Rotary electric machine and stator for rotary electric machines

Abstract

In a rotary electric machine, output ends of first and second three-phase windings of first and second sets included in a first group are separated from those of third and fourth three-phase windings of third and fourth sets included in a second group. Each of the first to fourth three-phase windings is inserted in the slots while being turned at one of the first and second opposing end surface sides of a stator core. Turn portions of each of the first to fourth three-phase windings at the one of the first and second opposing end surface sides of the stator core have a substantially U shape, and are so disposed as to be nonoverlapped with each other in an axial direction of the stator core.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and aspects of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings in which:

FIG. 1 is a partially axial sectional view illustrating an alternator according to an embodiment of the present invention;

FIG. 2 is a wiring diagram of a stator coil according to the embodiment of the present invention;

FIG. 3 is a supplementary wiring diagram of a first group of first and second sets of three-phase windings included in the stator coil;

FIG. 4 is a supplementary wiring diagram of a second group of first and second sets of three-phase windings included in the stator coil;

FIG. 5 is a winding diagram development of part of the stator coil according to the embodiment of the invention;

FIG. 6 is a winding diagram development of part of the stator coil according to the embodiment of the invention;

FIG. 7 is a winding diagram development of part of the stator coil according to the embodiment of the invention;

FIG. 8A is a view schematically illustrates wiring configuration of the three-phase windings of the first and second sets of the first and second groups according to the embodiment;

FIG. 8B is an enlarged view of a weld portion of the first group according to the embodiment;

FIG. 9 is an enlarged perspective view of a conductor segment constituting each of the three-phase windings of each of the first and second groups according to the embodiment;

FIG. 10 is a partially cross sectional enlarged view schematically illustrating part of the stator according to the embodiment;

FIG. 11 is a perspective view schematically illustrating a second coil end portion of the stator coil according to the embodiment;

FIG. 12 is a perspective view schematically illustrating a first coil end portion of the stator coil according to the embodiment;

FIG. 13 is a view schematically illustrating the first coil end portion of the stator coil in an axial direction of the stator core according to the embodiment;

FIG. 14A is an enlarged view schematically illustrating radially arranged turn portions of same-shaped conductor segments corresponding to first and second annular layers of a three-phase winding of one of the first and second groups of the stator coil according to the embodiment of the present invention as viewed along a circumferential direction of the stator core; and

FIG. 14B is an enlarged view schematically illustrating a pair of turn portions of small and large conductor segments of a three-phase winding of one of first and second groups of a stator coil according to a comparative example of the conventional embodiment as viewed along a circumferential direction of the stator core.

Claims

1. A rotary electric machine comprising: a rotor rotatably supported in a frame of the machine; anda stator disposed opposite to the rotor, the stator comprising: a stator core having axially opposing end surfaces and a plurality of substantially circumferentially spaced slots; and a stator coil,the stator coil comprising: a first group of first and second sets of three-phase windings mounted in the stator core, the first set including first three-phase windings each with output ends, the output ends of the first three-phase windings being connected in series to each other to form delta configuration with junctions between the first three-phase windings, the second set including second three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the first three-phase windings, anda second group of third and fourth sets of three-phase windings mounted in the stator core, the third set including third three-phase windings each with output ends, the output ends of the third three-phase windings being connected in series to each other to form delta configuration with junctions between the third three-phase windings, the fourth set including fourth three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the third three-phase windings, the output ends of the first to fourth three-phase windings and the input ends of the second and fourth windings being disposed at one of the opposing end surface sides of the stator core, the output ends of the first and second three-phase windings of the first and second sets included in the first group being separated from the output ends of the third and fourth three-phase windings of the third and fourth sets included in the second group, each of the first to fourth three-phase windings being inserted in the slots while being turned at the one of the first and second opposing end surface sides of the stator core,wherein turn portions of each of the first to fourth three-phase windings at the one of the first and second opposing end surface sides of the stator core have a substantially U shape, and are so disposed as to be nonoverlapped with each other in an axial direction of the stator core.

2. A rotary electric machine according to claim 1, wherein the turn portions of each of the first to fourth three-phase windings at the one of the first and second opposing end surface sides of the stator core are radially arranged to form a substantially multiple ring configuration.

3. A rotary electric machine according to claim 1, wherein the first group includes first weld portions formed by welding respectively the junctions of the first three-phase windings and the input ends of the second three-phase windings together, and the second group includes second weld portions formed by welding respectively the junctions of the third three-phase windings and the input ends of the fourth three-phase windings together, the first weld portions being arranged to be separated from the output ends of the second three-phase windings, the second weld portions being arranged to be separated from the output ends of the fourth three-phase windings.

4. A rotary electric machine according to claim 3, wherein each of the slots has a predetermined length in a radial direction of the stator core, and the first and second weld portions are locally arranged over radially middle portions of corresponding slots.

5. A rotary electric machine according to claim 3, wherein each of the slots has a predetermined length in a radial direction of the stator core, each of the first weld portions is composed of: one of the output ends of one of the first three-phase windings,one of the output ends of another one of the first three-phase windings, andthe input end of one of the second three-phase windings, the output and input ends constituting each of the first weld portions being circumferentially aligned and arranged over radially middle portions of corresponding slots, and each of the second weld portions is composed of:one of the output ends of one of the third three-phase windings,one of the output ends of another one of the third three-phase windings, andthe input end of one of the fourth three-phase windings, the output and input ends constituting each of the second weld portions being circumferentially aligned and arranged over radially middle portions of corresponding slots.

6. A rotary electric machine according to claim 5, wherein any one of the circumferential aligned ends of each of the first weld portions is disposed at the middle thereof, and the middle-disposed end extends substantially in the axial direction of the stator core, and any one of the circumferential aligned ends of each of the second weld portions is disposed at the middle thereof, and the middle-disposed end extends substantially in the axial direction of the stator core.

7. A rotary electric machine according to claim 3, wherein the first weld portions are substantially circumferentially aligned, each of the first weld portions is composed of: one of the output ends of one of the first three-phase windings,one of the output ends of another one of the first three-phase windings, andthe input end of one of the second three-phase windings, the ends constituting one of the first weld portions and drawn out from corresponding slots are arranged to minimize the number of intersections between the drawn-out ends of the one of the first weld portions and the ends constituting another one of the first weld portions and drawn out from corresponding slots, and each of the second weld portions is composed of:one of the output ends of one of the third three-phase windings,one of the output ends of another one of the third three-phase windings, andthe input end of one of the fourth three-phase windings, the ends constituting one of the second weld portions and drawn out from corresponding slots are arranged to minimize the number of intersections between the drawn-out ends of the one of the second weld portions and the ends constituting another one of the second weld portions and drawn out from corresponding slots.

8. A rotary electric machine according to claim 7, wherein one of the drawn-out ends of the one of the first weld portions is arranged to intersect with one of the drawn-out ends of another one of the first weld portions such that the one of the drawn-out ends of the one of the first weld portions jumps over the one of the drawn-out ends of another one of the first weld portions, and wherein one of the drawn-out ends of the one of the second weld portions is arranged to intersect with one of the drawn-out ends of another one of the second weld portions such that the one of the drawn-out ends of the one of the second weld portions jumps over the one of the drawn-out ends of another one of the second weld portions.

9. A rotary electric machine according to claim 1, wherein each of the first and second three-phase windings comprises a plurality of conductor segments each of which includes a substantially U shaped portion and substantially straight portions extending therefrom and having tip end portions, one of the tip end portions of one of the conductor segments being sequentially joined to one of the tip end portions of another one of the conductor segments to form a series-connected winding in each phase corresponding to each of the first and second three-phase windings, and each of the third and fourth three-phase windings comprises a plurality of conductor segments each of which includes a substantially U shaped portion and substantially straight portions extending therefrom and having tip end portions, one of the tip end portions of one of the conductor segments being sequentially joined to one of the tip end portions of another one of the conductor segments to form a series-connected winding in each phase corresponding to each of the third and fourth three-phase windings, and wherein the U-shaped portions of the conductor segments of each of the first to fourth three-phase windings correspond to the turn portions of each of the first to fourth three-phase windings.

10. A rotary electric machine according to claim 1, wherein the turn portions of the first to fourth three-phase windings provide a coil end of the stator coil, the output ends of the first three-phase windings and the output and input ends of the second three-phase windings are arranged at the coil end of the stator coil, and the output ends of the third three-phase windings and the output and input ends of the fourth three-phase windings are arranged at the coil end of the stator coil.

11. A rotary electric machine comprising: a rotor rotatably supported in a frame of the machine; anda stator disposed opposite to the rotor, the stator comprising: a stator core having axially opposing end surfaces and a plurality of substantially circumferentially spaced slots; and a stator coil,the stator coil comprising: a first group of first and second sets of three-phase windings mounted in the stator core, the first set including first three-phase windings each with output ends disposed respectively at circumferential positions opposite the stator core, the output ends of the first three-phase windings being connected in series to each other to form delta configuration with junctions between the first three-phase windings, the second set including second three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the first three-phase windings, anda second group of third and fourth sets of three-phase windings mounted in the stator core, the third set including third three-phase windings each with output ends disposed respectively at circumferential positions opposite the stator core, the output ends of the third three-phase windings being connected in series to each other to form delta configuration with junctions between the third three-phase windings, the fourth set including fourth three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the third three-phase windings, the output ends of the first to fourth three-phase windings and the input ends of the second and fourth windings being disposed at one of the opposing end surface sides of the stator core, each of the first to fourth three-phase windings being inserted in the slots while being turned at the one of the first and second opposing end surface sides of the stator core, the circumferential positions of the output positions of at least one of the first three-phase windings and the third three-phase windings are disposed to be included in the circumferential positions of the output ends of at least one of the second three-phase windings and the fourth three-phase windings,wherein turn portions of each of the first to fourth three-phase windings at the one of the first and second opposing end surface sides of the stator core have a substantially U shape, and are so disposed as to be nonoverlapped with each other in an axial direction of the stator core.

12. A stator comprising: a stator core having axially opposing end surfaces and a plurality of substantially circumferentially spaced slots; anda stator coil, the stator coil comprising: a first group of first and second sets of three-phase windings mounted in the stator core, the first set including first three-phase windings each with output ends, the output ends of the first three-phase windings being connected in series to each other to form delta configuration with junctions between the first three-phase windings, the second set including second three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the first three-phase windings; anda second group of third and fourth sets of three-phase windings mounted in the stator core, the third set including third three-phase windings each with output ends, the output ends of the third three-phase windings being connected in series to each other to form delta configuration with junctions between the third three-phase windings, the fourth set including fourth three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the third three-phase windings, the output ends of the first to fourth three-phase windings and the input ends of the second and fourth windings being disposed at one of the opposing end surface sides of the stator core, the output ends of the first and second three-phase windings of the first and second sets included in the first group being separated from the output ends of the third and fourth three-phase windings of the third and fourth sets included in the second group, each of the first to fourth three-phase windings being inserted in the slots while being turned at the one of the first and second opposing end surface sides of the stator core,wherein turn portions of each of the first to fourth three-phase windings at the one of the first and second opposing end surface sides of the stator core have a substantially U shape, and are so disposed as to be nonoverlapped with each other in an axial direction of the stator core.

13. A stator comprising: a stator core having axially opposing end surfaces and a plurality of substantially circumferentially spaced slots; anda stator coil, the stator coil comprising: a first group of first and second sets of three-phase windings mounted in the stator core, the first set including first three-phase windings each with output ends disposed respectively at circumferential positions opposite the stator core, the output ends of the first three-phase windings being connected in series to each other to form delta configuration with junctions between the first three-phase windings, the second set including second three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the first three-phase windings; anda second group of third and fourth sets of three-phase windings mounted in the stator core, the third set including third three-phase windings each with output ends disposed respectively at circumferential positions opposite the stator core, the output ends of the third three-phase windings being connected in series to each other to form delta configuration with junctions between the third three-phase windings, the fourth set including fourth three-phase windings having output and input ends, the input ends being respectively connected in series to the junctions of the third three-phase windings, the output ends of the first to fourth three-phase windings and the input ends of the second and fourth windings being disposed at one of the opposing end surface sides of the stator core, each of the first to fourth three-phase windings being inserted in the slots while being turned at the one of the first and second opposing end surface sides of the stator core, the circumferential positions of the output positions of at least one of the first three-phase windings and the third three-phase windings are disposed to be included in the circumferential positions of the output ends of at least one of the second three-phase windings and the fourth three-phase windings,wherein turn portions of each of the first to fourth three-phase windings at the one of the first and second opposing end surface sides of the stator core have a substantially U shape, and are so disposed as to be nonoverlapped with each other in an axial direction of the stator core.