Rotor for motor
A rotor for a motor includes: a rotor core including accommodation holes penetrating the rotor core in an axial direction; permanent magnets respectively accommodated in the accommodation holes; an endplate configured to cover an end of the rotor core; and a soft magnetic core disposed on the endplate.
1. A rotor for a motor, the rotor comprising:
a rotor core including accommodation holes formed in a closed shape within the rotor core in an axial direction;
permanent magnets respectively accommodated in the accommodation holes;
an endplate configured to cover an end of the rotor core; and
a soft magnetic core comprising core pieces disposed on the endplate,
wherein the core pieces define a ring shape and are respectively positioned at the end of the rotor, adjacent the permanent magnets, and
wherein the core pieces redirect magnetic flux leaking in the axial direction from the permanent magnets to a circumferential direction in which torque may be generated by the motor.
2. The rotor of claim 1 , wherein the soft magnetic core is disposed between the rotor core and the endplate.
3. The rotor of claim 2 , wherein the soft magnetic core comprises a single core plate disposed between the rotor core and the endplate.
4. The rotor of claim 3 , wherein the core plate has a ring shape corresponding to the rotor core.
5. The rotor of claim 3 , wherein the core plate includes exposure holes through which the permanent magnets are exposed.
6. The rotor of claim 3 , wherein the core plate at least partially covers the accommodation holes.
7. The rotor of claim 2 , wherein the core pieces are disposed between the rotor core and the endplate.
8. The rotor of claim 7 , wherein the core pieces are disposed to be spaced apart from one another and cooperatively define a ring shape corresponding to the rotor core.
9. The rotor of claim 8 , wherein the permanent magnets are exposed through gaps formed between the plurality of core pieces.
10. The rotor of claim 7 , wherein the core pieces at least partially cover the accommodation holes.
11. The rotor of claim 1 , further comprising:
a coupling protrusion disposed on the soft magnetic core; and
a coupling groove disposed in the rotor core and configured to accommodate the coupling protrusion.
12. The rotor of claim 1 , further comprising:
a fixing protrusion disposed on the soft magnetic core; and
a fixing groove disposed in the endplate and configured to accommodate the fixing protrusion.
13. The rotor of claim 1 , wherein an accommodation groove is disposed in an inner surface of the endplate that faces the rotor core, and the soft magnetic core is accommodated in the accommodation groove.
14. The rotor of claim 1 , wherein a through-hole is disposed in the endplate, and the soft magnetic core is accommodated in the through-hole so as to be disposed on a same layer as the endplate.
15. The rotor of claim 1 , wherein the endplate is made of a non-magnetic material.
16. The rotor of claim 1 ,
wherein the core pieces are respectively accommodated in a plurality accommodation grooves disposed in an inner surface of the endplate that faces the rotor core, and
wherein shapes and sizes of the plurality of accommodation grooves respectively correspond to shapes and sizes of the plurality of core pieces.
17. The rotor of claim 1 , wherein the accommodation holes penetrate the rotor core and are covered by an outer side surface of the rotor core.
18. The rotor of claim 1 , wherein the outer portion of the rotor core forms a closed cylindrical surface.
19. The rotor of claim 1 , wherein the permanent magnets are surrounded by the accommodation holes.