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:
May. 10, 1983
Filed:
Sep. 28, 1981
Hitachi, Ltd., Tokyo, JP;
Abstract
A field pole structure of a DC motor has a plurality of field magnetic poles attached to the inner surface of a yoke of the DC motor to oppose an armature. Each magnetic pole includes a permanent magnet, and an auxiliary pole member coupled to an end of the permanent magnet directed in opposition to the rotational direction of the armature and having permeability higher than reversible permeability of the permanent magnet. The permanent magnet has a single magnet body constructed by integrally formed first and second magnet members, the first magnet member being disposed at a half of the permanent magnet remote from the auxiliary pole member and made of a magnetic material of large coersive force, and the second magnet member being interpoled between the first magnet member and the auxiliary pole member and made of a magnetic material of large residual magnetic flux density, the boundary portion between the first and second magnet members being a region in which the magnetic material of large coersive force and the magnetic material of large residual magnetic flux density are mixed.