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:
Apr. 03, 1990
Filed:
Mar. 23, 1989
Hiroaki Aso, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A permanent magnet DC machine comprising a rotor and a stator diametrically opposed to the rotor through a fine air gap therebetween. The stator comprises a yoke, main magnetic poles of anisotropic permanent magnet provided on an inner circumferential surface of the yoke and auxiliary magnetic poles provided respectively adjacent to the main magnetic poles side by side, each of the auxiliary magnetic pole being made of a material having higher reversible permeability than said permanent magnet. Each pair of the main and auxiliary magnetic poles are arranged so that they are in contact with each other at a radially inner portion of the magnetic poles and are separated from each other at a radially outer side of the magnetic poles to thereby form a magnetic leakage-path breaking air gap portion therebetween. A circumferential length of the air gap portion at the radially outer side is larger than a radial distance of said fine air gap and a nonmagnetic member is provided in the air gap portion to prevent the leakage of magnetic flux.