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:
Mar. 22, 2005
Filed:
Aug. 31, 2004
Yuzuru Suzuki, Shizuoka-ken, JP;
Taketoshi Ohyashiki, Shizuoka-ken, JP;
Kunitake Matsushita, Shizuoka-ken, JP;
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 unitis composed of a pair of stator sub-assembliesattached to each other in a back to back manner, each stator sub-assembly having a plurality of pole teethformed at its inner circumference and housing a coil inside thereof, a rotor unitis rotatably disposed with a small gap from the plurality of pole teethand having multiple magnetic poles formed on ah circumference thereof, the multiple magnetic poles of the rotor unitbeing formed by magnetizing the rotor unitalternately 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.