Patent ID: 8330404

Claim:
A permanent-magnet-type rotating electrical machine comprising: a rotor having a plurality of first permanent magnets embedded in a cylindrical rotor core at equiangular intervals in a rotation direction, each of the first permanent magnets having a product of coercive force and magnetizing direction thickness smaller than that of a second permanent magnet and being oriented so that a magnetizing direction thereof is orthogonal to a diametral direction or in a diametral direction and a plurality of the second permanent magnets embedded in the rotor core at equiangular intervals in the rotation direction, each of the second permanent magnets having a product of coercive force and magnetizing direction thickness larger than that of the first permanent magnet, being oriented so that a magnetizing direction thereof agrees with a diametral direction, and being positioned between adjacent ones of the first permanent magnets so that the adjacent first permanent magnets and the second permanent magnet between them form a magnetic pole, the number of the magnetic poles being equal to the number of the second permanent magnets; a stator arranged to surround the rotor with a magnetic air gap interposing between them; and an armature coil formed on an inner circumferential part of the stator that faces the magnetic air gap, a narrow magnetic path being formed in the rotor core at an inter-pole yoke that magnetically connects adjacent ones of the magnetic poles to each other, so that the narrow magnetic path is magnetically saturated with flux of a magnetic field created by a predetermined magnetizing current passed to the armature coil, each of the plurality of first permanent magnets at each of the plurality of magnetic poles being magnetized with a magnetic field created by a magnetizing current passed to the armature coil, to irreversibly change the flux amount of the first permanent magnet.