Bus ring

Abstract

A bus ring (18) is provided with an inner ring part (38), an outer ring part (40), and a bridge part (32) that connects the inner ring part (38) and the outer ring part (40). The inner ring part (38) is provided with: first insertion grooves (42) (a U-phase insertion groove (42u), a V-phase insertion groove (42v), a W-phase insertion groove (42w)) which are provided on a first ring end surface (381) and into which a U-phase bus bar (36u), a V-phase bus bar (36v), and a W-phase bus bar (36w) are inserted; and a second insertion groove (44) which is provided on a second ring end surface (382) and into which the neutral wire bus bar (48) is inserted. When viewed in the axial direction of the bus ring (18), the second insertion groove (44) and the bridge part (32) overlap each other.

Description

Bus Ring

[0001] The present invention relates to a bus ring for a rotating electrical machine.

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development of electrification technologies has been conducted to reduce CO2 emissions and improve energy efficiency in vehicles. International Publication No. 2023 / 190308 discloses a rotating electric machine having a bus ring disposed on the inner periphery of a stator. The bus ring includes an inner ring provided with terminal portions, an outer ring engaged with multiple insulating members, and a bridge portion connecting the inner ring and the outer ring.

[0003] Japanese Patent Application Laid-Open Publication No. 2007-325482 discloses a rotating electric machine having a bus bar on the upper side of a stator, and the upper surface of the bus bar has three insertion grooves for inserting three-phase conductive members. The three insertion grooves are arranged in parallel and spaced apart from each other in the radial direction of the bus bar.

[0004] However, busbars with bridge portions such as those disclosed in International Publication No. 2023 / 190308 (related to electrification technology) have the problem of becoming larger in the radial direction.In the busbar disclosed in Japanese Patent Application Laid-Open No. 2007-325482 (related to electrification technology), insertion grooves for inserting conductive members are arranged side by side in the radial direction, and if an insertion groove for inserting a neutral conductor is further added, the four insertion grooves result in a problem of the busbar becoming larger in the radial direction.

[0005] The present invention aims to solve the above-mentioned problems.

[0006] One aspect of the present invention relates to a rotating electric machine including a rotor having a magnet, a cylindrical stator core surrounding the rotor, and three-phase coils wound around the stator core. The bus ring has an annular shape including three bus bars connected to the three-phase coils, and includes an inner ring portion, an outer ring portion arranged radially outward of the inner ring portion, and a bridge portion connecting the inner ring portion and the outer ring portion. The inner ring portion includes a first ring end face provided on one axial side of the bus ring, a second ring end face provided on the other axial side of the bus ring, three first insertion grooves provided on the first ring end face into which the three bus bars are respectively inserted, and a second insertion groove provided on the second ring end face into which a neutral wire is inserted. When viewed from the axial direction of the bus ring, the second insertion grooves overlap with the bridge portion.

[0007] According to the present invention, the second insertion groove opens in the opposite direction to the first insertion groove in the inner ring portion of the bus ring, and the second insertion groove and the bridge portion are arranged so as to overlap when viewed from the axial direction. This effectively prevents the bus ring from becoming larger in diameter in the radial direction while suppressing a decrease in strength of the bridge portion due to the second insertion groove.

[0008] FIG. 1 is a plan view of a rotating electric machine according to an embodiment of the present invention. FIG. 2 is an enlarged plan view of the rotating electric machine shown in FIG. 1. FIG. 3 is an enlarged plan view showing an engagement structure of the rotating electric machine. FIG. 4 is an enlarged side view of the rotating electric machine shown in FIG. 1. FIG. 5 is an external perspective view of a bus ring. FIG. 6 is a plan view of the bus ring shown in FIG. 5, viewed from one axial side. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is a plan view of the bus ring shown in FIG. 5, viewed from the other axial side. FIG. 9 is an enlarged perspective view showing the engagement structure of the rotating electric machine.

[0009] 1, a rotating electric machine 10 according to this embodiment is, for example, an electric motor mounted on a vehicle (not shown) to provide driving force to drive wheels of the vehicle. The rotating electric machine 10 may also function as an electric motor / generator. The rotating electric machine 10 may also function as a generator. Note that the rotating electric machine 10 is not limited to being mounted on a vehicle.

[0010] The rotating electric machine 10 includes a rotor 12 having a magnet 121 , a cylindrical stator 14 surrounding the rotor 12 , and an annular bus ring 18 .

[0011] The rotor 12 has a rotor body 122 and a rotating shaft 123. A plurality of magnets 121 are provided on the outer periphery of the rotor body 122. The magnets 121 are arranged at a predetermined distance from one another along the circumferential direction of the rotor body 122. The rotating shaft 123 is press-fitted into the center of the rotor body 122 along the axial direction of the rotor body 122. This connects the rotor body 122 and the rotating shaft 123 and causes them to rotate integrally. In a plan view of the rotating electric machine 10, when the coil 16 is energized, the rotor 12 rotates in a first direction R1 during forward movement. In other words, the forward rotation direction of the rotor 12 is the first direction R1.

[0012] The stator 14 includes a stator core 14A and a plurality of coils 16. The stator core 14A includes an annular portion 141, a winding portion 142, and a flange portion 143. The stator core 14A includes split cores 14B formed by stacking a plurality of steel plates (not shown) in the axial direction and splitting them in the circumferential direction. The stator core 14A is configured by connecting the split cores 14B to each other in the circumferential direction via connecting portions 144. Note that the stator core 14A is not limited to a configuration in which a plurality of split cores 14B are connected in the circumferential direction. For example, the stator core 14A may be configured as a single piece in the circumferential direction.

[0013] The annular portion 141 is formed in a circular ring shape. The annular portion 141 is composed of a plurality of split cores 14B connected to one another. The annular portion 141 has mounting holes 20 that penetrate the steel plate in the thickness direction. Fastening bolts 22 for fastening the stator core 14A (stator 14) to a housing (not shown) are inserted into the mounting holes 20 (see FIG. 2). The fastening bolts 22 are screwed into the housing, thereby fixing the stator core 14A to the housing.

[0014] 2, the winding portion 142 is provided radially inward of the annular portion 141, and the coil 16 is wound around the winding portion 142. The winding portion 142 protrudes radially inward from the inner circumferential surface of the annular portion 141. A winding portion 142 is provided on each split core 14B. That is, there are multiple winding portions 142.

[0015] As shown in FIG. 3 , the flange 143 is provided at the radially inner end 142 a of each winding portion 142. The flange 143 protrudes from the radially inner end 142 a of each winding portion 142 in the circumferential direction of the stator core 14A. The flange 143 includes a first flange 241 and a second flange 242. The first flange 241 is provided on the winding portion 142 on the first direction R1 side. That is, the first flange 241 is provided on the winding portion 142 on the side facing the forward rotation direction of the rotor 12 when the coil 16 is energized. The second flange 242 is provided on the winding portion 142 on the second direction R2 side, which is opposite to the first direction R1. The rotor 12 is disposed inside the flange 143 of the stator core 14A (see FIG. 1 ).

[0016] As shown in FIG. 4 , the stator core 14A further includes a first end face 261, a second end face 262, and a side face 263. The first end face 261 is provided on one axial side of the stator core 14A. The second end face 262 is provided on the other axial side of the stator core 14A. Each of the first end face 261 and the second end face 262 is a plane that intersects with the axial direction of the stator core 14A. The side face 263 intersects with the first end face 261 and the second end face 262 and faces each other in the circumferential direction of the stator core 14A. The side face 263 extends along the axial direction of the stator core 14A.

[0017] The coil 16 is wound around the winding portion 142 of the stator core 14A multiple times. As shown in FIG. 2 , in a plan view of the rotating electric machine 10, the coil 16 is disposed between the annular portion 141 and the flange portion 143 of the stator core 14A. The wound coil 16 has an inner circumferential end 281 and an outer circumferential end 282. The inner circumferential end 281 of the coil 16 is disposed at the radially inner end 142a of the winding portion 142 and faces the flange portion 143. The outer circumferential end 282 of the coil 16 is disposed at the radially outer end of the winding portion 142 and faces the inner circumferential portion of the annular portion 141. The stator 14 is formed by winding multiple coils 16 around the stator core 14A. The multiple coils 16 are wound around the multiple winding portions 142 using a concentrated winding method.

[0018] Coil 16 has a starting end 16s where winding begins around winding portion 142, and a terminal end 16e where winding ends around winding portion 142. Starting end 16s and terminal end 16e each extend radially inward from coil 16 toward stator core 14A. The multiple coils 16 include a U-phase coil, a V-phase coil, and a W-phase coil.

[0019] 1, bus ring 18 is formed in an annular shape from a resin material. Bus ring 18 is provided to connect three-phase coils 16. Bus ring 18 is provided at one axial end of stator core 14A (see FIG. 4).

[0020] As shown in FIG. 5 , the bus ring 18 includes a ring main body 30, a bridge portion 32, multiple protrusions 34, and three bus bars 36. Each bus bar 36 is a conductor made of a metal material and is connected to a respective one of the three-phase (U-phase, V-phase, and W-phase) coils 16 (see FIG. 1 ). Each bus bar 36 includes a main body 361, a terminal portion 362 provided on the main body 361 to which the coil 16 is connected, and a connection portion 363 to which a power line (not shown) is connected. As shown in FIG. 6 , when viewed in the axial direction of the bus ring 18, the main body 361 is formed in an arc shape. As shown in FIG. 5 , the terminal portion 362 protrudes axially from one axial end of the bus bar 36 and has a U-shape that opens in the circumferential direction of the bus ring 18. The starting end 16 s of each coil 16 is connected to the terminal portion 362, and the ending end 16 e is connected to a neutral point 482 of the neutral bus bar 48 (see FIG. 2 ). The connection portion 363 extends axially from the axial end of the main body 361 and then bends radially inward. The connection portion 363 protrudes radially inward beyond the ring main body 30. Hereinafter, the bus bar 36 to which the U-phase coil 16 is connected will be referred to as a U-phase bus bar 36u. The bus bar 36 to which the V-phase coil 16 is connected will be referred to as a V-phase bus bar 36v. The bus bar 36 to which the W-phase coil 16 is connected will be referred to as a W-phase bus bar 36w.

[0021] The ring main body 30 includes an inner ring portion 38 and an outer ring portion 40. As shown in FIG. 6 , the inner ring portion 38 is formed in an annular shape. As shown in FIG. 7 , the inner ring portion 38 includes a first ring end face 381 and a second ring end face 382. The first ring end face 381 is an annular surface provided on one axial side of the bus ring 18. The second ring end face 382 is an annular surface provided on the other axial side of the bus ring 18. Each of the first ring end face 381 and the second ring end face 382 is a flat surface extending in a direction perpendicular to the axial direction of the bus ring 18. The first ring end face 381 and the second ring end face 382 are parallel to each other and spaced apart in the axial direction of the bus ring 18. When the bus ring 18 is attached to the stator 14 (stator core 14A), the second ring end face 382 is the surface that faces the first end face 261 of the stator core 14A.

[0022] The inner ring portion 38 further includes three first insertion grooves 42 and a second insertion groove 44. The three first insertion grooves 42 are provided in the first ring end face 381. Three bus bars 36 (a U-phase bus bar 36u, a V-phase bus bar 36v, and a W-phase bus bar 36w) are inserted into the three first insertion grooves 42, respectively. As shown in FIG. 6 , when viewed in the axial direction of the bus ring 18, the three first insertion grooves 42 are spaced apart from one another in the radial direction. As shown in FIG. 7 , the first insertion grooves 42 open to the first ring end face 381 and are recessed toward the second ring end face 382. The first insertion grooves 42 have stopper portions 461. The stopper portions 461 are provided at the openings of the first insertion grooves 42. The stopper portions 461 protrude from the radial inner walls of the first insertion grooves 42 in directions approaching each other. The stopper portion 461 narrows the opening of the first insertion groove 42 .

[0023] Hereinafter, of the three first insertion grooves 42, the first insertion groove 42 into which the U-phase bus bar 36u is inserted will be referred to as the "U-phase insertion groove 42u," the first insertion groove 42 into which the V-phase bus bar 36v is inserted will be referred to as the "V-phase insertion groove 42v," and the first insertion groove 42 into which the W-phase bus bar 36w is inserted will be referred to as the "W-phase insertion groove 42w." As shown in FIG. 2 , on the first ring end surface 381 of the inner ring portion 38, the first insertion grooves 42 are such that the U-phase insertion groove 42u is located furthest inward in the radial direction, the V-phase insertion groove 42v is located radially outward from the U-phase insertion groove 42u, and the W-phase insertion groove 42w is located further radially outward from the V-phase insertion groove 42v. That is, the W-phase insertion groove 42w is located furthest outward in the radial direction.

[0024] As shown in Fig. 7 , the main body 361 of the U-phase bus bar 36u is inserted into the U-phase insertion groove 42u. The main body 361 of the V-phase bus bar 36v is inserted into the V-phase insertion groove 42v. The main body 361 of the W-phase bus bar 36w is inserted into the W-phase insertion groove 42w. The first insertion grooves 42 support the U-phase bus bar 36u, the V-phase bus bar 36v, and the W-phase bus bar 36w while spaced apart from one another in the radial direction. Stopper portions 461 prevent the main body portions 361 of the U-phase bus bar 36u, the V-phase bus bar 36v, and the W-phase bus bar 36w from coming out of the first insertion grooves 42.

[0025] As shown in FIG. 8 , the second insertion grooves 44 are provided in the second ring end face 382. In the axial direction of the bus ring 18, the opening direction of the three first insertion grooves 42 and the opening direction of the second insertion groove 44 are opposite to each other. A neutral bus bar 48 is inserted into the second insertion groove 44. The neutral bus bar 48 includes a main body 481 and a neutral point 482 provided in the main body 481. When viewed in the axial direction of the bus ring 18, the main body 481 is formed in an arc shape. As shown in FIG. 7 , the neutral point 482 protrudes in the axial direction from one axial end of the neutral bus bar 48. The neutral point 482 is U-shaped and opens in the circumferential direction of the bus ring 18 (see FIG. 6 ). 8 , when viewed in the axial direction of the bus ring 18, the second insertion groove 44 is disposed radially outward from the first insertion groove 42 (W-phase insertion groove 42 w) that is located radially outermost among the plurality of first insertion grooves 42. The second insertion groove 44 opens to the second ring end face 382 and is recessed toward the first ring end face 381.

[0026] As shown in Figure 7, the second insertion groove 44 has a stopper portion 462. The stopper portion 462 is provided at the opening of the second insertion groove 44. The stopper portions 462 protrude from the radial inner wall of the second insertion groove 44 in directions approaching each other. The stopper portion 462 narrows the opening of the second insertion groove 44. The main body portion 481 of the neutral bus bar 48 is inserted into the second insertion groove 44. The stopper portion 462 prevents the neutral bus bar 48 from coming out of the second insertion groove 44.

[0027] 6 , the outer ring portion 40 is formed in an annular shape and is disposed radially outward of the inner ring portion 38. The inner ring portion 38 and the outer ring portion 40 are disposed coaxially with the central axis of the bus ring 18 as the center.

[0028] The bridge portion 32 connects the inner ring portion 38 and the outer ring portion 40. The bridge portion 32 includes an axial bridge portion 321 and a radial bridge portion 322. As shown in FIG. 7 , the axial bridge portion 321 protrudes in the axial direction from the first ring end surface 381 of the inner ring portion 38. The axial bridge portion 321 protrudes in a direction away from the first ring end surface 381.

[0029] The radial bridge portion 322 extends from the axial bridge portion 321 toward the outer ring portion 40. That is, the radial bridge portion 322 extends radially outward from the axial bridge portion 321. The radial bridge portion 322 extends parallel to a direction perpendicular to the axial direction of the bus ring 18. The first ring end face 381 and the radial bridge portion 322 are spaced apart in the axial direction of the bus ring 18. A space 50 is defined between the first ring end face 381 and the radial bridge portion 322 in the axial direction of the bus ring 18.

[0030] As shown in FIG. 8 , when viewed in the axial direction of the bus ring 18 , the second insertion grooves 44 and the axial bridge portions 321 of the bridge portions 32 overlap with each other.

[0031] The multiple protrusions 34 are provided on the radially outer end of the outer ring portion 40. The multiple protrusions 34 are provided spaced apart from one another along the circumferential direction of the outer ring portion 40 (ring main body portion 30). The multiple protrusions 34 protrude radially outward from the radially outer end of the outer ring portion 40. The multiple protrusions 34 extend from the outer ring portion 40 in the axial direction of the bus ring 18 (see FIG. 5). As shown in FIG. 3, each protrusion 34 has a radial end 52 that is provided radially outward from the radially inner end 142a of the stator core 14A. The radial end 52 of the protrusion 34 abuts against the inner circumferential end 281 of the coil 16 wound around the winding portion 142. The radial end 52 abuts against the radially inner side of the inner circumferential end 281 of the coil 16. As shown in FIG. 5, the protrusion 34 has a first protrusion 341 and a second protrusion 342. The first protruding portion 341 and the second protruding portion 342 are spaced apart from each other in the circumferential direction of the bus ring 18. Each protruding portion 34 is arranged in pairs, with the first protruding portion 341 and the second protruding portion 342 adjacent to each other in the circumferential direction.

[0032] 4 , the first protrusion 341 extends from the outer ring portion 40 of the ring main body 30 in the axial direction of the bus ring 18. The first protrusion 341 has a first radial extension 541 (hereinafter also referred to as a “first leg portion 561”) and a first circumferential extension 581.

[0033] 9 , the first radial extending portion 541 extends radially outward from the outer ring portion 40. The first radial extending portion 541 is linear in the radially outward direction. The radial end portion 521 of the first radial extending portion 541 includes a first bent portion 601 that is bent toward the stator core 14A side relative to the first radial extending portion 541.

[0034] As shown in FIG. 3 , the tip of the first bent portion 601 includes a first circumferential extending portion 581. The first circumferential extending portion 581 extends from the first radial extending portion 541 (first bent portion 601) in the circumferential direction of the stator core 14A. The extension direction of the first circumferential extending portion 581 relative to the first radial extending portion 541 is a second direction R2, which is the opposite direction to the forward rotation direction (first direction R1) of the rotor 12. Note that the extension direction of the first circumferential extending portion 581 is not limited to the second direction R2. For example, the extension direction of the first circumferential extending portion 581 may be the first direction R1.

[0035] The tip of the first protrusion 341 has a first circumferential extending portion 581, which faces the side surface 263 in the circumferential direction of the stator core 14A. The first circumferential extending portion 581 of the first protrusion 341 abuts against a first portion 621 of the stator core 14A. The first portion 621 is the first flange 241 of the stator core 14A. That is, the first protrusion 341 abuts against the first flange 241 of the stator core 14A. As shown in FIG. 4 , the starting end 16 s of the coil 16 abuts against the first protrusion 341. The starting end 16 s of the coil 16 is supported by the first protrusion 341. As shown in FIG. 2 , the first radial extending portion 541 abuts against an inner circumferential end 281 of the coil 16 wound around the winding portion 142. That is, the radial end 521 of the first protrusion 341 abuts against the inner circumferential end 281 of the coil 16 .

[0036] The first circumferential extending portion 581 has a first coil holding portion 641. The first coil holding portion 641 holds the starting end 16s of the coil 16.

[0037] The second protrusion 342 extends from the outer ring portion 40 in the axial direction of the bus ring 18. The second protrusion 342 has a second radial extension 542 (hereinafter also referred to as a “second leg portion 562”) and a second circumferential extension 582.

[0038] As shown in Fig. 3, the second radial extending portion 542 extends radially outward from the outer ring portion 40. The second radial extending portion 542 is linear in the radially outward direction. As shown in Fig. 4, the radial end portion 522 of the second radial extending portion 542 is provided with a second bent portion 602 that is bent toward the stator core 14A side with respect to the second radial extending portion 542.

[0039] The tip of the second bent portion 602 includes a second circumferential extending portion 582. The second circumferential extending portion 582 extends from the second radial extending portion 542 (second bent portion 602) in the circumferential direction of the stator core 14A. The extension direction of the second circumferential extending portion 582 relative to the second radial extending portion 542 is a second direction R2, which is opposite to the forward rotation direction (first direction R1) of the rotor 12. Note that the extension direction of the second circumferential extending portion 582 is not limited to the second direction R2. For example, the extension direction of the second circumferential extending portion 582 may be the first direction R1. In this case, the extension direction of the first circumferential extending portion 581 is also the first direction R1. The first circumferential extending portion 581 and the second circumferential extending portion 582 are spaced apart from each other in the circumferential direction of the outer ring portion 40.

[0040] The tip of the second protrusion 342 has a second circumferential extending portion 582, which faces the first end face 261 in the axial direction of the stator core 14A. The second circumferential extending portion 582 of the second protrusion 342 abuts against a second portion 622 of the stator core 14A that is different from the first portion 621. The second portion 622 is the first end face 261 of the stator core 14A. That is, the second protrusion 342 abuts against the first end face 261 of the stator core 14A. The second radial extending portion 542 abuts against the inner circumferential end 281 of the coil 16 wound around the winding portion 142. That is, the radial end portion 522 of the second protrusion 342 abuts against the inner circumferential end 281 of the coil 16 (see FIG. 3 ).

[0041] 4, the second circumferential extending portion 582 has a second coil holding portion 642. The second coil holding portion 642 holds the terminal end 16e of the coil 16.

[0042] As shown in FIG. 3, the rotating electrical machine 10 further includes an engagement structure 66 that engages the stator core 14A and the bus ring 18 with each other.

[0043] The engagement structure 66 has a ring-side engagement portion 68 provided on the bus ring 18 and a stator-side engagement portion 70 provided on the stator core 14A that engages with the ring-side engagement portion 68.

[0044] As shown in FIG. 9 , the ring-side engaging portion 68 is provided on the first protruding portion 341 of the bus ring 18 and engages with the stator core 14A. The ring-side engaging portion 68 engages with the first flange portion 241 of the stator core 14A. The ring-side engaging portion 68 is provided on the first bent portion 601 of the first protruding portion 341. The ring-side engaging portion 68 is provided on the first circumferential extending portion 581 of the first protruding portion 341. The first circumferential extending portion 581 is disposed radially outward from the first flange portion 241 of the stator core 14A. The ring-side engaging portion 68 has a recess 72 extending in the axial direction of the bus ring 18. In a plan view of the rotating electric machine 10, the recess 72 is formed on the inner surface of the first circumferential extending portion 581. The recess 72 is recessed from the inner surface of the first circumferential extending portion 581 radially outward from the bus ring 18.

[0045] The ring side engaging portion 68 is further provided on the second protruding portion 342 and abuts against the stator core 14A. The ring side engaging portion 68 abuts against the first end face 261 of the stator core 14A. The ring side engaging portion 68 is provided on the second bent portion 602 of the second protruding portion 342. The ring side engaging portion 68 is provided on the second circumferential extending portion 582 of the second protruding portion 342. The second circumferential extending portion 582 is disposed to face the first end face 261 in the axial direction of the stator core 14A. The second circumferential extending portion 582 abuts against the first end face 261 of the stator core 14A, thereby engaging with each other.

[0046] As shown in FIG. 3 , the stator-side engaging portion 70 is provided on the first flange 241 of the stator core 14A and engages with the bus ring 18. The stator-side engaging portion 70 engages with the first protruding portion 341 of the bus ring 18. The stator-side engaging portion 70 is disposed radially inward of a portion of the first radially extending portion 541 of the bus ring 18. The stator-side engaging portion 70 has a protruding portion 74 that extends in the axial direction of the stator core 14A and is inserted into the recessed portion 72. The protruding portion 74 is provided on the outer surface of the first flange 241 and protrudes radially outward from the outer surface. As shown in FIG. 9 , the protruding portion 74 extends in the axial direction of the stator core 14A.

[0047] Next, a description will be given of the operation of the rotating electric machine 10. Electric power is supplied from a power source (not shown) to the connection portions 363 of the U-phase bus bar 36u, the V-phase bus bar 36v, and the W-phase bus bar 36w, thereby energizing the U-phase bus bar 36u, the V-phase bus bar 36v, and the W-phase bus bar 36w. When the U-phase bus bar 36u, the V-phase bus bar 36v, and the W-phase bus bar 36w are energized, the coils 16 are excited to generate a rotating magnetic field, and the rotor 12, to which the magnets 121 serving as magnetic poles are attached, is rotated in the first direction R1 inside the stator core 14A.

[0048] This embodiment has the following advantages.

[0049] As shown in Fig. 5 , the bus ring 18 includes an inner ring portion 38, an outer ring portion 40, and a bridge portion 32 connecting the inner ring portion 38 and the outer ring portion 40. As shown in Fig. 6 , the inner ring portion 38 includes a first ring end face 381, a second ring end face 382, ​​three first insertion grooves 42 (U-phase insertion groove 42u, V-phase insertion groove 42v, W-phase insertion groove 42w) provided on the first ring end face 381 and into which three bus bars (U-phase bus bar 36u, V-phase bus bar 36v, W-phase bus bar 36w) are respectively inserted, and a second insertion groove 44 provided on the second ring end face 382 and into which a neutral conductor (neutral conductor bus bar 48) is inserted. As shown in Fig. 8 , when viewed in the axial direction of the bus ring 18, the second insertion groove 44 and the bridge portion 32 overlap.

[0050] As a result, the second insertion groove 44 opens in the opposite direction to the first insertion groove 42 in the inner ring portion 38, and the second insertion groove 44 and the bridge portion 32 are arranged so that they overlap when viewed from the axial direction, thereby effectively preventing the bus ring 18 from becoming larger in diameter in the radial direction while suppressing a decrease in strength of the bridge portion 32 due to the second insertion groove 44.

[0051] The bridge portions 32 and the second insertion grooves 44 are disposed radially outward from the three first insertion grooves 42 (the U-phase insertion groove 42u, the V-phase insertion groove 42v, and the W-phase insertion groove 42w). By disposing the bridge portions 32 and the second insertion grooves 44 disposed radially outward so as to overlap in the axial direction, it is possible to effectively prevent the bus ring 18 from becoming larger radially outward.

[0052] As shown in Fig. 5 , the bridge portion 32 includes an axial bridge portion 321 that protrudes in the axial direction from the first ring end face 381, and a radial bridge portion 322 that extends from the axial bridge portion 321 toward the outer ring portion 40. The first ring end face 381 and the radial bridge portion 322 are spaced apart in the axial direction of the bus ring 18. As a result, as shown in Fig. 7 , the first ring end face 381 and the radial bridge portion 322 of the bus ring 18 are spaced apart in the axial direction, which ensures space for connecting the coil 16 to the three-phase bus bars attached to the first ring end face 381. This improves the workability of connecting the coil 16 to the bus bars 36.

[0053] 3 , the radially outer end of the outer ring portion 40 has circumferential extending portions (first circumferential extending portion 581 and second circumferential extending portion 582) that extend in the circumferential direction of the outer ring portion 40, and the circumferential extending portions are formed with coil holding portions (first coil holding portion 641 and second coil holding portion 642) that hold the ends of the coils 16 wound around the stator core 14A. This allows the ends of the coils 16 to be held by the bus ring 18, so that the ends can be effectively guided and connected to the terminal portions 362 of the bus bars (U-phase bus bar 36u, V-phase bus bar 36v, W-phase bus bar 36w, and neutral bus bar 48) without damaging the coils 16.

[0054] The circumferential extending portion of the bus ring 18 includes a first circumferential extending portion 581 and a second circumferential extending portion 582 that are spaced apart from each other in the circumferential direction of the outer ring portion 40. A first coil holding portion 641 of the first circumferential extending portion 581 holds the starting end 16s of the coil 16, and a second coil holding portion 642 of the second circumferential extending portion 582 holds the ending end 16e of the coil 16. As a result, the first circumferential extending portion 581 and the second circumferential extending portion 582 can effectively prevent contact between the starting end 16s and the ending end 16e of the coil 16 and the stator core 14A, thereby preventing damage to the coil 16 due to contact with the stator core 14A.

[0055] In addition to the above disclosure, the following additional notes are disclosed.

[0056] (Supplementary Note 1) In a rotating electric machine (10) including a rotor (12) having a magnet (121), a cylindrical stator core (14A) surrounding the rotor, and three-phase coils (16) wound around the stator core, a bus ring (18) is an annular bus bar including three bus bars (36, 36u, 36v, 36w) connected to the three-phase coils, and includes an inner ring portion (38), an outer ring portion (40) disposed radially outward of the inner ring portion, and a bridge portion (32) connecting the inner ring portion and the outer ring portion. ), and the inner ring portion includes a first ring end face (381) provided on one axial side of the bus ring, a second ring end face (382) provided on the other axial side of the bus ring, three first insertion grooves (42, 42u, 42v, 42w) provided on the first ring end face and into which the three bus bars are respectively inserted, and a second insertion groove (44) provided on the second ring end face and into which a neutral conductor (48) is inserted, and when viewed from the axial direction of the bus ring, the second insertion groove and the bridge portion overlap.

[0057] With this configuration, the second insertion groove opens in the opposite direction to the first insertion groove in the inner ring portion, and the second insertion groove and the bridge portion are arranged so as to overlap when viewed from the axial direction. This effectively prevents the bus ring from becoming larger in diameter in the radial direction while suppressing a decrease in strength of the bridge portion due to the second insertion groove.

[0058] (Supplementary Note 2) In the bus ring described in Supplementary Note 1, the bridge portion and the second insertion groove may be disposed radially outward from the three first insertion grooves. With this configuration, by disposing the bridge portion and the second insertion groove disposed radially outward so as to overlap in the axial direction, it is possible to effectively prevent the bus ring from becoming large in the radial direction.

[0059] (Supplementary Note 3) In the bus ring described in Supplementary Note 1 or 2, the bridge portion may include an axial bridge portion (321) protruding from the first ring end face in the axial direction and a radial bridge portion (322) extending from the axial bridge portion toward the outer ring portion, and the first ring end face and the radial bridge portion may be spaced apart in the axial direction of the bus ring. With this configuration, the first ring end face and the radial bridge portion of the bus ring are spaced apart in the axial direction, which ensures space for connecting coils to three-phase bus bars attached to the first ring end face. This improves the workability of connecting coils to bus bars.

[0060] (Supplementary Note 4) In the bus ring according to any one of Supplementary Notes 1 to 3, a radially outer end of the outer ring portion may have a circumferential extending portion (581, 582) extending in the circumferential direction of the outer ring portion, and the circumferential extending portion may have a coil holding portion (641, 642) formed thereon to hold an end of the coil wound around the stator core. With this configuration, the end of the coil can be held by the bus ring, and the end can be effectively guided and connected to the terminal portion of the bus bar without damaging the coil.

[0061] (Supplementary Note 5) In the bus ring described in Supplementary Note 4, the circumferential extending portion may include a first circumferential extending portion (581) and a second circumferential extending portion (582) spaced apart from each other in the circumferential direction of the outer ring portion, wherein the coil holding portion (641) of the first circumferential extending portion may hold a starting end (16s) where the coil begins to be wound around the stator core, and the coil holding portion (642) of the second circumferential extending portion may hold a terminal end (16e) where the coil ends to be wound around the stator core. With this configuration, the first circumferential extending portion and the second circumferential extending portion can effectively prevent contact between the starting end and the terminal end of the coil and the stator core, thereby preventing damage to the coil due to contact with the stator core.

[0062] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

[0063] REFERENCE SIGNS LIST 10... Rotating electric machine 12... Rotor 14A... Stator core 16... Coil 18... Bus ring 30... Ring main body 34... Projection 52... Radial end 141... Annular portion 142... Winding portion 281... Inner peripheral end

Claims

1. A rotating electric machine (10) including a rotor (12) having a magnet (121), a cylindrical stator core (14A) surrounding the rotor (12), and a three-phase coil (16) wound around the stator core (14A), wherein an annular bus ring (18) includes three bus bars (36, 36u, 36v, 36w) connected to the three-phase coils (16), the bus ring (18) comprising an inner ring portion (38), an outer ring portion (40) disposed radially outward of the inner ring portion (38), and a bridge portion (32) connecting the inner ring portion (38) and the outer ring portion (40), the inner ring portion (38) comprising: a first ring end face (381) provided on one axial side of the bus ring (18), and a second ring end face (382) provided on the other axial side of the bus ring (18), a first ring end face (381) provided with three first insertion grooves (42, 42u, 42v, 42w) into which the three bus bars (36, 36u, 36v, 36w) are inserted, and a second insertion groove (44) provided in the second ring end face (382) into which a neutral wire (48) is inserted, wherein the second insertion grooves (44) overlap the bridge portion (32) when viewed in the axial direction of the bus ring (18).

2. A bus ring (18) according to claim 1, wherein the bridge portion (32) and the second insertion groove (44) are disposed radially outward from the three first insertion grooves (42, 42u, 42v, 42w).

3. A bus ring (18) according to claim 1 or 2, wherein the bridge portion (32) has an axial bridge portion (321) protruding in the axial direction from the first ring end face (381), and a radial bridge portion (322) extending from the axial bridge portion (321) toward the outer ring portion (40), and wherein the first ring end face (381) and the radial bridge portion (322) are spaced apart in the axial direction of the bus ring (18).

4. A bus ring (18) according to claim 3, wherein the radially outer end of the outer ring portion (40) has circumferential extension portions (581, 582) extending in the circumferential direction of the outer ring portion (40), and the circumferential extension portions (581, 582) are formed with coil holding portions (641, 642) that hold the ends of the coils (16) wound around the stator core (14A).

5. A bus ring (18) according to claim 4, wherein the circumferential extending portions (581, 582) comprise a first circumferential extending portion (581) and a second circumferential extending portion (582) spaced apart from each other in the circumferential direction of the outer ring portion (40), the coil holding portion (641) of the first circumferential extending portion (581) holds a starting end portion (16s) at which the coil (16) begins to be wound around the stator core (14A), and the coil holding portion (642) of the second circumferential extending portion (582) holds a terminal end portion (16e) at which the coil (16) ends to be wound around the stator core (14A).

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