Permanent magnet electric motor

摘要

According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.

主权项

1. A permanent magnet electric motor comprising:
a rotor including: a rotor core divided into two or more parts in an axial direction thereof so as to form two or more divided core parts; and a plurality of magnetic poles disposed inside the respective core parts and formed by two or more types of permanent magnets selected such that a product of coercivity and thickness in a magnetization direction of each magnet is different from each other, each position of the magnetic poles in the core parts being skewed in a circumferential direction; a stator located outside the rotor with an air gap therebetween and including an armature core and an armature winding, the armature winding generating a magnetic field which magnetizes at least one permanent magnet forming the magnetic poles of the rotor; and conductive short circuited coils disposed at an angle displaced according to a skewed angle of the respective core parts in the circumferential direction of the rotor and connected to each other with a stepped part at a boundary part of the respective core parts, the short circuited coils generating a short-circuit current based on a magnetic flux that is generated during magnetization upon magnetizing the permanent magnets, the short circuited coils respectively comprising: a conductive panel disposed at the boundary part of each core part; a conductive bar protruding toward each core part in an axial direction of the rotor from each position of front and rear faces of the conductive panel displaced to each other corresponding to the skewed angle of the core parts in the circumferential direction of the rotor; and a short circuit connection part connecting tips of the conductive bars with each other at an axial end portion of the core part.