CN116982242A

CN116982242A - Rotary electric machine

Info

Publication number: CN116982242A
Application number: CN202180095996.7A
Authority: CN
Inventors: 川隅慎司; 白砂贵盛; 玉木健二; 武田浩志
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2023-10-31
Also published as: JPWO2022208762A1; WO2022208762A1

Abstract

The invention provides a rotating electrical machine. A rotating electrical machine (1) is provided with: an inner rotor (2); a stator core (20) having a plurality of teeth (24); an insulator (30) surrounding the teeth (24); coils (40U, 40V, 40W) formed by winding a winding (41) on the teeth (24) via an insulator (30); a plurality of bus bars (50N, 50U, 50V, 50W) that electrically connect the coils (40U, 40V, 40W) to each other; and a holding part (80) integrally provided on the insulator (30) and holding the plurality of bus bars (50N, 50U, 50V, 50W) so as to be separated from each other in the radial direction, and arranged at a position radially inward of the stator core (20).

Description

Rotary electric machine

Technical Field

The present invention relates to a rotating electrical machine.

Background

Conventionally, in a stator assembled in a rotating electrical machine such as a motor, coils wound around teeth of a stator core are sometimes connected to each other via a bus bar (for example, refer to patent document 1). Patent document 1 discloses a slip ring integrally molded with a resin in a state in which a plurality of annular conductive bus bars are laminated with an insulating spacer, which is an insulating resin molded material, interposed therebetween.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2019-154084

Disclosure of Invention

Summary of the invention

Problems to be solved by the invention

However, in the above prior art, in forming the slip ring, a spacer is required in addition to the bus bar, and the resin needs to be molded. Therefore, the manufacturing cost of the rotating electrical machine may increase due to the use of the slip ring.

The invention provides a rotary motor capable of reducing manufacturing cost and providing bus bars for connecting coils.

Means for solving the problems

The rotating electrical machine according to the first aspect of the present invention includes: an inner rotor (2) having permanent magnets (10); a stator core (20) having a plurality of teeth (24) in the circumferential direction, the stator core being disposed radially outward of the inner rotor (2); an insulator (30) surrounding the teeth (24); a coil (40U, 40V, 40W) formed by winding a winding (41) on the teeth (24) through the insulator (30); a plurality of bus bars (50N, 50U, 50V, 50W) that electrically connect the coils (40U, 40V, 40W) to each other; and a holding portion (80) integrally provided to the insulator (30) and configured to hold the plurality of bus bars (50N, 50U, 50V, 50W) so as to be separated from each other in the radial direction, the bus bars being disposed on the inner side in the radial direction of the stator core (20).

According to this configuration, the holding portion for holding the bus bar is integrally provided to the insulator, and therefore, the number of components can be reduced as compared with a configuration in which the components for holding the bus bar are provided separately from the insulator. Therefore, it is possible to realize a reduction in manufacturing cost and provide the bus bar. Further, the holding portion is disposed radially inward of the stator core, whereby the rotating electrical machine can be prevented from being enlarged in the radial direction. Therefore, the rotary electric machine can be miniaturized.

The rotating electrical machine according to the second aspect of the present invention is the rotating electrical machine according to the first aspect, wherein the holding portion (80) may have an insulating wall (82) interposed between the plurality of bus bars (50N, 50U, 50V, 50W).

With the above configuration, the bus bars can be insulated from each other by the holding portion without using other members such as spacers. Therefore, the number of parts can be reduced, and the manufacturing cost can be reduced.

The rotating electrical machine according to a third aspect of the present invention is the rotating electrical machine according to the first or second aspect, wherein the winding (41) includes lead-out portions (42, 43) extending from the coils (40U, 40V, 40W) inward in the radial direction and connected to any one of the plurality of bus bars (50N, 50U, 50V, 50W), and a slit (37) through which the lead-out portions (42, 43) pass is formed in the insulator (30).

With the above configuration, the lead portion can be positioned with respect to the holding portion integral with the insulator, and therefore, the winding can be easily laid on the bus bar held by the holding portion.

A rotating electrical machine according to a fourth aspect of the present invention is the rotating electrical machine according to any one of the first to third aspects, wherein each of the plurality of bus bars (50U, 50V, 50W) has a winding connection portion (52) extending radially outward and connected to the winding (41), a plurality of holding grooves (83) in which the plurality of bus bars (50U, 50V, 50W) are arranged are formed in the holding portion (80), and the holding portion (80) has an abutment portion (85) in contact with the winding connection portion (52) at a position radially outward of the plurality of holding grooves (83).

With the above configuration, the contact portion is arranged at a position radially outside the portions held by the plurality of holding grooves, respectively, in the bus bar. Thus, the winding connection portions of the bus bars connected to the coils of any phase can be positioned by the abutting portions using the holding portions having the same structure. Therefore, it is not necessary to separately use an insulator for integrating the holding portion according to the phase of the coil, and the component for integrating the insulator and the holding portion can be used in common. Therefore, the increase in the types of components can be suppressed, and the manufacturing cost can be reduced.

A rotating electrical machine according to a fifth aspect of the present invention is the rotating electrical machine according to any one of the first to fourth aspects, wherein the rotating electrical machine further includes a housing (105) for fixing the stator core (20), and the holding portion (80) is disposed between the inner rotor (2) and the housing (105).

If the holding portion is disposed on the opposite side of the housing with the inner rotor interposed therebetween, the holding portion becomes an obstacle, and it is difficult to assemble the inner rotor after the stator core is fixed to the housing. With the above configuration, the holding portion is not disposed in the region through which the inner rotor passes during the process of assembling the inner rotor to the predetermined position. This makes it possible to assemble the inner rotor with the stator core 20 fixed to the housing. Therefore, the manufacturing cost can be reduced by simplifying the manufacturing process.

A rotating electrical machine according to a sixth aspect of the present invention is the rotating electrical machine according to the fifth aspect, wherein the bus bar (50U, 50V, 50W) has a three-phase wire connecting portion (53) extending in an axial direction and connected to a three-phase wire (60), and the three-phase wire connecting portion (53) is fastened to the three-phase wire (60) in the radial direction.

In the case of fastening the three-phase wire connecting portion and the three-phase wire in the axial direction, it is assumed that the connecting portion of the three-phase wire connecting portion and the three-phase wire is provided so as to protrude further in the axial direction from the three-phase wire connecting portion extending in the axial direction. Further, when the three-phase line connecting portion and the three-phase line are fastened in the circumferential direction, the connecting portion between the three-phase line connecting portion and the three-phase line may be enlarged in the radial direction or the axial direction. With the above configuration, the three-phase connection portion and the three-phase connection portion can be disposed in the limited space between the inner rotor and the housing. In addition, in the space near the rotation axis, interference between the three-phase line connection portion and other members such as the rotation shaft fixed to the inner rotor can be suppressed. Therefore, the distance between the inner rotor and the housing can be prevented from being increased, and the rotary electric machine can be miniaturized.

A rotating electrical machine according to a seventh aspect of the present invention is the rotating electrical machine according to any one of the first to sixth aspects, wherein the bus bar (50U, 50V, 50W) has a three-phase line connecting portion (53) extending in an axial direction and fastened to a terminal (61) of a three-phase line (60), the three-phase line connecting portion (53) includes an engaging portion (54) engaged with the terminal (61), and the engaging portion (54) is brought into contact with the terminal (61) from a rotation direction of a fastening member (71).

With the above configuration, when the terminal is fastened to the three-phase wire connecting portion by rotating the fastening member, the terminal is brought into contact with the engagement portion of the three-phase wire connecting portion, so that the common rotation of the terminal with respect to the three-phase wire connecting portion can be restricted, and the three-phase wire connecting portion and the terminal can be positioned with each other.

An eighth aspect of the present invention is the rotary electric machine according to the seventh aspect, wherein the rotary electric machine includes a fastening member group (70), the fastening member group (70) includes a first fastening member (71) and a second fastening member (72) screwed to the first fastening member (71), the three-phase line connecting portion (53) and the terminal (61) are fastened, and one of the first fastening member (71) and the second fastening member (72) is abutted against one of the three-phase line connecting portion (53) and the terminal (61) in a rotation direction of the other of the first fastening member (71) and the second fastening member (72).

With the above configuration, since the rotation of one of the first fastening member and the second fastening member is restricted by one of the three-phase line connecting portion and the terminal, the other of the first fastening member and the second fastening member can be screwed with the one by merely rotating the other of the first fastening member and the second fastening member. Therefore, the manufacturing process can be simplified.

Effects of the invention

According to the rotating electrical machine described above, it is possible to realize a reduction in manufacturing cost, and to provide a bus bar connecting coils to each other.

Drawings

Fig. 1 is a view of a power unit of an embodiment as viewed from the axial direction.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a view of the rotor and stator of the embodiment as viewed from the axial direction.

Fig. 4 is a perspective view showing an insulator and a holding portion according to an embodiment.

Fig. 5 is a perspective view showing a main part of the stator according to the embodiment.

Fig. 6 is a view of the bus bar of the embodiment as viewed from the axial direction.

Fig. 7 is a perspective view of a bus bar showing each phase of the embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or similar structures are denoted by the same reference numerals. In addition, a repetitive description of these structures may be omitted.

Fig. 1 is a view of a power unit of an embodiment as viewed from the axial direction. Fig. 2 is a sectional view taken along line II-II of fig. 1.

As shown in fig. 1 and 2, the rotary electric machine 1 is an inner rotor type three-phase permanent magnet synchronous motor. The rotating electrical machine 1 is a traveling motor mounted on a vehicle such as an electric two-wheeled vehicle. The rotary electric machine 1 includes a cylindrical rotor 2, a stator 3 surrounding the rotor 2, a rotary shaft 4 fixed to the rotor 2, and a motor case 102 accommodating the rotor 2 and the stator 3. In the present embodiment, the rotary electric machine 1 is a part of the power unit 100. The power unit 100 includes a rotary electric machine 1, a speed reducer (not shown) that reduces the drive rotation of the rotary electric machine 1 and outputs the reduced drive rotation, and a power unit case 101 that forms the outer contour of the power unit 100. The power unit housing 101 will be described later. The rotor 2, the stator 3, and the rotary shaft 4 are disposed with the axis C as a common axis. Hereinafter, the direction in which the axis C extends will be referred to as an axial direction, the direction orthogonal to the axis C will be referred to as a radial direction, and the direction in which the axis C rotates will be referred to as a circumferential direction.

As shown in fig. 1, the rotor 2 is a buried magnet type rotor. The rotor 2 is rotatable about an axis C. The rotor 2 includes a permanent magnet 10 and a rotor core 11 holding the permanent magnet 10.

The rotor core 11 is formed in a cylindrical shape extending in the axial direction. The rotor core 11 is formed by stacking a plurality of electromagnetic steel plates in the axial direction, for example. The rotor core 11 may be a so-called dust core in which metal magnetic powder (soft magnetic powder) is compression-molded. The permanent magnet 10 is held by the outer peripheral portion of the rotor core 11. The outer peripheral portion includes a plurality of magnetic pole portions 12. The magnetic pole portions 12 are equally disposed in the circumferential direction. A pair of magnet slots 13 into which the permanent magnets 10 are inserted are formed in each of the magnetic pole portions 12. The magnet insertion slot 13 penetrates the rotor core 11 in the axial direction.

The permanent magnet 10 is a rare earth magnet. Examples of the rare earth magnet include neodymium magnets, samarium cobalt magnets, and praseodymium magnets. The permanent magnets 10 are inserted into the magnet slots 13 of the rotor core 11, and are fixed to the rotor core 11 by, for example, resin, adhesive, or the like. The permanent magnet 10 is magnetized in the radial direction. The permanent magnet 10 is configured such that the plurality of magnetic pole portions 12 alternately reverse the magnetization direction in the circumferential direction.

As shown in fig. 3, the stator 3 is a 3-phase Y-wired salient pole winding stator. The stator 3 includes a stator core 20, an insulator 30, coils 40U, 40V, 40W, bus bars 50N, 50U, 50V, 50W, and a holding portion 80.

The stator core 20 is formed by arranging a plurality of (12 in the present embodiment) divided cores 22 in a ring shape in the circumferential direction. For example, the divided cores 22 are formed by stacking a plurality of T-shaped electromagnetic steel plates punched by punching. The divided core 22 includes a back yoke piece 23 extending in the circumferential direction and teeth 24 extending radially inward from the back yoke piece 23. The back yoke piece 23 is connected in the circumferential direction by the divided cores 22 to form an annular back yoke 21 of the stator core 20. The teeth 24 are connected in the circumferential direction by the split cores 22 to form slots 26 between adjacent teeth 24. The radially inner end of the tooth 24 faces the magnetic pole 12 (see fig. 1) of the rotor 2. The divided cores 22 connected in the circumferential direction are fixed to each other by a stator ring 28 (see fig. 1).

As shown in fig. 3 and 4, an insulator 30 is attached to each of the divided cores 22 so as to surround the teeth 24. The insulator 30 is formed of an electrically insulating material such as resin. The insulator 30 is divided into two parts, a first insulator 30A and a second insulator 30B. The dividing positions of the first insulator 30A and the second insulator 30B are located at the axial intermediate portions of the teeth 24. The intermediate portion may be located between one end and the other end of the tooth 24 in the axial direction. The first insulator 30A covers an end surface of the tooth 24 in the first axial direction and a first axial direction portion of both side surfaces in the circumferential direction. The second insulator 30B covers the second axial direction end surface of the tooth 24 in the second axial direction and the second axial direction portion of the both circumferential side surfaces.

The insulator 30 includes an inner peripheral wall 31 along the outer peripheral surface of the tooth 24, an inner flange 32 protruding from the radially inner end edge of the inner peripheral wall 31, and an outer flange 33 protruding from the radially outer end edge of the inner peripheral wall 31. The inner peripheral wall 31, the inner flange 32, and the outer flange 33 are formed on both the first insulator 30A and the second insulator 30B. The inner peripheral wall 31, the inner flange 32, and the outer flange 33 are disposed so as to surround the teeth 24 over the entire circumference except for the dividing positions of the first insulator 30A and the second insulator 30B. The inner peripheral wall 31, the inner flange 32, and the outer flange 33 are integrally formed on the first insulator 30A and the second insulator 30B, respectively. Winding grooves 34 in which coils 40U, 40V, 40W are arranged are formed between the inner flange 32 and the outer flange 33, and the coils 40U, 40V, 40W are wound around the inner peripheral wall 31.

As shown in fig. 4, the first insulator 30A is formed with a turning locking portion 36 and a pair of slits 37. The steering locking portion 36 is a convex portion protruding from the outer flange 33. The steering locking portion 36 protrudes in the first direction from an end edge of the outer flange 33 in the first direction in the axial direction. A slit 37 is formed in the inner flange 32. The slit 37 is formed at an end edge of the inner flange 32 in the first axial direction. The slits 37 are formed at intervals in the circumferential direction.

As shown in fig. 3, the coils 40U, 40V, 40W are formed by winding the winding 41 around the teeth 24 via the insulator 30. The coils 40U, 40V, 40W are wound around the inner peripheral wall 31 of the insulator 30, and are located between the inner flange 32 and the outer flange 33. The coils 40U, 40V, 40W are U-phase coil 40U, V-phase coil 40V and W-phase coil 40W arranged with a phase difference of 120 ° therebetween in the circumferential direction. The U-phase coil 40U, V phase coil 40V and the W-phase coil 40W are sequentially arranged in the circumferential direction. One end of each coil 40U, 40V, 40W is commonly electrically connected to the neutral point of the Y-wire. The other ends of the coils 40U, 40V, and 40W are electrically connected in common to electric wires of respective phases of a three-phase line 60 described later.

As shown in fig. 5, the winding 41 includes a pair of lead portions 42, 43 extending radially inward from the coils 40U, 40V, 40W. The pair of lead portions 42, 43 includes: a first lead-out portion 42 extending from a winding end portion of the coils 40U, 40V, 40W toward the first end portion 41a of the winding 41; and a second lead-out portion 43 extending from the second end portion 41b of the winding 41 toward the winding start portion of the coils 40U, 40V, 40W. The first lead-out portion 42 and the second lead-out portion 43 extend in the first axial direction from the winding groove 34. The first lead-out portion 42 passes through one of the slits 37 of the first insulator 30A. The portion of the first lead-out portion 42 closer to the coils 40U, 40V, 40W than the slit 37 is wound one turn around the turn locking portion 36 of the first insulator 30A. The second lead-out portion 43 passes through the other slit 37 of the first insulator 30A.

As shown in fig. 3 and 6, the bus bars 50N, 50U, 50V, 50W electrically connect the coils 40U, 40V, 40W to each other. The bus bars 50N, 50U, 50V, 50W are neutral point bus bar 50N, U phase bus bar 50U, V phase bus bar 50V and W phase bus bar 50W. The neutral point bus bar 50N is connected to the first end 41a of the winding 41 forming the coils 40U, 40V, 40W. The neutral point bus bars 50N are arranged in the circumferential direction so as to be connected one by one to the windings 41 of the U-phase coil 40U, V phase coil 40V and the W-phase coil 40W, which are arranged continuously in the circumferential direction. In the present embodiment, four coils 40U, 40V, 40W of each phase are provided, and therefore, four neutral point bus bars 50N are provided. The U-phase bus bar 50U is connected to all of the second end portions 41b of the windings 41 forming the U-phase coil 40U. The V-phase bus bar 50V is connected to all of the second end portions 41b of the windings 41 forming the V-phase coil 40V. The W-phase bus bar 50W is connected to all of the second end portions 41b of the windings 41 forming the W-phase coil 40W. The bus bars 50N, 50U, 50V, 50W are disposed inside the insulators 30 arranged in a ring shape as viewed from the axial direction. The bus bars 50N, 50U, 50V, 50W are formed of a metal plate. The bus bars 50N, 50U, 50V, 50W include: a winding connection portion 52 connected to the winding 41; and a connection portion 51 for connecting the winding connection portions 52.

Fig. 7 is a perspective view of a bus bar showing each phase of the embodiment.

As shown in fig. 6 and 7, the connecting portion 51 has a thickness in the radial direction and extends with a substantially constant width in the circumferential direction. The coupling portions 51 of the neutral point bus bars 50N are arranged at equal intervals in the circumferential direction. The coupling portions 51 of the neutral point bus bar 50N, U, the phase bus bar 50U, V, and the phase bus bar 50V and the phase bus bar 50W are disposed at radial intervals at predetermined positions in the axial direction. In the present embodiment, the connection portion 51 of the W-phase bus bar 50W, the connection portion 51 of the V-phase bus bar 50V, the connection portion 51 of the U-phase bus bar 50U, and the connection portion 51 of the neutral point bus bar 50N are arranged in this order toward the radial outside. The connecting portion 51 of the neutral point bus bar 50N, U phase bus bar 50U, V phase bus bar 50V and the W phase bus bar 50W has a radius of curvature corresponding to the arrangement position in the radial direction so as not to intersect with each other.

As shown in fig. 5 to 7, the winding connection portion 52 is connected to the winding 41. The winding connection portion 52 extends radially outward from the coupling portion 51 as viewed in the axial direction. The winding connection portion 52 is integrally formed with the connection portion 51. In the present embodiment, since the neutral point bus bar 50N is connected to one of the windings 41 of the coils 40U, 40V, and 40W of each phase, the neutral point bus bar 50N has three winding connection portions 52 extending from the connection portions 51. In the present embodiment, since four coils 40U, 40V, and 40W are provided for each phase, the winding connection portion 52 extends from the connection portion 51 by four in the bus bars 50U, 50V, and 50W for each phase.

As shown in fig. 5, the winding connection portion 52 extends outward in the axial direction (first direction) from the connection portion 51, and then is bent outward in the radial direction and extends outward in the radial direction. The radially outer tip end of the winding connection portion 52 is located radially outward of the plurality of holding grooves 83 described later, and is close to the inner flange 32 of the insulator 30. The distal end portion of the winding connection portion 52 is folded back to the outside in the axial direction, sandwiching the winding 41. The winding connection portion 52 of the neutral point bus bar 50N sandwiches the first end portion 41a of the winding 41. The winding connection portions 52 of the bus bars 50U, 50V, 50W of the respective phases sandwich the second end 41b of the winding 41. Thereby, the neutral point bus bar 50N electrically connects the U-phase coil 40U, V phase coil 40V and the W-phase coil 40W, which are arranged continuously in the circumferential direction, to each other. The bus bars 50U, 50V, 50W of the respective phases electrically connect the coils 40U, 40V, 40W of the same phase to each other.

As shown in fig. 7, the bus bars 50U, 50V, 50W of each phase further include a three-phase wire connecting portion 53 extending from the connecting portion 51. The three-phase wire connecting portion 53 extends axially outward from the intermediate portion of the connecting portion 51. The three-phase wire connecting portion 53 is integrally formed with the connecting portion 51. The entirety of the three-phase wire connecting portion 53 has a thickness in the radial direction. A through hole 53h is formed in the three-phase wire connecting portion 53. The through hole 53h penetrates the axially outer tip of the three-phase wire connecting portion 53 in the radial direction. The shaft portion of the bolt 71 to which the terminal 61 of the three-phase wire 60 is fastened is inserted into the through hole 53h. Three-phase wire connecting portion 53 has engaging portion 54 that engages with terminal 61 of three-phase wire 60. The engagement portion 54 protrudes in the circumferential direction. Specifically, the engaging portions 54 of the U-phase and W-phase bus bars 50U and 50W protrude clockwise as viewed in the extending direction (first direction) of the axially three-phase wire connecting portion 53. The engaging portion 54 of the V-phase bus bar 50V protrudes counterclockwise as viewed from the protruding direction of the three-phase wire connecting portion 53 in the axial direction. The three-phase wire connection portions 53 of the U-phase bus bar U, V and the W-phase bus bar 50V are arranged so as to be offset from each other in the circumferential direction.

The terminals 61 of the three-phase line 60 are connected to the three-phase line connection portion 53. The three-phase line terminals 61 are provided for each phase. In the present embodiment, the terminals 61 are formed in the same shape as each other. The terminal 61 is formed of metal. The terminal 61 includes: a fastening portion 62 fastened to the three-phase wire connecting portion 53; and a caulking portion 65 mechanically and electrically connected to the fastening portion 62 and coupled to the tip of the electric wire of the three-phase wire 60. The fastening portion 62 includes: a base 63 overlapping the front end of three-phase wire connecting portion 53; and a pair of side portions 64 extending in the same direction from the base portion 63. Base 63 overlaps the distal end portion of three-phase wire connecting portion 53 from the radially outer side. A through hole (not shown) concentric with the through hole 53h penetrating the three-phase wire connecting portion 53 is formed in the base portion 63. A pair of side portions 64 extend from both circumferential side edges of the base portion 63. The pair of side portions 64 extend to the axis C side so as to be inclined at substantially 90 ° with respect to the base portion 63. The pair of side portions 64 are disposed so as to sandwich the distal end portion of the three-phase wire connecting portion 53 from the outer side in the circumferential direction. One side portion 64 of the pair of side portions 64 is in contact with the engagement portion 54 of the three-phase wire connecting portion 53 in a clockwise direction around the through hole 53h as viewed from the outside in the radial direction. The caulking portion 65 is connected to the other side portion 64 of the pair of side portions 64. The electric wire of the three-phase wire 60 is coupled to the caulking portion 65 so as to extend toward the opposite side of the engagement portion 54 with the tip end portion of the three-phase wire connecting portion 53 as the center.

The terminals 61 of the three-phase wire connecting portion 53 and the three-phase wire 60 are fastened in the radial direction by the fastening member group 70. The fastening member group 70 includes a bolt 71 (first fastening member) and a nut 72 (second fastening member) screwed with the bolt 71. The bolt 71 is inserted into the through hole 53h of the three-phase wire connecting portion 53 and the through hole of the terminal 61 from the radially outer side. The nut 72 is a square nut. The nut 72 is screwed to the shaft of the bolt 71 with the base 63 and the three-phase wire connecting portion 53 of the terminal 61 interposed between the nut and the head of the bolt 71. The nut 72 abuts against the pair of side portions 64 of the terminal 61 in the clockwise direction around the through hole 53h as viewed from the outside in the radial direction. The clockwise direction around the through hole 53h as viewed from the outside in the radial direction is the rotational direction at the time of screwing the bolt 71.

As shown in fig. 4 and 5, the holding portion 80 is provided for each coil 40U, 40V, 40W. The holding portion 80 is integrally provided to the first insulator 30A by being integrally formed with the first insulator 30A. The holding portion 80 is disposed radially inward of the stator core 20 in a first direction with respect to the axial direction of the rotor 2. The plurality of holding portions 80 are arranged in a ring shape in the circumferential direction. The holding portion 80 holds the connecting portions 51 of the plurality of bus bars 50N, 50U, 50V, 50W so as to be separated from each other in the radial direction.

The holding unit 80 includes: a bottom 81 extending radially inward from the inner flange 32 of the insulator 30; and an insulating wall 82 rising from the bottom 81 to the outside in the axial direction (first direction). The bottom portion 81 extends along an end surface of the rotor core 11 in the first direction in the axial direction. The bottom 81 extends radially inward from the inner flange 32 while narrowing its circumferential width when viewed from the axial direction. The insulating wall 82 is formed in plurality at each holding portion 80. In the present embodiment, five insulating walls 82 are formed for each holding portion 80. The insulating walls 82 extend in an arc shape in the circumferential direction and are formed at intervals in the radial direction. A holding groove 83 in which the connecting portions 51 of the bus bars 50N, 50U, 50V, 50W are arranged is formed between the insulating walls 82 adjacent in the radial direction. The holding groove 83 is opened in the first axial direction and extends in a circular arc shape in the circumferential direction. By arranging all the holding portions 80 in a ring shape, the holding grooves 83 each extend in a ring shape as a whole. In the present embodiment, four holding grooves 83 are formed in the radial direction. The three holding grooves 83 located radially inward of the four holding grooves 83 are provided with the connecting portions 51 of the bus bars 50U, 50V, 50W of each phase. Further, the connecting portion 51 of the neutral point bus bar 50N is arranged in the holding groove 83 located on the outermost radial direction among the four holding grooves 83. Thereby, the insulating wall 82 is sandwiched between the plurality of bus bars 50N, 50U, 50V, 50W. In the following description, the plurality of insulating walls 82 are referred to as a first insulating wall, a second insulating wall, a third insulating wall, a fourth insulating wall, and a fifth insulating wall in this order from the insulating wall 82 located on the innermost side in the radial direction to the outer side in the radial direction.

The fourth insulating wall 82 is formed higher than the second insulating wall 82 and the third insulating wall 82 with respect to the bottom 81. Specifically, the end edge in the first axial direction of the fourth insulating wall 82 is located at a position closer to the first axial direction than the end edge in the first axial direction of each of the second insulating wall 82 and the third insulating wall 82. The end edge of the fourth insulating wall 82 in the first axial direction is in contact with the winding connection portion 52 in the first axial direction.

The holding unit 80 includes: a first contact portion 85 (contact portion) that contacts the winding connection portion 52 of the bus bar 50U, 50V, 50W of each phase; and a second abutting portion 86 abutting against the winding connection portion 52 of the neutral point bus bar 50N. The first abutting portion 85 axially protrudes from an end edge of the fourth insulating wall 82 in the first axial direction. The first contact portion 85 contacts the winding connection portion 52 of the bus bars 50U, 50V, 50W of each phase from one side in the circumferential direction. Thereby, the first abutting portion 85 positions the winding connection portions 52 of the bus bars 50U, 50V, 50W of the respective phases in the circumferential direction. The second abutting portion 86 axially protrudes from an end edge of the fifth insulating wall 82 in the first axial direction. The second contact portion 86 is provided so as to be offset to one of the circumferential directions with respect to the first contact portion 85. The second contact portion 86 contacts the winding connection portion 52 of the neutral point bus bar 50N from one side in the circumferential direction. Thereby, the second abutting portion 86 positions the winding connection portion 52 of the neutral point bus bar 50N in the circumferential direction.

The holding portion 80 has a through hole 87. The through hole 87 is formed between the fifth insulating wall 82 and the inner flange 32. The through hole 87 penetrates the holding portion 80 in the axial direction. The through holes 87 are formed in a pair at each holding portion 80 at intervals in the circumferential direction. The through hole 87 overlaps the distal end portion of the winding connection portion 52 as viewed in the axial direction. Specifically, one of the pair of through holes 87 overlaps the connection portion of the winding connection portion 52 of the neutral point bus bar 50N and the first end portion 41a of the winding 41 as viewed from the axial direction. The other of the pair of through holes 87 overlaps the connection portion between the winding connection portion 52 of the bus bar 50U, 50V, 50W of each phase and the second end portion 41b of the winding 41 when viewed from the axial direction.

As shown in fig. 2, the power unit case includes the motor case 102 and the decelerator case 103 accommodating the decelerator. The motor housing 102 and the speed reducer housing 103 are arranged in the axial direction. The rotation shaft 4 fixed to the rotor 2 penetrates a partition wall 104 that divides the internal space of the motor case 102 from the internal space of the speed reducer case 103. The motor case 102 includes a case body 105 (housing) that is open on the opposite side of the reduction gear case 103 in the axial direction. The outer peripheral portion of the stator core 20 is fastened and fixed to the housing body 105 from the side opposite to the speed reducer housing 103. The rotor 2 and the stator 3 are arranged such that the holding portion 80 is located between the housing body 105 and the rotor 2. That is, the holding portion 80 and the bus bars 50N, 50U, 50V, 50W are arranged between the rotor 2 and the speed reducer case 103 in the axial direction. The opening of the housing body 105 is closed by a cover, not shown.

As described above, the rotary electric machine 1 of the present embodiment includes: a plurality of bus bars 50N, 50U, 50V, 50W electrically connecting the coils 40U, 40V, 40W to each other; a holding portion 80 integrally provided on the insulator 30 and configured to hold the plurality of bus bars 50N, 50U, 50V, and 50W so as to be separated from each other in the radial direction, and disposed radially inward of the stator core 20. According to this configuration, the holding portions 80 that hold the bus bars 50N, 50U, 50V, and 50W are integrally provided to the insulator 30, and therefore, the number of components can be reduced as compared with a configuration in which the components that hold the bus bars are provided separately from the insulator. Therefore, the bus bars 50N, 50U, 50V, 50W can be provided while achieving a reduction in manufacturing cost. Further, by disposing the holding portion 80 on the radially inner side of the stator core 20, the rotating electrical machine 1 can be prevented from being enlarged in the radial direction. Therefore, the rotary electric machine 1 can be miniaturized.

The holding portion 80 has an insulating wall 82 interposed between the plurality of bus bars 50N, 50U, 50V, 50W. According to this structure, the bus bars 50N, 50U, 50V, and 50W can be insulated from each other by the holding portion without using other members such as spacers. Therefore, the number of parts can be reduced, and the manufacturing cost can be reduced.

The winding 41 includes lead portions 42 and 43 extending radially inward from the coils 40U, 40V, and 40W and connected to any one of the plurality of bus bars 50N, 50U, 50V, and 50W. The insulator 30 is formed with a slit 37 through which the lead-out portions 42 and 43 pass. According to this configuration, since the lead portions 42 and 43 of the winding 41 can be positioned with respect to the holding portion 80 integral with the insulator 30, the winding 41 can be easily laid out with respect to the bus bars 50N, 50U, 50V, 50W held by the holding portion 80.

The plurality of bus bars 50U, 50V, 50W each have a winding connection portion 52 extending radially outward and connected to the winding 41. The holding portion 80 is formed with a plurality of holding grooves 83 in which the plurality of bus bars 50U, 50V, 50W are arranged individually. The holding portion 80 has a first contact portion 85 that contacts the winding connection portion 52 at a position radially outward of the plurality of holding grooves 83. According to this configuration, the first contact portion 85 is disposed radially outward of the connecting portions 51 of the bus bars 50U, 50V, and 50W held by the plurality of holding grooves 83, respectively. Thus, the winding connection portions 52 of the bus bars 50U, 50V, 50W connected to any one of the coils 40U, 40V, 40W can be positioned by the abutting portions 85 using the holding portions 80 having the same structure. Therefore, it is not necessary to use the insulator 30 having the holding portion 80 integrated therein separately according to the phases of the coils 40U, 40V, and 40W, and it is possible to realize the versatility of the components integrating the insulator 30 and the holding portion 80. Therefore, the increase in the types of components can be suppressed, and the manufacturing cost can be reduced.

The holding portion 80 is disposed between the rotor 2 and the housing body 105 of the motor housing 102. If the holding portion is disposed on the opposite side of the housing body 105 with the rotor 2 interposed therebetween, the holding portion becomes an obstacle, and it is difficult to assemble the rotor 2 after the stator core is fixed to the housing body 105. According to the present embodiment, the holding portion 80 is not disposed in the region through which the rotor 2 passes during the process of assembling the rotor 2 to the predetermined position. Thereby, the rotor 2 can be assembled in a state where the stator core 20 is fixed to the housing body 105. Therefore, the manufacturing cost can be reduced by simplifying the manufacturing process.

The bus bars 50U, 50V, 50W have three-phase wire connecting portions 53 extending in the axial direction and connected to the three-phase wires 60. Three-phase wire 60 is radially secured to three-phase wire connecting portion 53. In the case of fastening the three-phase wire connecting portion and the three-phase wire in the axial direction, it is assumed that the connecting portion of the three-phase wire connecting portion and the three-phase wire is provided so as to protrude further in the axial direction from the three-phase wire connecting portion extending in the axial direction. Further, when the three-phase line connecting portion and the three-phase line are fastened in the circumferential direction, the size of the connecting portion between the three-phase line connecting portion and the three-phase line increases in the radial direction or the axial direction. According to the present embodiment, the three-phase connection 53 and the connection of the three-phase line 60 can be disposed in the limited space between the rotor 2 and the housing body 105. In addition, in the space near the axis C, interference between the three-phase wire connection portion 53 and the connection portion of the three-phase wire 60 and other members such as the rotary shaft 4 fixed to the rotor 2 can be suppressed. Therefore, the rotary electric machine 1 can be miniaturized while suppressing an increase in the distance between the rotor 2 and the housing body 105.

Three-phase wire 60 has a terminal 61 secured to three-phase wire connection 53. The three-phase wire connecting portion 53 includes an engaging portion 54 that engages with the terminal 61. The terminal 61 abuts against the engagement portion 54 in the rotation direction of the bolt 71. According to this configuration, when the bolt 71 is rotated to fasten the terminal 61 to the three-phase wire connecting portion 53, the terminal 61 is brought into contact with the engagement portion 54 of the three-phase wire connecting portion 53, so that the common rotation of the terminal 61 with respect to the three-phase wire connecting portion 53 can be restricted, and the three-phase wire connecting portion 53 and the terminal 61 can be positioned with each other.

The nut 72 that fastens the three-phase wire connecting portion 53 and the terminal 61 abuts against the terminal 61 in the rotation direction of the bolt 71. According to this structure, the rotation of the nut 72 is restricted by the terminal 61, and therefore, the bolt 71 can be screwed with the nut 72 only by rotating the bolt 71. Therefore, the manufacturing process can be simplified.

The present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications are conceivable within the technical scope thereof.

For example, in the above-described embodiment, the rotating electrical machine 1 is a three-phase permanent magnet synchronous motor including an inner rotor embedded with magnets, but the application scope of the present invention is not limited thereto. For example, the rotating electric machine may be a motor including a surface magnet type inner rotor having magnets mounted on an outer peripheral surface of a rotor core. The present invention is also applicable to motors including a plurality of bus bars electrically connecting coils to each other, such as a three-phase ac motor, a brushless DC motor, and other than a three-phase permanent magnet synchronous motor, and to generators having the same structure as those motors.

In the above embodiment, the arrangement of the neutral point bus bar 50N and the bus bars 50U, 50V, 50W of the respective phases in the holding portion is not particularly limited. For example, the connecting portion of the neutral point bus bar may be disposed radially inward of the connecting portion of the bus bar of each phase.

In the above embodiment, the bolts 71 are screwed from the outside in the radial direction at the connecting portions of the bus bars 50U, 50V, 50W and the three-phase line 60, while the terminals 61 and the three-phase line connecting portions 53 are overlapped from the outside in the radial direction. The side portion 64 of the terminal 61 is brought into contact with the engagement portion 54 of the three-phase wire connecting portion 53 in the rotational direction at the time of screwing the bolt 71, whereby the common rotation of the terminal 61 is restricted. However, the structure of the connecting portion of the bus bar and the three-phase line is not particularly limited. For example, the terminals may overlap the three-phase wire connecting portion from the radially inner side. In this case, as in the present embodiment, it is preferable that the members that are rotatable together at the time of fastening are rotation-restricted by engagement of the three-phase wire connection portion and the terminal. The positional relationship between the bolt 71 and the nut 72 may be reversed, and the head of the bolt 71 may be brought into contact with the pair of side portions 64 of the terminal 61 in the rotational direction at the time of screwing the nut 72.

In the above embodiment, the first contact portion 85 that contacts the winding connection portion 52 of the bus bars 50U, 50V, 50W of each phase is formed in the fourth insulating wall 82, but the present invention is not limited to this configuration. The first abutting portion may be formed on the fifth insulating wall.

The components in the above embodiments may be replaced with known components as appropriate within a range not departing from the gist of the present invention.

Symbol description

1 rotating electric machine

2 rotor (inner rotor)

10. Permanent magnet

20. Stator core

24. Teeth

30. Insulation body

37. Slit(s)

40U, 40V, 40W coil

41 windings

42 first lead-out portion (lead-out portion)

43 second lead-out portion (lead-out portion)

50N neutral point bus bar (bus bar)

50U U phase bus bar (bus bar)

50V V phase bus bar (bus bar)

50W W phase bus bar (bus bar)

52. Winding connection

53. Three-phase line connecting part

54. Engagement portion

60. Three phase line

61. Terminal for connecting a plurality of terminals

70. Fastening component group

71 bolt (fastening component, first fastening component)

72 nut (second fastening component)

80. Holding part

82. Insulating wall

83. Retaining groove

85 first contact portion (contact portion)

105 housing body (shell).

Claims

1. A rotating electrical machine is provided with:

an inner rotor (2) having permanent magnets (10);

a stator core (20) which has a plurality of teeth (24) in the circumferential direction and is arranged radially outside the inner rotor (2);

an insulator (30) surrounding the teeth (24);

a coil (40U, 40V, 40W) formed by winding a winding (41) on the teeth (24) through the insulator (30);

a plurality of bus bars (50N, 50U, 50V, 50W) that electrically connect the coils (40U, 40V, 40W) to each other; and

and a holding part (80) integrally provided to the insulator (30) and holding the plurality of bus bars (50N, 50U, 50V, 50W) so as to be separated from each other in the radial direction, and disposed on the inner side in the radial direction of the stator core (20).

2. The rotating electrical machine according to claim 1, wherein,

the holding portion (80) has an insulating wall (82) interposed between the plurality of bus bars (50N, 50U, 50V, 50W).

3. The rotating electrical machine according to claim 1 or 2, wherein,

the winding (41) includes lead-out portions (42, 43) extending from the coils (40U, 40V, 40W) inward in the radial direction and connected to any one of the plurality of bus bars (50N, 50U, 50V, 50W),

a slit (37) through which the lead-out portions (42, 43) pass is formed in the insulator (30).

4. The rotating electrical machine according to any one of claims 1 to 3, wherein,

the plurality of bus bars (50U, 50V, 50W) each have a winding connection portion (52) extending radially outward and connected to the winding (41),

a plurality of holding grooves (83) in which the plurality of bus bars (50U, 50V, 50W) are arranged are formed in the holding portion (80),

the holding portion (80) has an abutting portion (85) that abuts the winding connection portion (52) at a position radially outside the plurality of holding grooves (83).

5. The rotating electrical machine according to any one of claims 1 to 4, wherein,

the rotating electric machine further comprises a housing (105) for fixing the stator core (20),

the holding portion (80) is disposed between the inner rotor (2) and the outer shell (105).

6. The rotating electrical machine according to claim 5, wherein,

the bus bar (50U, 50V, 50W) has a three-phase wire connecting portion (53) extending in the axial direction and connected to a three-phase wire (60),

the three-phase wire connection (53) is fastened to the three-phase wire (60) in the radial direction.

7. The rotating electrical machine according to any one of claims 1 to 6, wherein,

the bus bar (50U, 50V, 50W) has a three-phase wire connecting portion (53) extending in the axial direction and fastened to a terminal (61) of a three-phase wire (60),

the three-phase line connecting part (53) is provided with an engaging part (54) which is engaged with the terminal (61),

the engagement portion (54) is in contact with the terminal (61) from the rotation direction of the fastening member (71).

8. The rotating electrical machine according to claim 7, wherein,

the rotating electrical machine is provided with a fastening member group (70), wherein the fastening member group (70) is provided with a first fastening member (71) and a second fastening member (72) screwed with the first fastening member (71) and fastens the three-phase line connecting part (53) and the terminal (61),

one of the first fastening member (71) and the second fastening member (72) is in contact with one of the three-phase line connecting portion (53) and the terminal (61) in the rotation direction of the other of the first fastening member (71) and the second fastening member (72).