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:
Aug. 03, 1993
Filed:
Dec. 02, 1991
Akira Nishio, Fujieda, JP;
Masaru Kumazawa, Fujieda, JP;
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
A first multi-phase dc motor comprising: a field-magnet portion having P field magnetic poles positioned as a circular array at angularly equally spaced intervals; and an armature having cores as angularly equally spaced N protruding poles providing N slots therebetween with .phi.-phase coils disposed therein, either said field magnet portion or said armature being rotatable with respect to the other; and P, N, and .phi. being defined by P=2n, N=2n.+-.1, and N is not m times .phi. wherein n and m are natural numbers. A second multi-phase dc motor comprising: a field-magnet portion having P field magnetic poles positioned as a circular array at angularly equally spaced intervals; and an armature having cores as angularly equally spaced N protruding poles providing N slots therebetween with .phi.-phase coils disposed therein, either said field magnet portion or said armature being rotatable with respect to the other; and P, N, and .phi. being defined by P=2n, N=2(n.+-.1), and N is not m times .phi.. According to the invention, frequency of cogging per one turn is more than that of the conventional motor with the same number of magnet poles, so that degree of cogging torque is reduced.