Patent ID: 8179010

Claim:
A rotor, comprising: a rotor iron core comprising a plurality of slots formed around an outer circumferential portion thereof; a plurality of magnet pieces which are inserted into the plurality of slots, respectively, such that a magnetic orientation of the magnet pieces is changed every predetermined number of the slots; and two end plates, one end plate disposed on each end side in an axial direction of the rotor iron core, the two end plates covering the plurality of slots in the axial direction, wherein the rotor iron core further comprises a plurality of cutout portions, which are located at an interval between adjacent ones of the slots, each of the cutout portions extending in the axial direction of the rotor iron core, one of the two end plates comprises a plurality of injection openings, each of which corresponds to a respective one of the plurality of slots, and a plurality of communicating grooves each of which is formed so as to communicate with one of the cutout portions and with one of the plurality of slots.