Patent ID: 9716411
Date: 2017-07-25
CPC Classifications: H02K

Claim:
1. A permanent-magnet-type rotating electric mechanism comprising: a stator having stator windings wound on a plurality of tooth portions formed on a stator core; and a rotor having permanent magnets embedded between a plurality of magnetic poles formed along a circumferential direction of a rotor core, the rotor being rotatable integrally with a shaft, wherein the rotor core has a plurality of low permeability areas each having lower permeability than that of a material of the rotor core, the low permeability areas are located between an outer circumference of each magnetic pole and a side surface of each permanent magnet, the low permeability areas are formed asymmetrically with respect to a geometric center in the circumferential direction of each magnetic pole so that a magnetic center of the magnetic pole is displaced toward one side with respect to the geometric center, and the rotor core includes two rotor core parts that are placed upside down relative to each other so that a relative position in the circumferential direction of the low permeability areas of the two rotor core parts with respect to the permanent magnets differs, wherein Z is a natural number of slots of the stator, P is a natural number of magnetic poles of the rotor, m is a number of phases, and a number q of slots per pole per phase is represented as q=Z/(m×P), the magnetic center is displaced by an electric angle with respect to the geometric center of each magnetic pole, and if q satisfies (⅖)≦q<(½), the electric angle is set at 15 degrees or greater, and if q satisfies (½)≦q, the electric angle is set at 30 degrees or greater.