Stator arrangement of rotary electric machine

1. A vehicle rotary electric machine including a rotor, a stator having a stator core and a stator winding mounted in said stator core and a pair of frames for supporting said rotor and said stator, wherein

said stator winding comprises a plurality of conductor segments coated with insulation film,

each of said plurality of conductor segments has straight segment ends that are circumferentially aligned and form rings at an end of said stator core and adjoining inclined portions that form coil ends at the same end of said stator core,

those of said segment ends that contact each other are welded and form joints of winding, and

each said segment ends has a bare portion that includes said joint of winding and a portion of said adjoining inclined portion to prevent heat generated while said segment ends are welded from deteriorating the insulation film.

2. The vehicle rotary electric machine according to claim 1 , wherein

said stator winding has gaps formed between said joints of winding that are aligned in said rings.

3. The vehicle rotary electric machine according to claim 1 , wherein

each of said joints of winding is coated with insulation resin after those of segment ends are welded to form circumferential undulations.

4. The vehicle rotary electric machine according to claim 1 , wherein

said conductor segments are radially aligned to form a plurality of layers in respective slots, and

a radial length of each said joint of winding after being welded is shorter than a sum of a radial length of said conductor segments ends prior to being welded.

5. The vehicle rotary electric machine according to claim 1 , wherein

said bare portion has a flat surface at a portion in contact to each other.

6. The vehicle rotary electric machine according to claim 5 , wherein

said bare portion has flat surfaces opposite said portion in contact with each other.

7. The vehicle rotary electric machine according to claim 5 , wherein

said bare portion has a flat surface on the side of said portion in contact each other.

8. The vehicle rotary electric machine according to claim 1 , wherein

said bare portion has an approximately polygonal cross-section.

9. A vehicle rotary electric machine comprising:

a rotor having a pair of cooling fans fixed opposite ends thereof;

a stator having a stator core with a plurality of slots and a stator winding mounted in said plurality of slots of said stator core, said stator winding comprising a plurality of pairs of U-shaped conductor segments coated with insulation film that are radially aligned to form a plurality of layers in respective slots; and

a pair of frames for accommodating and supporting said stator and rotor; wherein

each of said plurality of U-shaped conductor segments has straight segment ends that are circumferentially aligned and form two coaxial rings at an end of said stator core and adjoining inclined portions that form coil ends at the same end of said stator core,

those of said segment ends that contact each other are welded and form joints of winding, and

each of said segment ends has a bare surface that includes said joints of winding and a portion of said adjoining inclined portion to prevent heat generated while said segment ends are welded from deteriorating the insulation film.

10. The vehicle rotary electric machine according to claim 9 , wherein

said bare portion has a flat surface at a portion in contact to each other.

11. The vehicle rotary electric machine according to claim 10 , wherein

said bare portion has flat surfaces opposite said portion in contact with each other.

12. The vehicle rotary electric machine according to claim 10 , wherein

said bare portion has a flat surface on the side of said portion in contact each other.

13. A vehicle rotary electric machine including a rotor, a stator having a stator core and a stator winding mounted in said stator core and a pair of frames for supporting said rotor and said stator, wherein

said stator winding comprises a plurality of conductor segments coated with insulation film,

each of said plurality of conductor segments has straiaht segment ends that are circumferentially aligned and form rings at an end of said stator core and adjoining inclined portions that form coil ends at the same end of said stator core,

those of said segment ends that contact each other have a first radial length and after said segment ends are welded form joints of winding with a second radial length,

wherein said second radial length is less than said first radial length, and

each said segment ends has a bare surface that includes said joint of winding and a portion of said adjoining inclined portion to prevent heat generated while said segments ends are welded from deteriorating the insulation film.

14. The vehicle rotary electric machine according to claim 13 , wherein

said stator winding has gaps formed between said joints of winding that are aligned in said rings.

15. The vehicle rotary electric machine according to claim 13 , wherein

each of said joints of winding is coated with insulation resin after those of segment ends are welded to form circumferential undulations.

16. The vehicle rotary electric machine according to claim 13 , wherein

said conductor segments are radially aligned to form a plurality of layers in respective slots.

17. The vehicle rotary electric machine according to claim 13 , wherein said segment ends have cut out portions opposite where said segment ends contact with each other to diminish short circuiting.