US 12,294,243 B2
Rotating electric machine
Hidenori Sasaki, Tokyo (JP); Kenta Motoyoshi, Tokyo (JP); Shohei Fujikura, Tokyo (JP); Hiroko Ikeda, Tokyo (JP); and Koji Kawamura, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 17/927,741
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Aug. 20, 2020, PCT No. PCT/JP2020/031489
§ 371(c)(1), (2) Date Nov. 25, 2022,
PCT Pub. No. WO2022/038750, PCT Pub. Date Feb. 24, 2022.
Prior Publication US 2023/0208225 A1, Jun. 29, 2023
Int. Cl. H02K 1/278 (2022.01); H02K 1/276 (2022.01); H02K 1/28 (2006.01); H02K 7/00 (2006.01)
CPC H02K 1/278 (2013.01) [H02K 1/2773 (2013.01); H02K 1/28 (2013.01); H02K 7/003 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A rotating electric machine, comprising:
a stator; and
a rotor provided on an inner peripheral side of the stator so as to be rotatable with respect to the stator,
wherein the rotor includes:
a rotor core;
a plurality of permanent magnets provided to the rotor core; and
a shaft which is fixed to a center portion of the rotor core, and extends in an axial direction of the rotor, wherein the rotor core has a plurality of holes arranged in a circumferential direction of the rotor,
wherein the plurality of holes include a plurality of first holes and a plurality of second holes,
wherein the plurality of permanent magnets are inserted only into the plurality of first holes of the plurality of holes, respectively,
wherein the plurality of first holes and the plurality of second holes are alternately arranged one by one in the circumferential direction,
wherein the rotor core includes a plurality of core portions arranged in the circumferential direction with the plurality of second holes defined therebetween, respectively,
wherein the plurality of permanent magnets are magnetized such that magnetic-pole surfaces facing each other in the circumferential direction have different poles,
wherein each of the plurality of core portions includes:
a first core portion located on one magnetic-pole surface side of each of the plurality of permanent magnets; and
a second core portion located on the other magnetic-pole surface side of each of the plurality of permanent magnets,
wherein the rotor core includes a first rotor core in at least a part in the axial direction,
wherein the first rotor core includes a first annular portion and a plurality of first coupling portions,
wherein the first annular portion is provided on an inner peripheral side with respect to the plurality of core portions, and is formed such that the shaft is inserted thereinto,
wherein each of the plurality of first coupling portions couples the first annular portion and the first core portion of each of the plurality of core portions to each other,
wherein each of the plurality of first coupling portions includes at least one coupling path,
wherein a sum of a width of a portion having the smallest width in the at least one coupling path is smaller than a length of a joining boundary having an arc shape between the first annular portion and each of the plurality of first coupling portions,
wherein the at least one coupling path is a plurality of coupling paths,
wherein a non-magnetic hole is formed between two coupling paths adjacent to each other among the plurality of coupling paths, and
wherein, in a cross section perpendicular to the axial direction, the non-magnetic hole has a circular fastening hole that allows a fastening member to pass therethrough in the axial direction.