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:
Sep. 14, 2004
Filed:
Oct. 25, 2001
Yuzuru Suzuki, Shizuoka-ken, JP;
Taketoshi Ohyashiki, Shizuoka-ken, JP;
Kunitake Matsushita, Shizuoka-ken, JP;
Minebea Co., Ltd., Nagano-Ken, JP;
Abstract
There is provided a stepping motor of low vibration realized by reducing cogging with a simple structure while maintaining the performances such as torque. A stepping motor of the invention is structured such that a stator unit is composed of a pair of stator sub-assemblies attached to each other in a back to back manner, each stator sub-assembly having a plurality of pole teeth formed at its inner circumference and housing a coil inside thereof, a rotor unit is rotatably disposed with a small gap from the plurality of pole teeth and having multiple magnetic poles formed on an circumference thereof, the multiple magnetic poles of the rotor unit being formed by magnetizing the rotor unit alternately with an S pole and an N pole in a circumferential direction, and that while a magnetic pole width consisting of a width of the S pole and a width of the N pole in a pair is set to a predetermined constant value, the width of the S pole and the width of the N pole in each pair are set to be different from each other.