Patent ID: 8933605
Filing Date: 2015-01-13
Classification: F04F,H02K,Y10T

Abstract:
1. A brushless motor comprising: a stator comprising a stator core with teeth protruding inwardly and windings wound on the teeth, and a rotor comprising a shaft, a rotor core fixed to the shaft, and a ring magnet fixed to the circumferential outer surface of the rotor core, the magnet comprising a plurality of magnetic poles radially magnetized so that north poles and south poles are arranged alternately in the circumferential direction, wherein boundary lines between magnetic poles are skewed by an angle α relative to an axis (Z) of the shaft, and a plurality of grooves formed in the circumferential outer surface of the rotor core, each groove extending axially from one end of the rotor core to the other end of the rotor core; wherein the boundary lines between adjacent magnetic poles do not radially overlap the grooves.