Patent ID: 7535145
Filing Date: 2009-05-19
Classification: H02K

Abstract:
1. An axial air gap-type electric motor comprising: a stator having a plurality of magnetic pole portions provided at a side face thereof and arranged in a circumferential direction, and a rotor which is disposed in opposed relation to the magnetic pole portions, and is spaced a predetermined distance from the magnetic pole portions, the rotor including a plurality of rotor cores and permanent magnet groups arranged in the circumferential direction, each of the rotor cores made of magnetic material and each of the permanent magnet groups having at least one permanent magnet, wherein the permanent magnet groups are arranged in such a manner that each permanent magnet has its magnetic polarity oriented in the circumferential direction of the rotor, opposed magnetic poles of any two circumferentially-adjacent permanent magnet groups are of the same magnetic polarity, an axial distance between each permanent magnet and the respective magnetic pole portion along a rotation shaft direction is longer than an axial distance between the respective rotor core and the respective magnetic pole portion along the rotation shaft direction, the rotor includes a disk-like non-magnetic material, and the rotor core and the permanent magnet groups are mounted on the disk-like non-magnetic material so that magnetic fluxes of the permanent magnet are directed only toward the stator.