Patent ID: 7291945

Claim:
An AC (alternating current) motor comprising: a rotor comprising a rotation shaft rotatable around a longitudinal central axis in an axial direction of the rotation shaft, N (north) magnetic poles and S (south) magnetic poles fixedly disposed by turns around the rotation shaft in a circumferential direction of the rotation shaft, and rotor-side neutral poles disposed fixedly and juxtaposedly to the N magnetic poles and the S magnetic poles, respectively, along the axial direction, a back yoke magnetically linked with the N magnetic poles and the S magnetic poles so as to serve as a back yoke member together with the N magnetic poles and the S magnetic poles; and a stator comprising a plurality of modules disposed in the axial direction to be opposed to the rotor, each module comprising: a winding wound along the direction of the rotation shaft in a loop shape, stator-side neutral poles disposed to be opposed to the rotor-side neutral poles; stator poles disposed to be opposed to either of the N magnetic poles and the S magnetic poles; and back yokes magnetically linking the stator-side neutral poles and the stator poles to each other.