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:
Jun. 29, 1993
Filed:
Mar. 29, 1991
Applicant:
Inventors:
Assignee:
Seiko Epson Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ; H02K / ; H02K / ;
U.S. Cl.
CPC ...
310156 ; 310 42 ; 310181 ; 310262 ; 29598 ;
Abstract
A DC brushless motor which includes a hollow cylindrical stator (2) having a plurality of exciting coils (6) secured to an inside thereof; a solid cylindrical rotor (7) provided within the stator and having at least two permanent magnets (30) therein so as to form a magnetic circuit with the stator; a rotary shaft (8) secured concentrically with said rotor; and a pair of bearings (10, 12) secured to opposite ends of the stator for supporting the rotary shaft for rotation. The permanent magnet is placed between a pair of high permeability yoke portions or pole pieces each extending in a radial direction to form a magnetic circuit and made of a rare earth element-transition metal-boron alloy.