Patent ID: 9018816
Filing Date: 2015-04-28
Classification: H02K

Abstract:
1. A rotor comprising: first and second rotor cores, each having a core base of a substantially disk shape, wherein the core bases are placed to oppose each other, the first and second rotor cores each having a plurality of claw-like magnetic poles arranged in an outer periphery of the core base in a circumferential direction at even intervals and formed to protrude outwards in a radial direction and to extend in an axial direction, the claw-like magnetic poles of the first rotor core and the claw-like magnetic poles of the second rotor core being arranged alternately in the circumferential direction; a field magnet arranged between the core bases in an axial direction of the rotor and magnetized in the axial direction to cause the claw-like magnetic poles of the first rotor core to function as a first magnetic pole and cause the claw-like magnetic poles of the second rotor core to function as a second magnetic pole; interpole magnets each arranged between a circumferentially adjacent pair of the claw-like magnetic poles, each interpole magnet being magnetized in the circumferential direction to have the same polarity as the claw-like magnetic poles opposed thereto in the circumferential direction; and a holding member for holding the interpole magnets in order to restrict radially outward movement of the interpole magnets, wherein the holding member includes a pair of fitting members fitted to the axial ends of the first and second rotor cores, which are assembled to each other, back side auxiliary magnets, which are magnetized in the radial direction, are arranged at positions radially inward of the claw-like magnetic poles, and each of the fitting members has a back side axial engagement portion to be engaged in the axial direction in order to restrict axial movement of the back side auxiliary magnets.