The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 26, 2001
Filed:
Mar. 29, 2000
Yoshihito Nishikawa, Toyohashi, JP;
Mikitsugu Suzuki, Kosai, JP;
Takanori Ozawa, Anjo, JP;
Mitsuhiko Matsushita, Shizuoka-ken, JP;
Asmo Co., Ltd., Shizuoka-Ken, JP;
Abstract
A revolving magnetic field type motor has a rotor and a stator. The rotor has a plurality of permanent magnets. The permanent magnets defines a plurality of rotor magnetic poles. The number of the rotor magnetic poles is “P”. The rotor has a plurality of blocks aligned in the rotor's axial direction. The number of the blocks is “m”. Each block has a set of the rotor permanent magnets. One set of the permanent magnets is offset relative to an adjacent set of the permanent magnets by a predetermined offset angle in the rotor's rotational direction. The stator has a plurality of coils, the coils defining a plurality of stator magnetic poles around the axis of the stator, the number of the stator magnetic poles being “T”. The predetermined offset angle is selected from within a range from about zero degrees/((m−1)×n) to about 22.5 degrees/((m−1)×n). The number of the rotor magnetic poles “P” is 8n (n is an integer equal to or greater than one). The number of the stator magnetic poles “T” is 9n (n is an integer equal to or greater than one). This motor reliably decreases cogging torque.