WO2019065452A1 - Busbar unit and motor - Google Patents

Abstract

This busbar unit provided in a motor comprises: a busbar holder provided above a stator and arranged in an annular shape around a vertically extending central shaft; a first busbar fixed to one side of the busbar holder in an axial direction; and a second busbar fixed to the other side of the busbar holder in the axial direction, wherein: the busbar holder is composed of a resin material; the busbar holder has a busbar holder body section positioned, in the axial direction, between the first busbar and the second busbar, and a weld section for fixing the second busbar; and the weld section is arranged so as to be offset from the first busbar when viewed in the axial direction.

Description

Busbar unit and motor

The present invention relates to a bus bar unit and a motor.

Patent Document 1 discloses a structure in which bus bars are disposed above and below a bus bar holder.

China Utility Model No. 205123457 Specification

By arranging the bus bars above and below the bus bar holder as in Patent Document 1, the bus bars arranged above and below can be insulated by the bus bar holder. Conventionally, in such a structure, the bus bar is fixed by a welding portion which melts a part of the bus bar holder like heat caulking. When the bus bar is fixed by the welded portion, the bus bar holder may be deformed by the influence of heat. For this reason, there existed a problem that the positional accuracy of the bus-bar with respect to a bus-bar holder could not be improved in the other side of a welding part.

In view of the above problems, one aspect of the present invention aims to provide a bus bar unit in which the positional accuracy of the bus bar with respect to the bus bar holder is enhanced, and a motor including the bus bar unit.

The bus bar unit of the present invention is a bus bar unit provided to a motor, and is fixed to one side of the bus bar holder in the axial direction of the bus bar holder provided on the upper side of the stator annularly arranged around a central axis extending in the vertical direction. And the second bus bar fixed to the other axial side of the bus bar holder, wherein the bus bar holder is made of a resin material, and the A bus bar holder main body positioned between the first bus bar and the second bus bar, and a welded portion for fixing the second bus bar, the welded portion being viewed from the axial direction; It is disposed off the bus bar of

According to one aspect of the present invention, it is possible to provide a bus bar unit in which the positional accuracy of the bus bar with respect to the bus bar holder is enhanced. Further, according to one aspect of the present invention, it is possible to provide a motor that easily connects the lead wire of the coil to the bus bar unit.

FIG. 1 is a cross-sectional view of a motor according to one embodiment. FIG. 2 is a plan view of a stator of one embodiment. FIG. 3 is a schematic view showing connection of each coil of the stator of the embodiment. FIG. 4 is a schematic view showing two systems of Y-connections configured by the coil of one embodiment. FIG. 5 is a perspective view of the bus bar unit of one embodiment. FIG. 6 is an exploded perspective view of the bus bar unit according to one embodiment. FIG. 7 is a plan view of the bus bar unit of one embodiment. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. FIG. 9 is a bottom view of the bus bar unit of one embodiment. FIG. 10 is a schematic cross-sectional view along the line XX in FIG. FIG. 11 is a schematic view showing an electric power steering apparatus according to an embodiment.

Hereinafter, a motor according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure intelligible, a scale, the number, etc. in an actual structure and each structure may be varied.

In each drawing, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system as appropriate. In the XYZ coordinate system, the Z-axis direction is a direction parallel to the axial direction of the central axis J shown in FIG. The X-axis direction is a direction orthogonal to the Z-axis direction, which is the left-right direction in FIG. The Y-axis direction is orthogonal to both the X-axis direction and the Z-axis direction.

In the following description, the positive side in the Z-axis direction (+ Z side) is referred to as “upper side”, and the negative side in the Z-axis direction (−Z side) is referred to as “lower side”. Note that the upper and lower sides are directions used merely for the purpose of explanation, and do not limit the actual positional relationship or direction. Further, unless otherwise noted, a direction (Z-axis direction) parallel to the central axis J is simply referred to as “axial direction” or “vertical direction”, and a radial direction centered on the central axis J is simply referred to as “radial direction”. The circumferential direction around the central axis J, that is, around the axis of the central axis J, is simply referred to as “circumferential direction”. Furthermore, in the following description, “plan view” means a state viewed from the axial direction.

[Motor] FIG. 1 is a cross-sectional view of a motor 1 of the present embodiment. The motor 1 of the present embodiment is a three-phase alternating current motor. Further, the motor 1 of the present embodiment is an inner rotor type motor.

The motor 1 includes a rotor 20 having a shaft 21, a stator 30, a bus bar unit 60, a housing 40, an upper bearing 6A, a lower bearing 6B, and a bearing holder 10. The motor 1 is connected to an external device (control unit) 9 by external connection terminals 71 c, 72 c, 73 c extending upward from the bus bar unit 60. The rotation of the rotor 20 is controlled by the external device 9 of the motor 1.

[Housing] The housing 40 is in the form of a cylinder that opens to the upper side (+ Z side). The housing 40 accommodates the rotor 20 and the stator 30. The housing 40 has a cylindrical portion 45, a bottom portion 49, and a lower bearing holding portion 48.

The cylindrical portion 45 surrounds the stator 30 from the radially outer side. In the present embodiment, the cylindrical portion 45 is cylindrical with the central axis J as a center. The bottom portion 49 is located at the lower end of the cylindrical portion 45. The bottom 49 is located below the stator 30. The lower bearing holding portion 48 is located at the center of the bottom portion 49 in plan view. The lower bearing holder 48 holds the lower bearing 6B. The lower bearing holding portion 48 has a holding cylindrical portion 48a extending in the axial direction centering on the central axis J, and a lower end protruding portion 48b extending inward in the radial direction from the lower end of the holding cylindrical portion 48a. A hole 48c penetrating in the axial direction is provided at the center of the lower end protrusion 48b in plan view.

[Rotor] The rotor 20 rotates around the central axis J. The rotor 20 has a shaft 21, a rotor core 24, and a rotor magnet 23. The shaft 21 is disposed along the central axis J around a central axis J extending in the vertical direction (axial direction). The shaft 21 is rotatably supported around the central axis J by the upper bearing 6A and the lower bearing 6B.

The rotor core 24 is fixed to the shaft 21. The rotor core 24 circumferentially surrounds the shaft 21. The rotor magnet 23 is fixed to the rotor core 24. More specifically, the rotor magnet 23 is fixed to the outer surface along the circumferential direction of the rotor core 24. The rotor core 24 and the rotor magnet 23 rotate with the shaft 21.

[Upper Bearing and Lower Bearing] The upper bearing 6A rotatably supports the shaft 21 provided on the rotor 20 at the upper side of the rotor core 24. The upper bearing 6A is supported by the bearing holder 10. The lower bearing 6B rotatably supports a shaft 21 provided on the rotor 20 at the lower side of the rotor core 24. The lower bearing 6B is supported by the lower bearing holding portion 48 of the housing 40.

[Bearing Holder] The bearing holder 10 is located on the upper side (+ Z side) of the stator 30. Further, the bearing holder 10 is located above the bus bar unit 60 described later. The bearing holder 10 holds the upper bearing 6A. Also, the bearing holder 10 is held by the cylindrical portion 45 of the housing 40. The planar view (XY plane) shape of the bearing holder 10 is, for example, a circular shape concentric with the central axis J.

The bearing holder 10 includes a disc-shaped bearing holder main body portion 16, an upper bearing holding portion 18 positioned radially inward of the bearing holder main body portion 16, and a fitting cylinder positioned radially outward of the bearing holder main body portion 16. And a unit 15. The upper bearing holding portion 18, the bearing holder main body portion 16 and the fitting cylindrical portion 15 are disposed in this order from the radially inner side to the outer side.

The bearing holder body 16 extends along a plane perpendicular to the axial direction. The bearing holder main body portion 16 is provided with a through hole 16a through which the external connection terminals 71c, 72c, 73c of the bus bar unit 60 are inserted.

The upper bearing holder 18 holds the upper bearing 6A. The upper bearing holder 18 is located at the center of the bearing holder 10 in plan view. The upper bearing holding portion 18 has a holding cylindrical portion 18a extending in the axial direction centering on the central axis J, and an upper end protruding portion 18b extending inward in the radial direction from the upper end of the holding cylindrical portion 18a. The upper end protrusion 18b positions the upper bearing 6A in the vertical direction. A hole 18c penetrating in the axial direction is provided at the center of the upper end protrusion 18b in a plan view. The upper end portion of the shaft 21 is inserted into the hole 18c.

The fitting cylindrical portion 15 extends downward from the outer edge of the bearing holder main body 16. The fitting cylindrical portion 15 extends in a tubular shape along the circumferential direction. The fitting cylindrical portion 15 is engaged with the inner peripheral surface 45 c of the cylindrical portion 45 in the radial direction. Thus, the bearing holder 10 is fixed to the housing 40.

[Stator] The stator 30 is annularly disposed around the central axis J. The stator 30 radially faces the rotor 20 via a gap. The stator 30 surrounds the radially outer side of the rotor 20. The stator 30 is fixed to the inner circumferential surface 45 c of the cylindrical portion 45 of the housing 40. The stator 30 has a stator core 31, an upper insulator 35, a lower insulator 34, and a coil 33.

FIG. 2 is a plan view of the stator 30. FIG. Note that FIG. 2 illustrates a part of coil terminals 71a, 72a, 73a, 81a, 82a of the bus bar unit 60 described later.

The stator core 31 is composed of a plurality of core pieces 32 annularly arranged along the circumferential direction. In the stator core 31, the core pieces 32 adjacent in the circumferential direction are connected to each other. That is, the stator core 31 is configured by connecting a plurality of core pieces 32 along the circumferential direction.

The core piece 32 has a core back portion 32a, a teeth portion 32b, and an umbrella portion 32c. That is, the stator core 31 has a plurality of core back portions 32a, a plurality of teeth portions 32b, and a plurality of umbrella portions 32c. The stator core 31 of the present embodiment is composed of twelve core pieces 32. Therefore, the stator 30 of the present embodiment has twelve teeth portions 32 b. The number of core pieces 32 and teeth portions 32b is not limited to this.

The core back portion 32a extends along the circumferential direction. The core back portion 32 a is connected to the core back portion 32 a of the adjacent core piece 32 at an end portion facing in the circumferential direction. The core back portions 32a adjacent to each other in the circumferential direction are coupled by welding or the like. Thus, the core back portions 32a of all the core pieces 32 are annularly coupled.

Teeth portion 32 b extends radially inward from the circumferential center of core back portion 32 a. The coil 33 is wound around the teeth portion 32 b via the upper insulator 35 and the lower insulator 34.

The umbrella portion 32c is located at the tip (radially inner end) of the tooth portion 32b. The dimension along the circumferential direction of the umbrella portion 32c is larger than the dimension along the circumferential direction of the teeth portion 32b and smaller than the dimension along the circumferential direction of the core back portion 32a. The radially inner surface of the umbrella portion 32 c faces the rotor magnet 23 of the rotor 20.

Moreover, the stator core 31 of this embodiment is comprised from the several core piece 32 as what is called a division | segmentation core. However, the core piece constituting the stator core 31 may be a curling core in which the adjacent core back portions 32 a are partially connected to each other and bent in an annular shape after the winding of the coil 33.

As shown in FIG. 1, the upper insulator 35 covers at least the upper side of the teeth portion 32 b of the upper surface of the stator core 31. Similarly, the lower insulator 34 covers at least the lower side of the teeth portion 32 b of the lower surface of the stator core 31. That is, the upper insulator 35 covers the upper surface of the tooth portion 32b, and the lower insulator 34 covers the lower surface of the tooth portion 32b. The upper insulator 35 and the lower insulator 34 are made of an insulating material. The upper insulator 35 and the lower insulator 34 have the same configuration except that they are provided on the side opposite to the stator core 31 in the vertical direction.

As shown in FIG. 2, the upper insulator 35 has a plurality of insulator pieces 36 located on the upper side of the respective core pieces 32. Although not shown, the lower insulator 34 has a plurality of insulator pieces 36 in the same manner as the upper insulator 35.

The insulator pieces 36 of the upper insulator 35 are provided in the same number (12 in this embodiment) as the core pieces 32. One insulator piece 36 is disposed on the upper side of one core piece 32. The plurality of insulator pieces 36 are annularly arranged along the circumferential direction.

The insulator piece 36 has a base 36 b, a first standing wall 36 a and a second standing wall 36 c. The base portion 36 b is located on the upper side of the tooth portion 32 b and covers the upper surface of the tooth portion 32 b. The first upright wall portion 36 a protrudes upward from the radially outer end of the base portion 36 b and extends along the circumferential direction. The first upright wall portion 36a is located above the core back portion 32a. The second upright wall portion 36c protrudes upward from the radially inner end of the base 36b and extends along the circumferential direction. The second upright wall portion 36c is located on the upper side of the umbrella portion 32c.

The coil 33 is wound around the base 36 b. The first upright wall portion 36 a and the second upright wall portion 36 c are radially opposed to each other with the base portion 36 b interposed therebetween. The first upright wall 36 a and the second upright wall 36 c guide the coil 33 wound around the base 36 b from the radially outer side and the inner side, respectively.

The first upright wall portion 36a has a pair of end faces 36d facing both sides in the circumferential direction, and an outer peripheral surface 36e facing outward in the radial direction. The end faces 36 d of the adjacent insulator pieces 36 face each other in the circumferential direction. A chamfer 36f is provided between the first upright wall 36a and the outer peripheral surface 36e. Between the chamfers 36f of the adjacent insulator pieces 36, V-shaped leg housings 37 are provided as viewed from the axial direction. That is, the leg housing portion 37 is provided in the upper insulator 35.

Heretofore, there has been known a structure in which a recess provided on the outer peripheral surface of one insulator piece facing radially outward is a leg housing portion. On the other hand, according to the present embodiment, the leg housing portion 37 is provided by abutting the chamfers 36f of the pair of insulator pieces 36 arranged in the circumferential direction in the radial direction. For this reason, it is not necessary to provide a recessed part in one insulator piece 36, and when manufacturing the insulator piece 36 by injection molding, the freedom degree of the extraction direction of the insulator piece 36 can be raised. As a result, the insulator piece 36 can be manufactured inexpensively.

The leg accommodating portion 37 opens in one side in the radial direction (radially outer side in the present embodiment) when viewed from the axial direction, and has a V-shape which narrows in width toward the other side (radially inner side in the present embodiment). It is. The leg accommodating portion 37 is located above the boundary between adjacent core pieces 32 as viewed in the axial direction.

The leg portion 65 of the bus bar unit 60, which will be described later, is accommodated in the leg portion accommodating portion 37. The leg 65 fits in the V-shape of the leg accommodating portion 37. That is, the leg portion 65 has a V-shape which narrows in width toward the other side in the radial direction as viewed from the axial direction (in the radial direction in this embodiment).

The coil 33 is configured by winding a coil wire around the teeth portion 32 b via the upper insulator 35 and the lower insulator 34. Therefore, the plurality of coils 33 are annularly arranged along the circumferential direction.

In the present embodiment, the stator 30 is provided with twelve coils 33. The twelve coils 33 are wound in a continuous arc with a pair of coils 33 as one set. The two continuously wound coils 33 are connected via a connecting wire 33b. The crossover 33 b passes above the coil 33. The crossover wire 33 b is insulated from the coil 33 by an insulating tube (not shown).

One lead wire 33 a extends upward from each coil 33. The lead wire 33a corresponds to the winding start and the winding end of the two coils 33 wound in a continuous arc. Therefore, one lead wire 33 a extends from one coil 33. The lead wire 33a is connected to the coil terminals 71a, 72a, 73a, 81a, 82a described later. The coil terminals 71a, 72a, 73a, 81a, 82a are the coil terminals 71a, 72a, 73a of the phase bus bars 71, 72, 73, and the coil terminals 81a, 82a of the neutral point bus bars 81, 82, respectively. ,are categorized.

FIG. 3 is a schematic view showing wire connections of the coils 33 of the stator 30. As shown in FIG. Twelve coils 33 of stator 30 are four U-phase coils U1a, U1b, U2a, U2b, four V-phase coils V1a, V1b, V2a, V2b, and four W-phase coils W1a, W1b, W2a, W2b And consists of

FIG. 4 is a schematic view showing two systems of Y-connections formed by 12 coils 33. As shown in FIG. As shown in FIG. 4, the stator 30 has a U-phase coil, a V-phase coil and a W-phase coil as one system coil group, and a coil group (a first system) of a plurality of systems (two systems in this embodiment). The coil group 7 and the coil group 8 of the second system are included. That is, the stator 30 has two coil groups 7 and 8 classified into the first coil group 7 and the second coil group.

Coil group 7 of the first system has U-phase coils U1a and U1b, V-phase coils V1a and V1b, and W-phase coils W1a and W1b. The coil group 8 of the second system has U-phase coils U2a and U2b, V-phase coils V2a and V2b, and W-phase coils W2a and W2b. That is, two coils 33 are provided in one phase of each system. The two coils 33 of each phase of each system are connected by a connecting wire 33b. In other words, in each system, a plurality of U-phase coils, V-phase coils and W-phase coils are respectively provided, and are provided across the plurality of teeth portions 32 b via the crossover wires 33 b.

In coil group 7 of the first system, U-phase coils U1a and U1b, V-phase coils V1a and V1b, and W-phase coils W1a and W1b are connected to one another by Y connection. Similarly, in the coil group 8 of the second system, the U-phase coils U2a and U2b, the V-phase coils V2a and V2b, and the W-phase coils W2a and W2b are mutually connected by Y connection.

As shown in FIG. 3, one lead wire 33a of the two U-phase coils U1a and U1b of the first system connected via the crossover 33b is a U-phase bus bar 71A of the first system phase bus bar group 70A described later. And the other lead wire 33 a is connected to the first system neutral point bus bar 81.

Similarly, one lead wire 33a of the two V phase coils V1a and V1b of the first system linked via the crossover 33b is connected to the V phase bus bar 72A of the first system phase bus bar group 70A, and the other The lead wire 33 a is connected to the first system neutral point bus bar 81.

Further, one lead wire 33a of the two W-phase coils W1a and W1b of the first system connected via the crossover 33b is connected to the W-phase bus bar 73A of the first system phase bus bar group 70A, and the other The line 33 a is connected to the first system neutral point bus bar 81.

As described above, one ends of U-phase coils U1a and U1b, V-phase coils V1a and V1b, and W-phase coils W1a and W1b of the first system are connected to different phase bus bars 71, 72, 73, respectively. That is, the plurality of phase bus bars 71, 72, 73 are connected to the lead wires 33a drawn from the coils 33 of the respective phases. Further, the other ends of the U-phase coils U1a and U1b, the V-phase coils V1a and V1b, and the W-phase coils W1a and W1b of the first system are connected to the first system neutral point bus bar 81. That is, one first system neutral point bus bar 81 is connected to the lead wire 33 a drawn from the coil 33 of each phase. Thereby, the U-phase coils U1a and U1b of the first system, the V-phase coils V1a and V1b, and the W-phase coils W1a and W1b form a Y connection.

The wire connection configuration of the coils 33 of each phase of the coil group 8 of the second system is the same as the wire connection configuration of the coils of each phase of the coil group 7 of the first system. That is, the U-phase coils U2a and U2b of the second system are connected to the U-phase bus bar 71B and the second system neutral point bus bar 82 of the second system. The V-phase coils V2a and V2b of the second system are connected to the V-phase bus bar 72B and the second system neutral point bus bar 82 of the second system. The W-phase coils W2a and W2b of the second system are connected to the W-phase bus bar 73B of the second system and the second system neutral point bus bar 82. Thus, the U-phase coils U2a and U2b of the second system, the V-phase coils V2a and V2b, and the W-phase coils W2a and W2b form a Y connection.

According to this embodiment, the stator 30 has a plurality of coil groups (the first coil group 7 and the second coil group 8). Further, in the stator 30, the coil groups 7 and 8 of different systems are arranged symmetrically around the central axis J. Thereby, the redundancy of the motor 1 can be secured. That is, even when a failure occurs in any one of the plurality of coil groups 7 and 8, the motor 1 can be smoothly driven using the coil groups of other systems.

[Bus Bar Unit] The bus bar unit 60 is provided to the motor 1. The bus bar unit 60 is located between the stator 30 and the bearing holder 10 in the axial direction. That is, the bus bar unit 60 is provided above the stator 30 and below the bearing holder 10.

FIG. 5 is a perspective view of the bus bar unit 60. As shown in FIG. FIG. 6 is an exploded perspective view of the bus bar unit 60. As shown in FIG. FIG. 7 is a plan view of the bus bar unit 60. As shown in FIG.

The bus bar unit 60 includes a bus bar holder 61, a pair of terminal supports (external connection terminal supports) 66, a first system phase bus bar group 70A, a second system phase bus bar group 70B, and a first system neutral point bus bar 81 and a second system neutral point bus bar 82.

The first system phase bus bar group 70A and the first system neutral point bus bar 81 are connected to the first system coil group 7. Further, the second system phase bus bar group 70B and the second system neutral point bus bar 82 are connected to the second system coil group 8.

First system phase bus bar group 70A and second system phase bus bar group 70B are fixed to one axial direction side (upper side in the present embodiment) of bus bar holder 61, and first system neutral point bus bar 81 and second system The neutral point bus bar 82 is fixed to the other axial side (the lower side in this embodiment) of the bus bar holder 61. In the present specification, "one side" and "the other side" do not indicate a specific direction. That is, the above description can be rephrased as follows. The first system neutral point bus bar 81 and the second system neutral point bus bar 82 are fixed to one side of the bus bar holder 61 in the axial direction, and the first system phase bus bar group 70A and the second system phase bus bar group 70B are The bus bar holder 61 is fixed to the other side in the axial direction.

Further, the first system phase bus bar group 70A has a U phase bus bar 71A, a V phase bus bar 72A, and a W phase bus bar 73A. Similarly, the second system phase bus bar group 70B includes a U phase bus bar 71B, a V phase bus bar 72B, and a W phase bus bar 73B.

In the following description, when the U-phase bus bars 71A and 71B of different systems are not distinguished from one another, they are simply referred to as the U-phase bus bar 71. When the V- phase bus bars 72A and 72B of different systems are not distinguished from one another, they are simply referred to as the V-phase bus bars 72. When W- phase bus bars 73A and 73B of different systems are not distinguished from one another, they are simply referred to as W-phase bus bars 73. Furthermore, when the U-phase bus bar 71, the V-phase bus bar 72, and the W-phase bus bar 73 are not distinguished from one another, they are simply referred to as “phase bus bars 71, 72, 73”. Similarly, when the first system neutral point bus bar 81 and the second system neutral point bus bar 82 are not distinguished from one another, they are simply referred to as neutral point bus bars 81, 82.

U-phase bus bars 71A and 71B, V- phase bus bars 72A and 72B, and W- phase bus bars 73A and 73B are phase bus bars (first bus bars). That is, the plurality of phase bus bars 71, 72, 73 are U-phase coils U1a, U1b, U2a, U2b, V-phase coils V1a, V1b, respectively of coil group 7 of the first system and coil group 8 of the second system. A phase bus bar is connected to V2a, V2b and W-phase coils W1a, W1b, W2a, W2b, respectively.

(Bus Bar Holder) As shown in FIG. 1, the bus bar holder 61 is provided on the upper side of the stator 30. The bus bar holder 61 holds the phase bus bars 71, 72, 73 and the neutral point bus bars 81, 82. The bus bar holder 61 is made of a resin material.

As shown in FIG. 6, the bus bar holder 61 includes a holder main body (bus bar holder main body) 62, a pair of base portions 63, a plurality of (six in the present embodiment) clamping portions 64, and a plurality (this embodiment) And six legs 65).

The holder main body 62 has an annular shape centered on the central axis J when viewed in the axial direction. The holder main body portion 62 is located between the phase bus bars 71, 72, 73 and the neutral point bus bars 81, 82 in the axial direction. Further, the holder main body 62 has an upper surface 62 a facing upward and a lower surface 62 b facing downward. A plurality of phase bus bars 71, 72, 73 are disposed on the top surface 62 a of the holder body 62. A plurality of neutral point bus bars 81 and 82 are disposed on the lower surface 62 b of the holder main body 62.

As shown in FIG. 1, the lower surface 62b of the holder main body 62 is provided with a first wall 62c and a second wall 62d. That is, the bus bar holder 61 has a first wall 62 c and a second wall 62 d. The first wall 62 c and the second wall 62 d axially project from the lower surface 62 b. The first wall 62c and the second wall 62d extend in the circumferential direction, respectively. The first wall portion 62 c is located radially outward with respect to the neutral point bus bars 81 and 82. The second wall 62 d is located radially inward with respect to the neutral point bus bars 81 and 82. Therefore, neutral point bus bars 81, 82 are located between first wall 62c and second wall 62d in the radial direction and extend along the circumferential direction.

The lower surface 62b of the holder main body 62 is provided with a plurality of shaft portions 67a, 68a, 69a and a plurality of welded portions 67b, 68b, 69b located at the tip of each of the shaft portions 67a, 68a, 69a. That is, the bus bar holder 61 has a plurality of shaft portions 67a, 68a, 69a and a plurality of welding portions 67b, 68b, 69b. As will be described later with reference to FIG. 10, the plurality of welds 67 b, 68 b, 69 b fix the neutral point bus bars 81, 82 to the bus bar holder 61.

As shown in FIG. 6, the base portion 63 protrudes upward from the upper surface 62 a of the holder main body portion 62. The pair of base portions 63 is located on the opposite side across the central axis J. Of the pair of base portions 63, one holds the external connection terminals 71c, 72c, 73c of the first system phase bus bar group 70A, and the other holds the external connection terminals 71c, 72c of the second system phase busbar group 70B. , 73c hold.

The base portion 63 has an upper surface 63a facing upward. The terminal support 66 is mounted on the upper surface 63 a of the base portion 63. The upper surface 63a is provided with four recessed grooves (concave portions) 63d. That is, the recessed portion 63 d is provided in the bus bar holder 61. In the four recessed grooves 63d, a part of the V-phase bus bar 72, a part of the W-phase bus bar 73, and two U-phase bus bars 71 of different systems (the first U-phase bus bars 71A and the second system A part of U-phase bus bar 71B of the system is inserted. Thus, the base portion 63 holds the plurality of phase bus bars 71, 72, 73.

As shown in FIG. 1, the upper surface 63a of the base portion 63 is provided with a shaft portion 63b extending upward and a welded portion 63c located at the upper end of the shaft portion 63b. That is, the bus bar holder 61 has the shaft portion 63 b and the welded portion 63 c.

The shaft portion 63 b passes through a fixing hole 66 h provided in the terminal support 66. The welding portion 63c extends to the outside of the fixing hole 66h on the upper side of the fixing hole 66h of the terminal support 66 as viewed from the axial direction. The welding part 63c is hemispherical shape which becomes convex upward. The welding portion 63c is formed by melting the upper end portion of the shaft portion 63b by heat. Welded portion 63c prevents terminal support 66 from coming off shaft portion 63b. The terminal support 66 is fixed to the bus bar holder 61 by providing the welding portion 63 c.

As shown in FIG. 7, the sandwiching portion 64 is provided on the upper surface 62 a of the holder main body 62. The holding portion 64 has a pair of claw portions 64a extending upward from the upper surface 62a. The pair of claws 64 a sandwich and hold the phase bus bars 71, 72, 73 in the thickness direction. That is, the sandwiching portion 64 holds the plurality of phase bus bars 71, 72, 73 in the thickness direction. In the present embodiment, the holding portions 64 are provided in the same number (six) as the phase bus bars 71, 72, 73 provided on the upper side of the bus bar holder 61. Therefore, one phase bus bar 71, 72, 73 is held by one holding portion 64. Note that the number of the holding parts 64 may be more than six.

A plurality of (six in the present embodiment) legs 65 are provided on the bus bar holder 61. The plurality of legs 65 are arranged at equal intervals around the central axis. The bus bar holder 61 is supported by the stator 30 at the leg portion 65.

As shown in FIG. 6, the leg portion 65 is a radially extending portion 65a extending radially outward from the outer edge of the holder main body 62, and a lower side extending downwardly from the radially outer end of the radially extending portion 65a. And an extending portion 65b. That is, the legs 65 extend downward with respect to the holder body 62.

As shown in FIG. 9, the lower end portion 65c of the leg portion 65 has a V shape which narrows inward as it goes radially inward as viewed from the axial direction. As shown in FIG. 2, the V-shaped lower end 65 c is accommodated in a leg accommodating portion 37 provided in the upper insulator 35. Further, the leg portion 65 contacts the upper surface of the stator 30 at the lower end surface. As described above, the leg accommodating portion 37 has a V-like shape similar to or similar to that of the lower end portion 65 c of the leg 65 when viewed in the axial direction. The leg portion 65 is accommodated in the leg portion accommodating portion 37, whereby the bus bar holder 61 is positioned with respect to the stator 30 in a plane perpendicular to the axial direction.

The leg accommodating portion 37 is provided on the upper side of the boundary between the core pieces 32 adjacent in the circumferential direction. The leg 65 accommodated in the leg accommodating portion 37 is provided on the upper side of the boundary between the core pieces 32 adjacent in the circumferential direction. That is, the leg portion 65 is disposed overlapping the boundary between the core pieces 32 adjacent in the circumferential direction when viewed from the axial direction.

According to the present embodiment, the lower end portion 65 c of the leg portion 65 and the leg portion accommodation portion 37 have a V shape that narrows toward the one radial direction side, whereby the leg portion 65 with respect to the leg portion accommodation portion 37 Insertion is easy. In addition, each leg 65 contacts the V-shaped wall when viewed from the axial direction facing one side and the other side of the leg accommodating portion 37 in the circumferential direction. Therefore, the positioning accuracy of the bus bar holder 61 in the circumferential direction can be enhanced. The leg housing portion 37 may have a shape other than the V shape. For example, even if it is trapezoidal shape and semicircular arc shape, the same effect can be acquired.

As shown in FIG. 2, when viewed from the axial direction, a straight line connecting the lead axis 33 a drawn from each of the coils 33 and the central axis J is an imaginary line VL. When viewed from the axial direction, the leg portion 65 is located between the imaginary lines VL of the lead lines 33 a of the pair of coils 33 adjacent in the circumferential direction. The lead wire 33a is any one of coil terminals 71a, 72a, 73a, 81a, 82a provided on the plurality of phase bus bars 71, 72, 73 and the plurality of neutral point bus bars 81, 82, respectively. Connected to

According to the present embodiment, the leg portion 65 is disposed between the pair of virtual lines VL aligned in the circumferential direction, whereby the leg portion 65 and the coil terminal 71a, 72a, 73a, 81a, in the circumferential direction It can be arranged offset with 82a. Thus, interference between the leg portion 65 and the coil terminals 71a, 72a, 73a, 81a, 82a and the lead wire 33a can be suppressed. In addition, the leg portion 65 does not easily inhibit the welding process of the coil terminals 71a, 72a, 73a, 81a, 82a and the lead wire 33a.

In the present embodiment, the plurality of coil terminals 71a, 72a, 73a, 81a and 82a are alternately arranged at a first interval and a second interval narrower than the first interval along the circumferential direction. Therefore, the plurality of virtual lines VL radially extending from the central axis J alternately extend at a first angle α and a second angle β smaller than the first angle α along the circumferential direction. The leg portion 65 of the present embodiment is located between a pair of virtual lines VL forming the first angle α. The leg 65 is disposed between the pair of virtual lines VL forming the first angle α and between the pair of virtual lines VL forming the second angle β. A certain effect of suppressing the interference between the portion 65 and the lead wire 33a can be obtained. Further, as shown in the present embodiment, by arranging the leg portion 65 between the pair of virtual lines VL forming the first angle α, the effect of suppressing the interference between the leg portion 65 and the lead wire 33a Can be further enhanced.

Further, when viewed from the axial direction, the leg portion 65 is between the pair of coil terminals (for example, the pair of coil terminals 81a and 73a) connected to the lead wires 33a of the pair of coils 33 adjacent in the circumferential direction. To position. According to the present embodiment, even when the radial positions of the leg portion 65 and the coil terminals 81a and 73a coincide with each other, the leg portion 65 and the coil terminals 81a and 73a are offset in the circumferential direction. Therefore, interference between the leg portion 65 and the coil terminals 81a and 73a can be suppressed.

Further, according to the present embodiment, the above-described arrangement suppresses the interference between the leg 65 and the coil terminals 71a, 72a, 73a, 81a, 82a, so the leg 65 and the coil terminals 71a, 72a, There is no need to shift the positions 73a, 81a and 82a in the axial direction. More specifically, as shown in FIG. 5, a part of the leg portion 65 can be arranged so as to axially overlap with a part of the coil terminal 82a. The axial dimension of the bus bar unit 60 can be reduced by arranging at least a part of the leg portion 65 so as to axially overlap the coil terminal 82a.

(Phase bus bar (first bus bar, bus bar))
The plurality of phase bus bars 71, 72, 73 are fixed to the upper side of the bus bar holder 61. The plurality of phase bus bars 71, 72, 73 are classified into a first system phase bus bar group 70A and a second system phase bus bar group 70B. As described above, the first system phase bus bar group 70A and the second system phase bus bar group 70B respectively have the U phase bus bar 71, the V phase bus bar 72, and the W phase bus bar 73.

The U-phase bus bars 71 of the first system phase bus bar group 70A and the second system phase bus bar group 70B have the same shape, and the first system phase bus bar group 70A and the second system phase bus bar group 70B The V-phase bus bars 72 have the same shape, and the W-phase bus bars 73 of the first system phase bus bar group 70A and the second system phase bus bar group 70B have the same shape.

As shown in FIG. 6, the U-phase bus bar 71 includes a bus bar main body 71b, a coil terminal 71a, an external connection terminal 71c, and a protrusion 71e. Similarly, the V-phase bus bar 72 includes a bus bar main body 72b, a coil terminal 72a, an external connection terminal 72c, and a protrusion 72e. Furthermore, the W-phase bus bar 73 includes a bus bar main body portion 73b, a coil terminal 73a, an external connection terminal 73c, and a protruding portion 73e.

The bus bar main body portions 71b, 72b, 73b extend along a plane orthogonal to the axial direction. The bus bar main body portions 71b, 72b, 73b extend along the circumferential direction, respectively. The bus bar main body portions 71b, 72b and 73b are arranged with the direction orthogonal to the axial direction as the thickness direction.

Coil terminals 71a, 72a, 73a are located at one end of bus bar main body portions 71b, 72b, 73b, respectively. The coil terminals 71a, 72a, 73a extend radially outward from the bus bar main body portions 71b, 72b, 73b. The coil terminals 71a, 72a, 73a may extend radially inward with respect to the bus bar main portions 71b, 72b, 73b. That is, coil terminals 71a, 72a, 73a may extend to one side in the radial direction with respect to bus bar main portions 71b, 72b, 73b.

The coil terminals 71a, 72a, 73a are connected to the lead 33a. The coil terminals 71a, 72a, 73a are portions for gripping the lead 33a. The shape in plan view of the coil terminals 71a, 72a, 73a is a substantially U shape opened inward in the radial direction. The coil terminals 71a, 72a, 73a are disposed with the direction orthogonal to the axial direction as the thickness direction.

The external connection terminals 71c, 72c, 73c are located at the ends (other ends) of the busbar main body portions 71b, 72b, 73b opposite to the coil terminals 71a, 72a, 73a, respectively. The external connection terminals 71c, 72c, 73c extend upward from the bus bar main body portions 71b, 72b, 73b.

The three external connection terminals 71c, 72c, 73c are provided in the first system phase bus bar group 70A and the second system phase bus bar group 70B, respectively. The external connection terminals 71c, 72c and 73c of the first system phase bus bar group 70A and the external connection terminals 71c, 72c and 73c of the second system phase busbar group 70B are arranged on the opposite side across the central axis J. .

The external connection terminals 71c, 72c, 73c are arranged with the direction orthogonal to the axial direction as the thickness direction. Further, the external connection terminals 71c of the U-phase bus bar 71 are disposed with the direction orthogonal to the radial direction as the sheet width direction. On the other hand, external connection terminals 72c and 73c of V-phase bus bar 72 and W-phase bus bar 73 are arranged with the direction orthogonal to the board width direction of external connection terminals 71c of U-phase bus bar 71 as the board width direction.

As shown in FIG. 6, the protrusions 71e, 72e and 73e extend from the connection between the busbars 71b, 72b and 73b and the external connection terminals 71c, 72c and 73c to the opposite side of the busbars 71b. The protrusions 71e, 72e, 73e are disposed with the direction orthogonal to the axial direction as the thickness direction.

The phase bus bars 71, 72, 73 are connection portions between the bus bar main portions 71b, 72b, 73b and the external connection terminals 71c, 72c, 73c and recessed grooves provided in the bus bar holder 61 at the protruding portions 71e, 72e, 73e. Recessed portion) 63d. Therefore, the phase bus bars 71, 72, 73 are held by the bus bar holder 61 at the roots of the external connection terminals 71c, 72c, 73c. Therefore, the stress received when inserting the external connection terminals 71c, 72c, 73c into the socket of the external device can be stably supported by the bus bar holder 61.

Further, according to the present embodiment, the bus bar main body portions 71b, 72b, 73b and the projecting portions 71e, 72e, 73e are plates of the external connection terminals 71c, 72c, 73c at the roots of the external connection terminals 71c, 72c, 73c. It extends on both sides in the width direction. The bus bar main portions 71b, 72b, 73b and the protrusions 71e, 72e, 73e suppress rattling of the external connection terminals 71c, 72c, 73c in the plate width direction inside the recessed groove 63d. Thereby, the stability of insertion of the external connection terminals 71c, 72c, 73c into the socket of the external device can be enhanced.

In the phase bus bars 71, 72, 73, the entire widths of the bus bar main portions 71b, 72b, 73b and the entire widths of the protruding portions 71e, 72e, 73e overlap in the axial direction. For this reason, the stability of the external connection terminals 71c, 72c, 73c can be enhanced in the effect of suppressing rattling on both sides in the width direction of the external connection terminals 71c, 72c, 73c.

As shown in FIG. 7, the U-phase bus bar 71 is the phase bus bar having the largest length along the circumferential direction of the bus bar main body portion among the three types of phase bus bars 71, 72, 73. The bus bar main portion 71b of the U-phase bus bar 71 is located radially inward of the bus bar main portions 72b and 73b of the other phase bus bars (V-phase bus bar 72 and W-phase bus bar 73). More specifically, bus bar main portion 71b of U-phase bus bar 71 is positioned radially inward of W-phase bus bar 73 belonging to V-phase bus bar 72 belonging to the same system bus bar group and another system bus bar group Do.

The phase bus bars 71, 72, 73 of the present embodiment are arranged to overlap in the radial direction in the bus bar main body portions 71b, 72b, 73b. Therefore, the phase bus bars 71, 72, 73 can be compactly arranged in the radial direction by arranging the thickness directions of the bus bar main portions 71b, 72b, 73b to be orthogonal to the axial direction. As a result, the radial dimension of the bus bar unit 60 can be reduced.

According to the present embodiment, among the plurality of phase bus bars 71, 72, 73, the U-phase bus bar 71 having the largest length along the circumferential direction of the bus bar main body portion 71b is the other phase bus bar (that is, V). It radially overlaps at least a part of the phase bus bar 72 and the W phase bus bar 73). Further, the bus bar main portion 71b of the U-phase bus bar 71 is located on the opposite side to the direction in which the coil terminals 72a and 73a of the other phase bus bars extend in the radial direction. Therefore, the bus bar main portion 71b of the U-phase bus bar 71 has a sufficient radial distance from the lead 33a connected to the V-phase bus bar 72 and the coil terminals 72a and 73a of the W-phase bus bar 73. It can be placed apart. As a result, insulation can be ensured without separating the bus bar main body 71b of the U-phase bus bar 71 and the lead wire 33a by a wall or the like.

In the present embodiment, the V-phase bus bar 72 and the W-phase bus bar 73 are held by the sandwiching portion 64 in the region extending in the radial direction of the coil terminals 72 a and 73 a. On the other hand, U-phase bus bar 71 is held by sandwiching portion 64 in bus bar main body portion 71 b. The holding portion 64 holding the U-phase bus bar 71 does not overlap in the radial direction with the V-phase bus bar 72 and the W-phase bus bar 73 in the radial direction. That is, among the plurality of phase bus bars 71, 72, 73, the U-phase bus bar 71 having the longest length along the circumferential direction of the bus bar main body portion 71b is a region not overlapping in a radial direction with other phase bus bars. The bus bar main body portion 71 b is held by the holding portion 64. In other words, the bus bar main portion 71 b of the U-phase bus bar 71 radially overlaps the V-phase bus bar 72 and the W-phase bus bar 73 in a region not held by the sandwiching portion 64. Therefore, the U-phase bus bar 71, the V-phase bus bar 72, and the W-phase bus bar 73 can be disposed close to each other in the radial direction.

The bus bar main portion 71 b of the U-phase bus bar 71 extends 180 ° around the central axis J along the circumferential direction. Therefore, the external connection terminal 71c located at one end of the bus bar main body 71b and the coil terminal 71a located at the other end of the bus bar main body 71b are disposed on the opposite side across the central axis J. Thereby, the external connection terminals 71c, 72c, 73c of one system are reduced while the dimensions along the circumferential direction of the main body portions 72b, 73b of the other phase bus bars (V phase bus bar 72 and W phase bus bar 73) are reduced. Can be arranged side by side. In the present embodiment, among the plurality of phase bus bars 71, 72, 73, the case where the phase bus bar having the largest length along the circumferential direction of the bus bar main body is the U-phase bus bar 71 has been described. However, when the bus bar main portions 72b and 73b of the V phase bus bar 72 or the W phase bus bar 73 are longer than the bus bar main portions of other phase bus bars, the bus bar main portions 72b of these phase bus bars 72 and 73 , 73 b may extend 180 ° around the central axis J.

In the present embodiment, the external connection terminals 71c, 72c, 73c of the different phase busbars 71, 72, 73 of different phases and located on the opposite side with respect to the central axis J. That is, the external connection terminals 71c, 72c, 73c of the pair of phase bus bars 71, 72, 73 connected to the coils 33 of the same phase of the coil group 7 of the first system and the coil group 8 of the second system It is disposed on the opposite side across the axis J. Thereby, the three external connection terminals 71c, 72c, 73c of the first system and the second system can be arranged symmetrically with respect to the central axis J. As a result, even if the circumferential position of the motor 1 is rotated by 180 °, the motor 1 can be connected to the external device, and the process of connecting the motor 1 to the external device can be simplified.

When viewed from the axial direction, one external connection terminal 71c of the first U-phase bus bar 71A and the second U-phase bus bar 71B and the other coil terminal 71a are partially viewed in the axial direction. Overlap. The bus bar main portion 71b of the U-phase bus bar 71A has a crank portion 71d extending in the axial direction in the vicinity of the root of the external connection terminal 71c. By providing the crank portion 71d in the bus bar main body portion 71b, the external connection terminal 71c is offset upward, and interference with the coil terminal 71a is suppressed.

As shown in FIG. 6, the bus bar main portions 72 b and 73 b of the V-phase bus bar 72 and the W-phase bus bar 73 do not have a portion corresponding to the crank portion 71 d of the U-phase bus bar 71. Therefore, the bus bars 72 b and 73 b of the V-phase bus bar 72 and the W-phase bus bar 73 extend only in a plane orthogonal to the axial direction.

In the phase bus bars 71, 72, 73, the bus bar main portions 71b, 72b, 73b and the coil terminals 71a, 72a, 73a are formed by bending a plate material extending in one direction. Further, in the V-phase bus bar 72 and the W-phase bus bar 73, the full width of the bus bar main portions 72b and 73b and the full width of the coil terminals 72a and 73a overlap in the axial direction. Therefore, when the V-phase bus bar 72 and the W-phase bus bar 73 are manufactured by press working, the V-phase from the plate material is compared with the case where the coil terminal extends upward or downward with respect to the bus bar main body. It is possible to increase the number of removed bus bars 72 and W-phase bus bars 73.

(Terminal support (External connection terminal support))
Terminal support 66 is fixed to the upper side of bus bar holder 61. The terminal support 66 covers the upper surface 63 a of the base portion 63 of the bus bar holder 61. The terminal support 66 is made of a resin material.

The terminal support 66 has a terminal support main body 66a, three support portions 66b extending in a columnar shape on the upper side from the terminal support main body 66a, and a convex portion 66d projecting downward from the terminal support main body 66a. The support portion 66b has a cylindrical shape. The three support portions 66b are arranged along the circumferential direction.

As shown in FIG. 1, the terminal support body 66 a is provided with a fixing hole 66 h penetrating in the axial direction. The shaft portion 63 b of the bus bar holder 61 is inserted into the fixing hole 66 h.

Each of the three support portions 66b is provided with a holding hole 66c penetrating in the axial direction. That is, the terminal support 66 is provided with three holding holes 66c. The external connection terminals 71c, 72c, and 73c of the U-phase bus bar 71, the V-phase bus bar 72, and the W-phase bus bar 73 are respectively inserted into the three holding holes 66c. Thereby, the three holding holes 66c hold the external connection terminals 71c, 72c, 73c.

The external connection terminals 71c, 72c, 73c are inserted from the lower side of the holding hole 66c, and project above the support portion 66b. The external connection terminals 71c, 72c, 73c pass through the through holes 16a of the bearing holder 10 in a region surrounded by the support portion 66b.

According to this embodiment, the external connection terminals 71 c, 72 c, 73 c are held by the holding holes 66 c of the terminal support 66. As a result, the stability of the external connection terminals 71c, 72c, 73c when inserted into the socket of the external device can be enhanced.

According to the present embodiment, the external connection terminals 71 c, 72 c and 73 c are surrounded by the support portion 66 b of the terminal support 66. Therefore, when the bus bar unit 60 is disposed below the bearing holder 10 and the external connection terminals 71c, 72c and 73c are inserted into the through holes 16a of the bearing holder 10, the external connection terminals 71c, 72c and 73c and the through holes 16a The support portion 66b can be interposed between the inner peripheral surface of As a result, the insulation between the external connection terminals 71c, 72c, 73c and the bearing holder 10 can be secured.

As shown in FIG. 6, the convex part 66d extends in a plate shape downward from the terminal support main body 66a. The convex portion 66 d fits in the concave groove 63 d of the bus bar holder 61. Thereby, the reliability of holding of the terminal support 66 by the bus bar holder 61 can be enhanced. As a result, it is possible to enhance the certainty of the holding of the external connection terminals 71c, 72c, 73c held by the terminal support 66.

As described above, in the concave groove 63d, the bus bar main body portions 71b, 72b, 73b of the phase bus bars 71, 72, 73 are inserted. The convex portion 66d is fitted into the concave groove 63d from the upper side of the bus bar main body portions 71b, 72b, 73b. Thus, the phase bus bars 71, 72, 73 can be pressed from the upper side in the recessed groove 63d, and the holding of the phase bus bars 71, 72, 73 in the bus bar unit 60 can be stabilized.

Of the three projections 66d, the two projections 66d for pressing the bus bars 72b and 73b of the V-phase bus bar 72 and the W-phase bus bar 73 from the upper side are respectively located on the lower side along the external connection terminals 72c and 73c. It extends and fits in the concave groove 63d. Therefore, these two convex portions 66 d can press the vicinity of the roots of the external connection terminals 72 c and 73 c from the upper side, and the effect of stabilizing the external connection terminals 72 c and 73 c is enhanced.

FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. The fixing structure of the V-phase bus bar 72 inserted into the recessed groove 63d will be described with reference to FIG. Although the description is omitted here, the same fixing structure is adopted for the U-phase bus bar 71 and the W-phase bus bar 73 which are inserted into the other recessed grooves 63 d.

The upper opening of the recessed groove 63d is provided with a tapered portion 63e whose groove width becomes wider toward the upper side. By providing the tapered portion 63e, the process of inserting the phase bus bar 72 and the convex portion 66d into the concave groove 63d is facilitated.

The tip end face 66 f of the convex part 66 d contacts the face of the phase bus bar 72 facing upward. A welding portion 66e joined to the inner surface of the concave groove 63d is provided at the tip of the convex portion 66d. The welded portion 66e is formed by melting and solidifying the tip of the convex portion 66d. The welded portion 66e is joined to the wall surface of the recessed groove 63d and the bus bar 72 for phase in the process of solidification. Thus, the terminal support 66 can be firmly fixed to the bus bar holder 61. In addition, removal of the phase bus bar 72 from the recessed groove 63 d can be effectively suppressed. In the present embodiment, the welding portion 66e is provided at the tip of the convex portion 66d. However, it is preferable that the welded portion 66e is provided at least at a part of the convex portion 66d.

The terminal support 66 is made of a resin material including a first resin portion 66A and a second resin portion 66B which are integrally formed. That is, the terminal support 66 is molded by two-color molding. That is, the terminal support 66 is molded by two-color molding of the first resin portion 66A and the second resin portion 66B.

The second resin portion 66B is a thermoplastic resin material having a melting point lower than that of the first resin portion 66A. The terminal support main body 66a and the support 66b are formed of a first resin portion 66A. On the other hand, the convex part 66d is comprised from the 2nd resin part 66B.

According to the present embodiment, the welded portion 66e is configured of the second resin portion 66B having a low melting point. Therefore, the welded portion 66e can be easily formed by heating the terminal support 66 in a state where the convex portion 66d is inserted into the concave groove 63d. In the present embodiment, the case where the entire convex portion 66d is formed of the second resin portion 66B is illustrated. However, a part of the portion fitted to the concave groove 63d of the convex portion 66d may be configured by the second resin portion 66B.

A procedure for fixing the terminal support 66 to the bus bar holder 61 in the method of manufacturing the bus bar unit 60 will be described. First, the bus bar attaching step of attaching the phase bus bars 71, 72, 73 to the bus bar holder 61 is performed. In the phase bus bar attaching step, the phase bus bars 71, 72, 73 are inserted into the recessed grooves 63d provided in the bus bar holder 61.

Next, a terminal support attachment step (external connection terminal support attachment step) for attaching the terminal support 66 to the bus bar holder 61 is performed. In the terminal support attachment step, first, the external connection terminals 71c, 72c, 73c are inserted into the holding holes 66c of the terminal support 66. Then, the convex portion 66 d of the terminal support 66 is fitted into the concave groove 63 d from the upper side of the phase bus bars 71, 72, 73. Further, heat is applied to the terminal support 66 to melt and solidify a part of the convex portion 66d, thereby forming a welded portion 66e joined to the inner surface of the concave groove 63d.

In the procedure of forming the welded portion 66e, a current may be supplied to the phase bus bars 71, 72, 73 to melt a part of the convex portion 66d. By supplying current to the phase bus bars 71, 72, 73, the phase bus bars 71, 72, 73 generate heat due to Joule heat. The heat is transmitted to the convex portion 66 d to melt a part of the convex portion 66 d. In the case where the welded portion 66e is formed by supplying current to the phase bus bars 71, 72, 73, only the tip end portion of the convex portion 66d can be locally heated. Therefore, the welded portion 66e can be formed without affecting other portions of the terminal support 66. It should be noted that when forming the welded portion 66e by Joule heat, the current value supplied to the phase bus bars 71, 72, 73 is sufficiently larger than the current value when the motor 1 is driven.

(Neutral point bus bar (second bus bar, bus bar))
As described above, the stator 30 of the present embodiment has the two coil groups 7 and 8 (see FIG. 4). The plurality of neutral point bus bars 81 and 82 are provided in the same number as the number of coil groups (i.e., the number of systems). Therefore, the bus bar unit 60 of the present embodiment has two neutral point bus bars 81 and 82.

FIG. 9 is a bottom view of the bus bar unit 60. As shown in FIG. As shown in FIG. 9, the neutral point bus bars 81 and 82 have bus bar main body portions 81 b and 82 b and three coil terminals 81 a and 82 a. Neutral point bus bars 81 and 82 are plate-like. In neutral point bus bars 81 and 82, at least bus bar main body portions 81b and 82b are arranged with the axial direction as the thickness direction.

The bus bar main body portions 81 b and 82 b extend along a plane orthogonal to the axial direction. The bus bar main body portions 81 b and 82 b extend in the circumferential direction in the region of 240 ° around the central axis J, respectively. At least a portion of the bus bar main body portions 81 b and 82 b is exposed from the bus bar holder 61. That is, neutral point bus bars 81 and 82 are not resin-inserted in bus bar holder 61.

The coil terminals 81a and 82a are connected to the lead 33a. The coil terminals 81a and 82a include a portion for gripping the lead 33a. The plan view shape of the coil terminals 81a and 82a is a substantially U shape opened inward in the radial direction. The coil terminals 81a and 82a are disposed with the direction orthogonal to the axial direction as the thickness direction.

The three coil terminals 81a and 82a are arranged at equal intervals along the longitudinal direction (that is, the circumferential direction) of the bus bar main portions 81b and 82b. Of the three coil terminals 81a and 82a, two coil terminals 81a and 82a are located at both ends of the bus bar main portions 81b and 82b, and the remaining one coil terminal 81a and 82a is the two coil terminals described above. Located between 81a and 82a.

The coil terminals 81a and 82a extend in the radial direction away from the bus bar main portions 81b and 82b. More specifically, the coil terminals 81a and 82a extend radially outward from the bus bar main portions 81b and 82b.

The coil terminals 81a and 82a may extend inward in the radial direction with respect to the bus bar main portions 81b and 82b. That is, the coil terminals 81a and 82a may extend to one side in the radial direction with respect to the bus bar main portions 81b and 82b.

The coil terminals 81a and 82a of the neutral point bus bars 81 and 82 and the coil terminals 71a, 72a and 73a of the phase bus bars 71, 72 and 73 are connected to the bus bar main portions 81b, 82b, 71b, 72b and 73b, respectively. It extends in the same radial direction. By arranging in this manner, with respect to the bus bar holder 61, the neutral point bus bars 81, 82 and the coil terminals 81a, 82a, 71a, 72a, 73a of the phase bus bars 71, 72, 73 project in the radial direction. You can align the direction. Therefore, the radial positions of the lead wires 33a which extend from the stator 30 and are connected to the coil terminals 81a, 82a, 71a, 72a, 73a can be aligned. Thereby, it is hard to complicate the structure (the 1st wall 62c etc. in this embodiment) which insulates neutral point bus bars 81 and 82 and phase bus bars 71, 72 and 73 of bus bar holder 61, and leader 33a. . Further, by arranging in this manner, the coil terminals 71a, 72a, 73a of the plurality of phase bus bars 71, 72, 73 and the coil terminals 81a of the plurality of neutral point bus bars 81, 82 when viewed from the axial direction. , 82a align in a single virtual circle VC around the central axis J. For this reason, by rotating the bus bar unit 60 and the stator 30 around the central axis J in the welding process, the lead wire 33a and the coil terminals 81a, 82a, 71a, 72a, are not moved in the radial direction without moving the welding jig. 73a can be welded and connected. This can simplify the welding process.

The coil terminals 81a and 82a extend downward from the bus bar main portions 81b and 82b. That is, coil terminals 81a, 82a extend in the direction away from phase bus bars 71, 72, 73 in the axial direction. As a result, the coil terminals 81a and 82a can be axially separated from the coil terminals 71a, 72a and 73a of the phase bus bars 71, 72 and 73, and mutual interference can be suppressed. In addition, in the process of welding the lead wire 33a to one of the neutral point bus bars 81 and 82 and the phase bus bars 71, 72 and 73, the other coil terminal deteriorates the welding workability. Can be suppressed.

The plurality of neutral point bus bars 81 and 82 are classified into a first system neutral point bus bar 81 and a second system neutral point bus bar 82. The first system neutral point bus bar 81 is connected to the lead wire 33 a of the coil 33 of each phase (U phase, V phase, W phase) of one system coil group (the first system coil group 7). Similarly, the second system neutral point bus bar 82 is connected to the lead 33a of the coil 33 of each phase (U phase, V phase, W phase) of one system coil group (second system coil group 8) Be done. The coil terminals 71a, 72a, 73a of the phase bus bars 71, 72, 73 and the coil terminals 81a, 82a of the neutral point bus bars 81, 82 are alternately arranged in the circumferential direction.

As shown in FIG. 6, the plurality of neutral point bus bars 81 and 82 are fixed to the lower side of the bus bar holder 61. The plurality of neutral point bus bars 81, 82 at least partially overlap each other when viewed in the axial direction.

The plurality of neutral point bus bars 81 and 82 are plate members in which at least the bus bar main body portions 81 b and 82 b are arranged with the axial direction as the thickness direction. That is, the neutral point bus bars 81 and 82 of the present embodiment are so-called flat type. For this reason, even when the plurality of neutral point bus bars 81 and 82 are arranged in an axial direction, the axial dimension is unlikely to be large.

According to the present embodiment, of the phase bus bars 71, 72, 73 and the neutral point bus bars 81, 82, the neutral point bus bars 81, 82 are flat type. On the other hand, the phase bus bars 71, 72, 73 are so-called vertical type, in which the bus bar main portions 71b, 72b, 73b are arranged with the axial direction as the thickness direction. Generally, at least three phase bus bars 71, 72, 73 are required to correspond to the U-phase, V-phase, and W-phase coils 33, respectively. Therefore, in the case where the phase bus bars 71, 72, 73 are placed flat and stacked in the axial direction, three or more layers are required to be stacked corresponding to the bus bars of the respective phases. In addition, insulating layers are provided between the stacked bus bars. For this reason, in the case where a stacked arrangement of three or more layers is required, the axial dimension is the sum of the plate thicknesses of the three bus bars and the thickness of the insulating layer between them, and by overlapping and arranging The effect of axial miniaturization is diminished. According to the present embodiment, by stacking the two neutral point bus bars 81 and 82 as flat type, the effect of axial dimension suppression can be enhanced. The insulating layer provided between the bus bars superimposed in the axial direction described above is an air layer in the present embodiment.

As shown in FIG. 9, the plurality of neutral point bus bars 81, 82 are disposed between the first wall 62c and the second wall 62d provided in the holder main body 62, and are circumferentially It extends along. The first wall portion 62c and the second wall portion 62d are disposed with the bus bar main portions 81b and 82b of the neutral point bus bars 81 and 82 interposed therebetween in the radial direction.

According to the present embodiment, the first wall 62 c is located between the bus bar main portions 81 b and 82 b of the neutral point bus bars 81 and 82 and the lead wires 33 a when viewed from the axial direction. Thereby, neutral point bus bars 81 and 82 and lead wires 33a can be easily insulated.

According to the present embodiment, the neutral point bus bars 81 and 82 are sandwiched between the first wall 62 c and the second wall 62 d from inside and outside in the radial direction. Therefore, neutral point bus bars 81 and 82 can be easily positioned in the radial direction.

According to the present embodiment, by providing the first wall 62 c and the second wall 62 d in the holder body 62, the rigidity of the holder body 62 can be enhanced.

The first wall 62c is provided with a first notch 62ca and a second notch 62cb. Further, only the second notch 62db is provided in the second wall 62d. The neutral point bus bars 81 and 82 are exposed in the radial direction in the first notch 62 ca or the second notch 62 cb and 62 db.

The coil terminals 81a and 82a of the neutral point bus bars 81 and 82 pass through the first cutouts 62ca. By providing the first notches 62ca, it is possible to adopt a structure in which the coil terminals 81a and 82a are extended directly outward in the radial direction from the bus bar main portions 81b and 82b. That is, it is not necessary to provide the coil terminals 81a and 82a with a portion extending downward and over the first wall 62c, and the neutral point bus bars 81 and 82 can be manufactured at low cost.

The second notches 62cb and 62db radially overlap the wide portions 81s and 82s of the neutral point bus bars 81 and 82 described later. By providing the second notches 62 cb and 62 db, interference of the wide portions 81 s and 82 s with the bus bar holder 61 can be suppressed.

In the present embodiment, a part of the second notches 62cb allows the coil terminal 81a to pass through. That is, some of the second notches 62cb also function as notches that allow the coil terminals 81a to pass through.

Of the plurality of second cutouts 62cb provided in the first wall 62c, at least a portion of the second cutouts 62cb are arranged to be offset from the lead 33a in the radial direction. By arranging the second notches 62cb to be offset from the lead wires 33a in the radial direction, it is easy to ensure insulation between the bus bar main portions 81b and 82b exposed from the second notches 62cb and the leads 33a. In addition, all the 2nd notch parts 62cb may be shifted | deviated from the lead wire 33a in radial direction, and may be arrange | positioned.

In the following description, one of the plurality of neutral point bus bars 81 and 82 located on the holder main body 62 side (that is, the bus bar holder 61 side) is referred to as a first layer bus bar 81. Further, of the plurality of neutral point bus bars 81 and 82, the other of the plurality of neutral point bus bars 81 and 82 located outside the first layer bus bar 81 with respect to the holder main body 62 (bus bar holder 61 side) is taken as a second layer bus bar 82. Further, in the following description, the first layer bus bar 81 and the second layer bus bar 82 are collectively referred to as neutral point bus bars 81 and 82. The first layer bus bar 81 is a first system neutral point bus bar 81 connected to the coil group 7 of the first system, and the second layer bus bar 82 connected to the coil group 8 of the second system is a second system It is a neutral point bus bar 82.

FIG. 10 is a schematic cross-sectional view along the line XX in FIG. A fixing hole (through hole) 81 h and a passing hole (through hole) 81 i penetrating in the axial direction are provided in the bus bar main body portion 81 b of the first layer bus bar 81. In the bus bar main body portion 82b of the second layer bus bar 82, a fixing hole (through hole) 82h and a retraction hole (through hole) 82i penetrating in the axial direction are provided.

In the present embodiment, in the fixing holes 81h and 82h, the passage hole 81i and the retraction hole 82i, the inner regions are surrounded by the bus bar main portions 81b and 82b from four directions. However, the fixing holes 81h and 82h, the passing hole 81i and the retracting hole 82i may have a cutout shape as long as they penetrate in the axial direction. That is, in the fixing holes 81h and 82h, the passage holes 81i and the retraction holes 82i, the inner regions may be surrounded by the bus bar main portions 81b and 82b from three sides, and all the inner regions are surrounded by the bus bar main portions 81b and 82b. You do not have to.

The lower surface 62b of the holder main body 62 is provided with a plurality of shaft portions 67a, 68a, 69a and a plurality of welded portions 67b, 68b, 69b located at the tip of each of the shaft portions 67a, 68a, 69a. The welds 67 b, 68 b, 69 b are hemispherical in shape, which are convex downward. The welded portions 67b, 68b, 69b are formed by melting the tip portions of the shaft portions 67a, 68a, 69a by heat.

As shown in FIG. 9, the plurality of shaft portions 67a, 68a, 69a include three first shaft portions 67a, two second shaft portions 68a, and one third shaft portion 69a. The plurality of welds 67b, 68b and 69b are a first weld 67b located at the tip of the first shaft 67a, a second weld 68b located at the tip of the second shaft 68a, and a third shaft And a third welding portion 69b located at the tip of the portion 69a.

The first shaft portion 67 a and the first welded portion 67 b are provided to fix the first layer bus bar 81. The second shaft portion 68 a, the third shaft portion 69 a, the second welded portion 68 b and the third welded portion 69 b are provided to fix the second layer bus bar 82. Therefore, first layer bus bar 81 and second layer bus bar 82 are each fixed by three welds.

The first welded portion 67 b, the second welded portion 68 b, and the third welded portion 69 b are arranged on a single virtual circle around the central axis J. Therefore, in the heat caulking step of forming the first welded portion 67b, the second welded portion 68b, and the third welded portion 69b, the bus bar unit 60 is rotated around the central axis J, whereby the heat caulking jig is made radially. There is no need to move it. This can simplify the heat staking process.
In Drawing 9, illustration of a virtual circle in which the 1st welding part 67b, the 2nd welding part 68b, and the 3rd welding part 69b are located in a line is omitted. This virtual circle is a circle including an arc-shaped XX line shown in FIG.

As shown in FIG. 10, the first shaft portion 67a passes through the fixing hole 81h of the first layer bus bar 81. The first welded portion 67 b is located below the first layer bus bar 81. The first welded portion 67 b extends to the outside of the fixing hole 81 h of the first layer bus bar 81 when viewed in the axial direction. The first welded portion 67 b has a first fixing surface 67 d facing upward at a portion extending outward with respect to the first shaft portion 67 a. The first fixing surface 67 d contacts the lower surface 81 p of the first layer bus bar 81. Further, the upper surface 81 q of the first layer bus bar 81 contacts the lower surface 62 b of the holder main body 62. That is, the first layer bus bar 81 is sandwiched between the holder main body 62 and the first welded portion 67 b. Thereby, the first welded portion 67 b fixes the first layer bus bar 81.

The retracting hole 82i of the second layer bus bar 82 is located in a region where the first layer bus bar 81 and the second layer bus bar 82 overlap when viewed in the axial direction, and the lower side of the first welded portion 67b that fixes the first layer bus bar 81. Located in That is, the retraction hole 82i overlaps the first welded portion 67b when viewed from the axial direction. As shown in FIG. 9, when viewed from the axial direction, the first welded portion 67b is located inside the inner peripheral surface of the retraction hole 82i. That is, the first welded portion 67b is disposed in the hole of the retraction hole 82i when viewed from the axial direction.

According to the present embodiment, the first layer bus bar 81 is fixed in a region where the first layer bus bar 81 and the second layer bus bar 82 overlap by providing the retraction holes 82i in the second layer bus bar 82. Even when the one-layer bus bar 81 and the second-layer bus bar 82 are arranged close to each other in the axial direction, the interference between the first welded portion 67 b and the second-layer bus bar 82 can be suppressed.

That is, according to the present embodiment, the first layer bus bar 81 can be fixed in a region where the first layer bus bar 81 and the second layer bus bar 82 overlap. Therefore, welded portion 67 b fixing first layer bus bar 81 can be arranged in a well-balanced manner in the length direction of bus bar main portion 81 b of first layer bus bar 81. In addition, since the first layer bus bar 81 and the second layer bus bar 82 can be disposed close to each other, the bus bar unit 60 can be miniaturized in the axial direction.

As shown in FIG. 10, the second shaft 68a is provided with a step surface 68c facing the side opposite to the holder body 62 (that is, the side opposite to the bus bar holder 61, the lower side). The diameter of the second shaft portion 68a at the proximal end side (upper side) than the step surface 68c is larger than the diameter at the tip end side (lower side) than the step surface 68c.

The second shaft portion 68 a passes through the passage hole 81 i of the first layer bus bar 81 and the fixing hole 82 h of the second layer bus bar 82. The lower surface 81 p of the first layer bus bar 81 is located above the stepped surface 68 c. Therefore, the passage hole 81i of the first layer bus bar 81 is inserted into the second shaft portion 68a at the base end side with respect to the step surface 68c.

On the other hand, second layer bus bar 82 is located below step surface 68 c. The upper surface 82 q of the second layer bus bar 82 contacts the step surface 68 c. Therefore, the fixing holes 82h of the second layer bus bar 82 are inserted into the second shaft portion 68a at the tip end side of the step surface 68c.

The second welded portion 68 b is located below the second layer bus bar 82. The second welded portion 68 b extends to the outside of the fixing hole 82 h of the second layer bus bar 82 when viewed in the axial direction. The second welding portion 68 b has a second fixing surface 68 d facing upward at a portion that spreads outward with respect to the second shaft portion 68 a. The second fixing surface 68 d contacts the lower surface 82 p of the second layer bus bar 82. Since the upper surface 82 q of the second layer bus bar 82 contacts the step surface 68 c, the second layer bus bar 82 is sandwiched between the step surface 68 c and the second welded portion 68 b. Thereby, the second welded portion 68 b fixes the second layer bus bar 82.

According to the present embodiment, the second layer bus bar 82 can be fixed in a region where the first layer bus bar 81 and the second layer bus bar 82 overlap. Further, since the second shaft portion 68a passes through the passage hole 81i of the first layer bus bar 81, the first layer bus bar 81 can be positioned in a plane orthogonal to the axial direction. Note that at least a part of the outer peripheral surface of the second shaft portion 68a may be in contact with the inner peripheral surface of the passage hole 81i in the region on the proximal end side (upper side) than the step surface 68c. In this case, the positioning accuracy of the first layer bus bar 81 by the second shaft portion 68a can be enhanced.

As shown in FIG. 10, the lower surface 62b of the holder main body 62 is provided with a stepped portion 62e that protrudes downward. The step 62e has a step lower surface 62f facing downward. The third shaft portion 69a protrudes downward from the step lower surface 62f. The stepped lower surface 62 f is disposed in the area where only the second layer bus bar 82 is provided in the lower surface 62 b of the holder main body 62. The upper surface 82 q of the second layer bus bar 82 is in contact with the step lower surface 62 f.

The third shaft portion 69 a passes through the fixing hole 82 h of the second layer bus bar 82 in a region where the first layer bus bar 81 and the second layer bus bar 82 do not overlap. The third welded portion 69 b is located below the second layer bus bar 82. The third welded portion 69 b extends to the outside of the fixing hole 82 h of the second layer bus bar 82 when viewed in the axial direction. The third welded portion 69 b has a third fixed surface 69 d facing upward at a portion that spreads outward with respect to the third shaft portion 69 a. The third fixed surface 69 d contacts the lower surface 82 p of the second layer bus bar 82. That is, the second layer bus bar 82 is sandwiched between the step 62 e of the holder main body 62 and the third welded portion 69 b. Thereby, the third welded portion 69 b fixes the second layer bus bar 82.

As shown as a virtual line (two-dot chain line) in FIG. 10, an insulating sheet (insulating member) 4 may be sandwiched between the first layer bus bar 81 and the second layer bus bar 82. That is, the bus bar unit 60 may have the insulating sheet 4 interposed between the plurality of neutral point bus bars 81 and 82. The insulating sheet 4 is provided with a hole 4 h for avoiding interference with the first welded portion 67 b and the second shaft portion 68 a. By providing the insulating sheet 4 between the first layer bus bar 81 and the second layer bus bar 82, the insulation reliability between the first layer bus bar 81 and the second layer bus bar 82 can be enhanced.

In FIG. 9, the phase bus bars 71, 72, 73 disposed above the bus bar holder 61 are shown as hidden lines (broken lines). As shown in FIG. 9, at least a part of the neutral point bus bars 81 and 82 and the phase bus bars 71, 72 and 73 overlap each other when viewed from the axial direction. Thereby, bus bar unit 60 can be miniaturized in the radial direction. Further, the holder main body portion 62 of the bus bar holder 61 is interposed between the phase bus bars 71, 72, 73 and the neutral point bus bars 81, 82 in the axial direction. As a result, even when the phase bus bars 71, 72, 73 and the neutral point bus bars 81, 82 are overlapped with each other as viewed from the axial direction, the phase bus bars 71, 72, 73 and the neutral point bus bar 81 , 82 and easy to ensure insulation.

Welds 67 b, 68 b, 69 b are arranged offset from phase bus bars 71, 72, 73 as viewed in the axial direction. As described above, the welds 67 b, 68 b, 69 b are formed by melting the resin at the tips of the shanks 67 a, 68 a, 69 a. Therefore, heat is applied to the bus bar holder 61 in order to form the welds 67 b, 68 b, 69 b. The portions of the holder main body 62 overlapping the welds 67 b, 68 b, 69 b when viewed in the axial direction may be slightly deformed by heat at the time of molding the welds 67 b, 68 b, 69 b. When welding sections 67b, 68b, 69b are arranged by shifting welding sections 67b, 68b, 69b from phase bus bars 71, 72, 73 when viewed from the axial direction, the deformation when melting sections 67b, 68b, 69b is It is possible to suppress the influence on the positional accuracy of 72, 73. Thereby, the positional accuracy of the phase bus bars 71, 72, 73 can be enhanced.

In the present embodiment, among the plurality of phase bus bars 71, 72, 73, the U-phase bus bar 71 having the largest length along the circumferential direction of the bus bar main portions 71b, 72b, 73b has a diameter larger than that of the welded portions 67b, 68b. Go inside the direction. The U-phase bus bar 71 can be shortened by extending the U-phase bus bar 71 along the circumferential direction through the radially inner side of the welded portions 67 b and 68 b. As a result, the weight of the motor 1 can be reduced, and the material cost of the U-phase bus bar 71 can be saved.

In the present embodiment, the plurality of phase bus bars 71, 72, 73 are plate-shaped, and the bus bar main body portions 71b, 72b, 73b are vertically disposed with the direction orthogonal to the axial direction as the thickness direction. . When the phase bus bars 71, 72, 73 are set vertically, the phase bus bars 71, 72, 73 and the welds 67b, 68b, 69b are arranged to overlap when viewed from the axial direction. However, the radial dimension of the bus bar unit 60 does not easily increase.

In the present embodiment, one of the six welds 67 b, 68 b, 69 b is located at the root of the coil terminal 81 a of the first layer bus bar 81. That is, one welded portion 67 b radially overlaps with the coil terminal 81 a. By arranging in this manner, the positional accuracy of the coil terminal 81a can be secured, and the vibration of the coil terminal 81a can be easily suppressed. In the present embodiment, the case where only one welding portion 67 b is located at the root of the coil terminal 81 a has been described. However, all welds 67 b, 68 b, 69 b may be located at the root of the coil terminal 81 a.

The bus bar main portion 81b of the first layer bus bar 81 has a wide portion 81s provided around the passage hole 81i. Similarly, the bus bar main portion 82b of the second layer bus bar 82 has a wide portion 82s provided around the retraction hole 82i. The wide portions 81s and 82s extend outward in the width direction in a circular shape whose center coincides with the center of the passage hole 81i or the retraction hole 82i.

According to the present embodiment, by providing the wide portions 81s and 82s, even if the neutral point bus bars 81 and 82 are provided with the passage holes 81i or the retraction holes 82i, the cross-sectional areas of the busbar main portions 81b and 82b decrease. I have not. It can suppress that the electrical resistance of neutral point bus bars 81 and 82 becomes large.

In the present embodiment, the stator 30 includes two coil groups (the first coil group 7 and the second coil group 8), and the bus bar unit 60 corresponds to two phases of each phase. The motor 1 having the two phase bus bars 71, 72, 73 and the two neutral point bus bars 81, 82 corresponding to the two systems has been described. However, the number of strains is not limited. For example, the stator 30 may have only one coil group, and the bus bar unit 60 may have one phase bus bar and a neutral point bus bar. Further, stator 30 may have only three or more coil groups, and bus bar unit 60 may have three or more phases of phase bus bars and neutral point bus bars corresponding to the coil groups.

Next, an embodiment of a device on which the motor 1 of the present embodiment is mounted will be described. FIG. 11 is a schematic view of an electric power steering apparatus on which the motor 1 of the present embodiment is mounted. The electric power steering device 2 is mounted on a steering mechanism of a wheel of a car. The electric power steering device 2 is a device that reduces the steering force by hydraulic pressure. The electric power steering apparatus 2 includes a motor 1, a steering shaft 214, an oil pump 216, and a control valve 217.

The steering shaft 214 transmits an input from the steering 211 to an axle 213 having wheels 212. The oil pump 216 generates hydraulic pressure in a power cylinder 215 that transmits hydraulic driving force to the axle 213. The control valve 217 controls the oil of the oil pump 216. In the electric power steering apparatus 2, the motor 1 is mounted as a drive source of the oil pump 216. In addition, the motor 1 of this embodiment is not restricted to an electric-power-steering apparatus, You may be mounted in what kind of apparatus.

Although the embodiment and the modified example of the present invention have been described above, each configuration and the combination thereof in the embodiment and the modified example are an example, and addition and omission of the configuration are possible without departing from the spirit of the present invention , Substitution and other modifications are possible. Further, the present invention is not limited by the embodiments.

Claims (12)

1. A bus bar unit provided to the motor,
   A bus bar holder provided on an upper side of a stator annularly disposed around a vertically extending central axis;
   A first bus bar fixed to one axial side of the bus bar holder;
   And a second bus bar fixed to the other side in the axial direction of the bus bar holder,
   The bus bar holder is made of a resin material,
   The bus bar holder has a bus bar holder main body located between the first bus bar and the second bus bar in the axial direction, and a welded portion for fixing the second bus bar.
   The bus bar unit, wherein the welded portion is disposed offset from the first bus bar when viewed in the axial direction.
2. The second bus bar includes a bus bar main body extending along a plane orthogonal to the axial direction, and a coil terminal connected to a lead wire drawn from the stator.
   2. The bus bar unit according to claim 1, wherein the second bus bar has a plate shape, and at least the bus bar main body portion is disposed with an axial direction as a thickness direction.
3. The second bus bar is provided with a fixing hole penetrating in the axial direction,
   The bus bar holder has a shaft portion that protrudes from the bus bar holder main body portion and passes through the fixing hole,
   The bus bar unit according to claim 2, wherein the welded portion is located at a tip end of the shaft portion and extends to the outside of the fixing hole as viewed in the axial direction.
4. The plurality of second bus bars at least partially overlapping each other when viewed in the axial direction,
   Among the plurality of second bus bars, one of the plurality of second bus bars located on the side of the bus bar holder main body is used as a first layer bus bar, and the other located outside the first layer bus bar with respect to the bus bar holder main body is a second layer bus bar age,
   The fixing holes are provided in the first layer bus bar,
   In addition to the fixing holes, the second layer bus bar is provided with a retreating hole penetrating in the axial direction,
   The bus bar holder is
   A plurality of the shaft portions including a first shaft portion passing through the fixing hole of the first layer bus bar and a second shaft portion passing through the fixing hole of the second layer bus bar;
   A plurality of the above-mentioned plurality of the first welding portion located at the tip of the first shaft portion and including a first welding portion fixing the first layer bus bar and a second welding portion located at the tip of the second shaft portion fixing the second layer bus bar Having a weld,
   The bus bar unit according to claim 3, wherein the first welded portion is disposed in the hole of the retraction hole when viewed from the axial direction.
5. The first layer bus bar is provided with a passage hole through which the second shaft portion passes,
   The second shaft portion is provided with a step surface facing the side opposite to the bus bar holder main body portion,
   The bus bar unit according to claim 4, wherein the second layer bus bar is sandwiched between the stepped surface and the second welded portion.
6. The bus bar unit according to any one of claims 1 to 5, wherein the first bus bar extends in a circumferential direction passing radially inward of the welded portion.
7. The first bus bar has a bus bar main body extending along a plane orthogonal to the axial direction, and a coil terminal connected to a lead wire drawn from the stator,
   The bus bar unit according to any one of claims 1 to 6, wherein the first bus bar has a plate shape, and at least the bus bar main body portion is disposed in a direction orthogonal to the axial direction as a thickness direction.
8. The bus bar unit according to any one of claims 7 to 10, wherein the welding portion radially overlaps with the coil terminal.
9. The bus bar unit according to any one of claims 1 to 8, wherein the first bus bar is a phase bus bar and includes a U phase bus bar, a V phase bus bar and a W phase bus bar.
10. The bus bar unit according to any one of claims 1 to 9, wherein the second bus bar is a neutral point bus bar.
11. The bus bar unit according to any one of claims 1 to 10, comprising six of the first bus bars and two of the second bus bars.
12. A motor comprising the bus bar unit according to any one of claims 1 to 11, comprising: the stator; and a rotor radially opposed to the stator via a gap.

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