb passes through a position different from that of the coil 29 of the other phase when viewed from the axial direction. As a result, it is possible to prevent the second leader wire 28Vb from being short-circuited with the coil 29 of the other phase.

As shown in FIG. 3, the two leader lines 28 connected to the bus bar 80 extend along the circumferential direction and line up in the axial direction. According to the present embodiment, the leader line 28 routed along the circumferential direction can be smoothly connected to the bus bar 80, and the route of the leader line 28 can be simplified. In addition, since the two leader wires 28 are lined up in the axial direction, it is possible to prevent the leader wire connecting portion 81 of the bus bar 80 from becoming enlarged in the radial direction, and it becomes easier to secure a distance from the leader wires 28 of other phases. ..

As shown in FIG. 1, the bus bar 80 is located outside the radial outer end of the coil 29. The rotor 10 is arranged inside the stator 20 in the radial direction. Therefore, when the bus bar 80 is arranged inside the coil 29 in the radial direction, a structure for suppressing the leader wire 28 from protruding toward the rotor 10 is required. According to this embodiment, by arranging the bus bar 80 on the radial side of the coil 29, the interference between the leader wire 28 and the rotor 10 can be easily suppressed.

According to the present embodiment, the folded-back portion 81b of the bus bar 80 is located radially outside the base portion 81a. Therefore, it is possible to secure a distance between the bus bar 80 and the coil 29 located inside the bus bar in the radial direction at the folded-back portion to prevent short-circuiting with each other.

Next, a modified example of the above-described embodiment will be described. The components having the same aspects as those of the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted.
<Modification example of bus bar>
FIG. 6 is a partial cross-sectional view of a motor having a modified bus bar 180.
The bus bar 180 of this modification is mainly different in the configuration of the leader line connecting portion 181 as compared with the above-described embodiment.

Similar to the above-described embodiment, the bus bar 180 of the present modification has a leader wire connection portion 181 connected to the leader wire 28, an external connection terminal portion 82 extending downward from the leader wire connection portion 181 and a leader wire connection. It has a supported portion 83 extending upward from the portion 181.

The leader wire connecting portion 181 has a base portion 181a, a folded-back portion 181b folded back from the upper end portion of the base portion 181a, and a bent portion 181c located at the lower end of the folded-back portion 181b. The base portion 181a and the folded portion 181b extend substantially in parallel along the axial direction with the radial direction as the plate thickness direction. The folded-back portion 181b is located radially inward with respect to the base portion 181a. Two leader lines 28 are sandwiched between the base portion 181a and the folded-back portion 181b. The bent portion 181c suppresses the leader line 28 from coming off from the region sandwiched between the base portion 181a and the folded portion 181b.

According to this modification, the folded-back portion 181b is located radially inward with respect to the base portion 181a. Therefore, the leader wire connecting portion 181 can be brought closer to the coil 29 in the radial direction, and the leader wire 28 extending from the coil 29 can be shortened.

Although one embodiment of the present invention and a modification thereof have been described above, each configuration and a combination thereof in the embodiment and the modified example are examples, and the configuration is added within a range not deviating from the gist of the present invention. , Omission, replacement and other changes are possible. Moreover, the present invention is not limited to the embodiments.

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

1 ... motor, 10 ... rotor, 20 ... stator, 22 ... insulator, 27 ... leader, 28 ... leader wire, 29 ... coil, 29U ... U-phase coil (first phase coil), 29V ... V-phase coil (second phase coil) Phase coil), 29W ... W phase coil (third phase coil), 30 ... housing, 80, 180 ... bus bar, 80U ... U phase bus bar (first phase bus bar), 80V ... V phase bus bar (second phase bus bar), 80W ... W phase bus bar (third phase bus bar), 81,181 ... Leader connection part, 81a, 181a ... Base part, 81b, 181b ... Folded part, J ... Central axis

Claims

A rotor that rotates around the central axis and
An insulator and a stator having a plurality of coils mounted on the insulator and facing the rotor in the radial direction,
A housing made of resin and in which the stator is embedded,
A plurality of bus bars located on one side in the axial direction of the stator are provided.
The plurality of the coils are three-phase motors classified into a first-phase coil, a second-phase coil, and a third-phase coil, which are arranged in the following order toward the other side in the circumferential direction around the central axis. There,
The first-phase coil, second-phase coil, and third-phase coil have a leader wire extending from a leader portion located on one side in the circumferential direction with respect to the coil.
The plurality of busbars
The first phase bus bar connected to the leader wire of the first phase coil,
The second phase bus bar connected to the leader wire of the second phase coil,
It is classified into a phase 3 bus bar connected to the leader wire of the phase 3 coil.
The first phase bus bar is supported by the insulator to which the second phase coil is mounted.
The second phase bus bar is supported by the insulator to which the third phase coil is mounted.
The third-phase busbar is supported by the insulator to which the first-phase coil is mounted.
motor.
The first phase bus bar includes the leader wire of the first phase coil located on one side in the circumferential direction with respect to the first phase bus bar, and the first line located on the other side in the circumferential direction with respect to the first phase bus bar. The leader wire of the phase coil is connected and
The second phase bus bar includes the leader wire of the second phase coil located on one side in the circumferential direction with respect to the second phase bus bar, and the second line located on the other side in the circumferential direction with respect to the second phase bus bar. The leader wire of the phase coil is connected and
The third phase bus bar includes the leader wire of the third phase coil located on one side in the circumferential direction with respect to the third phase bus bar, and the third phase position on the other side in the circumferential direction with respect to the third phase bus bar. The motor according to claim 1, wherein the leader wire of the phase coil is connected.
The motor according to claim 2, wherein the bus bar is connected to the two leader wires extending along the circumferential direction and lining up in the axial direction.
The motor according to any one of claims 1 to 3, wherein the bus bar is located outside the radial outer end of the coil.
For the first phase busbar
The leader wire of the first phase coil located on one side in the circumferential direction passes through one side in the axial direction of the first phase coil and is connected to the first phase bus bar.
The leader wire of the first phase coil located on the other side in the circumferential direction passes through the radial outside of the third phase coil and is connected to the first phase bus bar.
For the phase 2 busbar
The leader wire of the second phase coil located on one side in the circumferential direction passes through one side in the axial direction of the second phase coil and is connected to the second phase bus bar.
The leader wire of the second phase coil located on the other side in the circumferential direction passes through the radial outside of the first phase coil and is connected to the second phase bus bar.
For the phase 3 busbar
The leader wire of the third-phase coil located on one side in the circumferential direction passes through one side in the axial direction of the third-phase coil and is connected to the third-phase bus bar.
The motor according to claim 4, wherein the leader wire of the third phase coil located on the other side in the circumferential direction passes through the radial outside of the second phase coil and is connected to the first phase bus bar.
The bus bar is plate-shaped and has a base and a folded portion that is folded back from the end of the base.
The motor according to any one of claims 1 to 5, wherein the leader wire is sandwiched between the base portion and the folded portion.
The motor according to claim 6, wherein the folded-back portion is located radially outside the base portion.
The motor according to claim 6, wherein the folded-back portion is located radially inside the base portion.
The motor according to any one of claims 1 to 8, wherein the leader wire is the end of the winding end of the coil.