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:
Nov. 12, 2002
Filed:
Sep. 07, 2000
Applicant:
Inventors:
Yoshikazu Koike, Chino, JP;
Akihiko Ikegami, Okaya, JP;
Assignee:
Seiko Epson Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K 3/700 ;
U.S. Cl.
CPC ...
H02K 3/700 ;
Abstract
A PM type stepping motor is provided capable of further reducing the higher harmonic component of detent torque. n sets of teeth groups, each consisting of m stator polar teeth, are set for each of an outer yoke and an inner yoke, and the pitch P of the stator polar teeth, the pitch P of the teeth groups, and the pitch P of the N and S poles of permanent magnets are set such that the relationship: P ≠P , P ≠m·P , and P ≠m·P holds true, where P , P and P are electrical angles, and m and n are integers equal to or larger than 2.