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.

Date of Patent:
Jan. 26, 1999

Filed:

Jul. 02, 1997
Applicant:
Inventors:

Tadao Kodaira, Maebashi, JP;

Tsugio Onodera, Gunma, JP;

Susumu Aoki, Kiryu, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02K / ; H02K / ; B62D / ;
U.S. Cl.
CPC ...
310 89 ; 310 43 ; 310 91 ; 180140 ; 180148 ;
Abstract

In a yoke arrangement for electric motors which are particularly suitable for use in electric power steering devices, the yoke comprises a first tubular portion, a second tubular portion which has a smaller diameter than the first tubular portion, and a tapered section connecting the two tubular portions. The length of the tapered sections is desired to be minimized so that the overall length of the electric motor may be minimized. Reducing the length of the tapered section and thereby increasing the taper angle of the tapered section leads to the reduction in the mechanical strength of the yoke against an axial force. To compensate for this reduction in mechanical strength, the wall thickness of the tapered section is made larger than that of the first portion. Thus, the overall mechanical strength of the yoke can be ensured with a minimum increase in the material cost and manufacturing cost. The yoke may be formed by plastic deformation such as swaging and expansion.


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