Patent ID: 7911091

Claim:
A cooling structure of a rotating electrical machine including a stator and a rotor, the cooling structure comprising: magnet accommodating holes provided in a rotor core of the rotor, the magnet accommodating holes extend between axial core end faces of the rotor core, wherein permanent magnets are accommodated in the magnet accommodating holes; a plurality of voids, which prevent leakage flux, in contact with the permanent magnets and extending between the axial core end faces; and a rotor cooling-liquid supply passage that supplies cooling liquid to one core end face, wherein: the cooling liquid supplied from the rotor cooling-liquid supply passage is introduced into the voids to prevent leakage flux, the permanent magnets are cooled by the cooling liquid flowing through the voids, a pair of voids are provided for each permanent magnet, each void having one end face corresponding to a surface of a corresponding permanent magnet that faces a commutating pole portion interposed between the permanent magnets, and in a cross section orthogonal to a rotating shaft, each void is formed between a line connecting a central axis of the rotor core with a corresponding one of closest portions located closest to each other in a circumferential direction of the rotating shaft of a pair of the permanent magnets located adjacent to each other in the circumferential direction of the rotating shaft and a side of a permanent magnet having the closest portion which extends from the closest portion in a direction connecting magnetic poles of the permanent magnet.