Patent ID: 7948133
Filing Date: 2011-05-24
Classification: H02K

Abstract:
1. A rotor comprising: a rotating shaft having a depression formed in a peripheral surface of said rotating shaft and provided rotatably about a rotational axis line; a rotor core having a hole where said rotating shaft can be received, and a protrusion formed on an inner surface of said rotor core defining said hole, said protrusion being fittable in said depression; and a stress relaxation groove formed at a position adjacent to said protrusion, in the inner surface of said rotor core defining said hole, said stress relaxation groove being depressed away from a peripheral surface of said rotating shaft, the inner surface of said rotor core defining said hole being formed in a shape of an arc centered at said rotational axis line, a bottom surface of said stress relaxation groove located radially outward in said rotor core, included in an inner surface of said rotor core defining said stress relaxation groove, having an arc portion centered at said rotational axis line defining an inner surface of said hole, and said stress relaxation groove including a first inner side surface continuing from one end of said bottom surface such that said first inner side surface continues from said bottom surface and continues from a side surface of said protrusion, and a second inner side surface continuing from the other end of said bottom surface such that said second inner side surface continues from said bottom surface and continues from the inner surface of said hole.