Patent ID: 9071090
Filing Date: 2015-06-30
Classification: H02K

Abstract:
1. A motor comprising: a stator including a stator iron core wound with a stator winding; a rotor disposed for rotation with a shaft, the rotor including a rotary body whose outer most wall holds a permanent magnet, and the shaft extending through the center of the rotary body and being secured to the rotary body; a dielectric layer disposed in the rotary body around the shaft to decrease a rotary-body electrostatic capacity between the shaft and the outermost of wall of the rotary body; a bearing having an inner ring and an outer ring for rotatably supporting the shaft, wherein the bearing has a bearing electrostatic capacity measurable during rotation of the bearing between the inner ring and the outer ring thereof; and a conductive bracket for fixing the bearing, wherein the dielectric layer is made of a dielectric material so selected and sized that the rotary-body electrostatic capacity is equal to or smaller than one fifth (⅕) of the bearing electrostatic capacity.