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:
Dec. 19, 1989
Filed:
Apr. 06, 1988
Applicant:
Inventor:
Motoharu Shimizu, Kumagaya, JP;
Assignee:
Hitachi Metals, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ; H01F / ; C22C / ;
U.S. Cl.
CPC ...
310156 ; 148104 ; 310 44 ; 335302 ; 419 29 ; 420 83 ;
Abstract
A cylindrical permanent magnet of from 4-48 poles containing, as major components, R (R is at least one rare earth element selected from Nd, Pr, Dy, Ho and Tb and may further contain at least one rare earth element selected from La, Ce, Sm, Gd, Er, Eu, Tm, Yb and Y), B and Fe, and having multipolar anisotropy at the surface without suffering from cracking. The ratios of inner and outer magnet diameters are established as functions of the number of poles. Bushings of ferromagnetic materials allow for reduced permanent magnet thicknesses.