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:
Jan. 13, 1998
Filed:
Jul. 23, 1996
Masafumi Sakamoto, Gunma, JP;
Youji Unoki, Gunma, JP;
Japan Servo Co., Ltd., Tokyo, JP;
Abstract
A permanent magnet type stepping motor wherein and that at least one pitch formed by two adjacent small pole teeth of each of stator magnetic poles is different from other pitch formed by other two adjacent small pole teeth of each of the stator magnetic poles, wherein the tooth width of at least one of the two adjacent small pole teeth forming the different pitch is made different from that of the remaining small pole teeth, each stator magnetic poles having at least four small pole teeth and wherein a rotor has a rotor magnetic pole having a plurality of small pole teeth arranged at equal pitches, facing said stator magnetic poles through a gap. A permanent magnet type stepping motor has a stator having n pieces of stator magnetic pole each having m pieces of pole tooth, and a rotor having a plurality of pole teeth arranged at equal pitches n is an integer not less than three, m is an even number not less than four, a pitch of the rotor pole teeth is 2.pi., a pitch formed between (m/2)th stator pole tooth and �(m/2)+1!th stator pole tooth is set to (.tau..+-..theta..sub.0), and the other pitch is set to .tau., where .vertline.2.pi.-.tau..vertline.<.pi./12, .pi./5.ltoreq..theta..sub.0 <.pi./2, and .tau. and .theta..sub.0 are each electrical angle.