Axial gap motor rotor and axial gap motor

1. An axial gap motor rotor opposing a stator in an axial direction, the axial gap motor rotor comprising:

a rotor core; and

a magnet arranged on the rotor core, wherein the magnet is configured so that one axial end includes magnetic poles that alternately change in a circumferential direction, the magnetic poles being located at two axial ends of the rotor core and coupled together in the circumferential direction respectively at the two axial ends, wherein

the rotor core includes a base, which is located at a center in a radial direction, and radial extensions, which are extended from the base outward in the radial direction and arranged in the circumferential direction,

the magnet is configured to at least partially overlap the radial extensions in the axial direction, and

the radial extensions are located to include a boundary of adjacent ones of the magnetic poles in the circumferential direction.

2. The axial gap motor rotor according to claim 1 , wherein each of the radial extensions includes a thin portion that is thinner in the axial direction than other portions of the rotor core.

3. The axial gap motor rotor according to claim 1 , wherein

the rotor core includes an outer circumferential portion located at a radially outer side of the radial extensions and extended in the circumferential direction from the radial extensions, and

the rotor core includes a magnetic path interruption portion configured to interrupt a magnetic path arranged in at least either one of the radial extensions and the outer circumferential portion.

4. The axial gap motor rotor according to claim 2 , wherein

the rotor core includes an outer circumferential portion located at a radially outer side of the radial extensions and extended in the circumferential direction from the radial extensions, and

the rotor core includes a magnetic path interruption portion configured to interrupt a magnetic path arranged in at least either one of the radial extensions and the outer circumferential portion.

5. The axial gap motor rotor according to claim 4 , wherein

the outer circumferential portion is thicker in the axial direction than the thin portion, and

the outer circumferential portion abuts against the magnet in the radial direction.

6. An axial gap motor comprising:

the axial gap motor rotor according to claim 1 ; and

the stator opposing the axial gap motor rotor in the axial direction.

7. The axial gap motor according to claim 6 , wherein

the stator is arranged at two axial sides of the axial gap motor rotor, and

two axial sides of the radial extensions of the axial gap motor rotor are configured to be covered by the magnet.

8. An axial gap motor comprising:

the axial gap motor rotor according to claim 2 ; and

the stator opposing the axial gap motor rotor in the axial direction.

9. The axial gap motor according to claim 8 , wherein

the stator is arranged at two axial sides of the axial gap motor rotor, and

two axial sides of the radial extensions of the axial gap motor rotor are configured to be covered by the magnet.

10. An axial gap motor comprising:

the axial gap motor rotor according to claim 3 ; and

the stator opposing the axial gap motor rotor in the axial direction.

11. The axial gap motor according to claim 10 , wherein

the stator is arranged at two axial sides of the axial gap motor rotor, and

two axial sides of the radial extensions of the axial gap motor rotor are configured to be covered by the magnet.

12. An axial gap motor comprising:

the axial gap motor rotor according to claim 4 ; and

the stator opposing the axial gap motor rotor in the axial direction.

13. The axial gap motor according to claim 12 , wherein

the stator is arranged at two axial sides of the axial gap motor rotor, and

two axial sides of the radial extensions of the axial gap motor rotor are configured to be covered by the magnet.

14. An axial gap motor comprising:

the axial gap motor rotor according to claim 5 ; and

the stator opposing the axial gap motor rotor in the axial direction.

15. The axial gap motor according to claim 14 , wherein

the stator is arranged at two axial sides of the axial gap motor rotor, and

two axial sides of the radial extensions of the axial gap motor rotor are configured to be covered by the magnet.

16. The axial gap motor rotor according to claim 1 , wherein:

the rotor core includes an outer circumferential portion located at a radially outer side of the radial extensions and extended in the circumferential direction from the radial extensions, and

the base, the radial extensions and the outer circumferential portion are integrally formed.

17. The axial gap motor rotor according to claim 1 , wherein:

the magnet is formed integrally with the rotor core.

18. The axial gap motor rotor according to claim 4 , wherein:

the magnetic path interruption portion comprises a gap that completely separates a first portion of the outer circumferential portion from a second portion of the circumferential portion, configured to interrupt a magnetic path arranged in at least either one of the radial extensions and the outer circumferential portion.

19. The axial gap motor rotor according to claim 4 , wherein:

the magnetic path interruption portion comprises a gap that completely separates an inner portion of at least one of the radial extensions from an outer portion of the at least one of the radial extensions.

20. The axial gap motor rotor according to claim 4 , wherein:

a number of magnetic interrupt portions matches a number of the radial extensions.