Patent ID: 6236133
Filing Date: 2001-05-22
Classification: H02K

Abstract:
A three-phase brushless motor comprising:a rotor having a permanent magnet magnetized into P poles, the P poles being formed by alternately positioning N-poles and S-poles; anda stator having T teeth and three-phase coils consisting of U-phase coils, V-phase coils and W-phase coils, each coil being wound around the respective tooth, a rotating magnetic field being generated in the stator by supplying three-phase alternating current to the three-phase coils, wherein:P is 8n and T is 9n, where n is an integer equal to or larger than 1;tooth-groups, each group consisting of a center tooth, a first side tooth located at one side of the center tooth and a second side tooth located at the other side of the center tooth, are sequentially allocated to the U-phase coils, V-phase coils and W-phase coils;the coils of each phase consist of a center coil wound around the center tooth, a first side coil wound around the first side tooth and a second side coil wound around the second side tooth;the center teeth are positioned with an equal interval .theta.1 from one another, where .theta.1=(120.degree./n), measured in a central angle; andeach side tooth is positioned .theta.2 apart from the center tooth, where .theta.2 is measured in a central angle and (360.degree./T)<.theta.2.ltoreq.(360.degree./P).