Rotating electrical machine

1. A rotating electrical machine comprising:

a stator including a stator core comprising:

an annular-shaped first stack core comprising:

a plurality of first core pieces spirally stacked; and

first couplers mutually coupling the plurality of first core pieces;

an annular-shaped second stack core comprising:

a plurality of second core pieces spirally stacked; and

second couplers mutually coupling the plurality of second core pieces;

an outside shape of the second stack core being larger than an outside shape of the first stack core in a radial direction;

the first stack core and the second stack core being alternately arranged in a stack direction; and

a rotor provided on an inner peripheral side of the first stack core and the second stack core.

2. The rotating electrical machine according to claim 1 ,

wherein each of the plurality of first core pieces includes

a first main core portion provided on the inner peripheral side of the first stack core and having teeth formed on the inner peripheral side, and

a first sub core portion provided on an outer peripheral side of the first main core portion,

wherein the plurality of first core pieces are mutually coupled by the first couplers each provided at border between the first main core portion and the first sub core portion, and

wherein the first stack core comprises first dents provided on an outer peripheral face of the first stack core, the first dents being formed in positions where the first couplers are provided.

3. The rotating electrical machine according to claim 2 ,

wherein the first dents have the same shape.

4. The rotating electrical machine according to claim 2 ,

wherein the first dents are arranged in the stack direction.

5. The rotating electrical machine according to claim 2 ,

wherein the first dents neighboring in the stack direction are provided so as to be deviated in a circumferential direction of the first stack core.

6. The rotating electrical machine according to claim 5 ,

wherein the first dents neighboring in the stack direction are provided so as not to overlap each other in the stack direction.

7. The rotating electrical machine according to claim 2 ,

wherein each of the plurality of second core pieces includes

a second main core portion provided on the inner peripheral side of the second stack core and having teeth formed on the inner peripheral side, and

a second sub core portion provided on an outer peripheral side of the second main core portion,

wherein the plurality of second core pieces are mutually coupled by the second couplers each provided at border between the second main core portion and the second sub core portion, and

wherein the second stack core comprises second dents provided on an outer peripheral face of the second stack core, the second dents being formed in positions where the second couplers are provided.

8. The rotating electrical machine according to claim 7 ,

wherein the first dents are arranged in the stack direction, and

wherein the second dents are arranged in the stack direction.

9. The rotating electrical machine according to claim 7 ,

wherein the first dents have the same shape, and

wherein the second dents have the same shape.

10. The rotating electrical machine according to claim 7 ,

wherein the first dents neighboring in the stack direction are provided so as to be deviated in a circumferential direction of the first stack core, and

wherein the second dents neighboring in the stack direction are provided so as to be deviated in a circumferential direction of the second stack core.

11. The rotating electrical machine according to claim 10 ,

wherein the first dents neighboring in the stack direction are provided so as not to overlap each other in the stack direction, and

wherein the second dents neighboring in the stack direction are provided so as not to overlap each other in the stack direction.

12. The rotating electrical machine according to claim 1 ,

wherein each of the plurality of second core pieces includes

a third main core portion provided on an inner peripheral side of the second stack core and having teeth formed on the inner peripheral side, and

a third sub core portion provided on an outer peripheral side of the main core portion,

wherein the plurality of second core pieces are mutually coupled by the second couplers each provided at border between the main core portion and the sub core portion, and

wherein the second stack core comprises third dents provided on an outer peripheral face of the second stack core, the third dents being formed in positions where the second couplers are provided.

13. The rotating electrical machine according to claim 12 ,

wherein the third dents are arranged in the stack direction.

14. The rotating electrical machine according to claim 12 ,

wherein the third dents have the same shape.

15. The rotating electrical machine according to claim 12 ,

wherein the third dents neighboring in the stack direction are provided so as to be deviated in a circumferential direction of the second stack core.

16. The rotating electrical machine according to claim 15 ,

wherein the third dents neighboring in the stack direction are provided so as not to overlap each other in the stack direction.

17. A rotating electrical machine comprising:

a stator including a stator core comprising:

an annular-shaped first stack core comprising:

a plurality of first core pieces spirally stacked; and

first couplers mutually coupling the plurality of first core pieces;

an annular-shaped second stack core comprising:

a plurality of second core pieces spirally stacked; and

second couplers mutually coupling the plurality of second core pieces;

an outside shape of the second stack core being larger than an outside shape of the first stack core in a radial direction; and

a rotor provided on an inner peripheral side of the first and second stack cores.