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:
Jul. 06, 1976
Filed:
Mar. 05, 1974
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., , JA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02K / ;
U.S. Cl.
CPC ...
310156 ; 310 43 ; 310162 ; 264323 ; 260 4217 ; 428323 ;
Abstract
A synchronous motor is provided with a rotor including magnetic poles composed of a permanent magnet fixed around a rotor shaft, a stator facing the outer periphery of the rotor with an air gap formed therebetween, and a guard ring made of a non-magnetic material of low resistivity and fitly disposed around the outer periphery of the permanent magnet to restrain the surface loss caused by the magnetic flux linking with the guard ring, thereby preventing the reduction of the efficiency of the synchronous motor.