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. 26, 2008
Filed:
Aug. 08, 2003
Tsukasa Taniguchi, Hitachi, JP;
Hiroyuki Mikami, Hitachinaka, JP;
Satoshi Kikuchi, Hitachi, JP;
Fumio Jyoraku, Hitachiohta, JP;
Hideyuki Harada, Hitachi, JP;
Tsukasa Taniguchi, Hitachi, JP;
Hiroyuki Mikami, Hitachinaka, JP;
Satoshi Kikuchi, Hitachi, JP;
Fumio Jyoraku, Hitachiohta, JP;
Hideyuki Harada, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.