Patent ID: 9143014
Filing Date: 2015-09-22
Classification: H02K,Y10T

Abstract:
1. A rotor comprising: a rotatable shaft that is rotatable about a rotational axis of the rotatable shaft; a rotor core that includes a boss, which is fixed to the rotatable shaft, and a plurality of projections, which radially outwardly project from the boss and are spaced from each other in a circumferential direction, wherein each of the plurality of projections is formed as a soft magnetic pole and has a radially outer surface, which includes a circumferential center portion that is located radially outward of at least one of two circumferential end portions of the radially outer surface of the projection; a plurality of permanent magnets, each of which is formed as a magnet pole and is circumferentially placed between corresponding adjacent two of the plurality of projections, wherein each of the plurality of permanent magnets has a radially outer surface that is an arcuate surface, which extends arcuately in the circumferential direction; and a cover that is configured into a tubular form and is fitted to the radially outer surface of each of the plurality of projections and the radially outer surface of each of the plurality of permanent magnets, wherein: the circumferential center portion of the radially outer surface of each of the plurality of projections contacts a radially inner surface of the cover; and the at least one of the two circumferential end portions of the radially outer surface of each of the plurality of projections is radially inwardly spaced from the radially inner surface of the cover.