Patent ID: 8624457
Filing Date: 2014-01-07
Classification: H02K

Abstract:
1. A permanent magnet electric motor in which a rotor is configured by a rotor core and a plurality of magnetic poles formed inside the rotor core by using two or more types of permanent magnets selected such that the product of the coercivity and the thickness in the magnetization direction of each magnet is different from each other, in which a stator is located outside the rotor with an air gap intervening between them and configured by an armature core and an armature coil, comprising: when in the two or more types of permanent magnets, one type of permanent magnet has a smaller value as the product of the coercivity and the thickness in the magnetization direction compared with any other type of permanent magnet within the rotor core is called “permanent magnet of small product type”, and another type of permanent magnet has a larger value as the product of the coercivity and the thickness in the magnetization direction compared with any other type of permanent magnet within the rotor core is called “permanent magnet of large product type”, the plurality of magnetic poles configured by a series of magnets, which is formed by two or more permanent magnets including the two or more types of permanent magnets located in series in a magnetic circuit, and a permanent magnet of the large product type located in parallel to the series of magnets in a magnetic circuit, wherein a permanent magnet of the small product type in permanent magnets forming the series of magnets is magnetized by a magnetic field generated by a current of the armature coil so that the magnetic flux of the permanent magnet configuring the magnetic pole is changed quantitatively and irreversibly.