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. 13, 2003
Filed:
Jun. 22, 2001
Applicant:
Inventors:
Kiyoshi Hirakawa, Kanagawa, JP;
Hiroshi Fukushima, Kanagawa, JP;
Assignee:
NSK Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21D 9/36 ; C21D 1/10 ; C23C 8/26 ; F16C 3/334 ;
U.S. Cl.
CPC ...
C21D 9/36 ; C21D 1/10 ; C23C 8/26 ; F16C 3/334 ;
Abstract
In a rolling shaft relatively rolling with respect to rolling members provided in a radial needle roller bearing, the rolling shaft is composed of a steel containing 0.5 to 1.2 wt % carbon and is provided with a surface layer containing 0.05 to 0.4 wt % nitrogen, having Vickers hardness being Hv650 or more through a high frequency quenching performed thereto and a residual austenite being 15 to 40 vol %, and a core portion of the rolling shaft contains 0 vol % of the residual austenite.