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. 13, 1999
Filed:
Sep. 11, 1997
Applicant:
Inventor:
Masatoshi Niina, Kuwana, JP;
Assignee:
NTN Corporation, Osaka, JP;
Primary Examiner:
Int. Cl.
CPC ...
F16C / ;
U.S. Cl.
CPC ...
384492 ; 384490 ; 384625 ;
Abstract
In a thrust ball bearing, the heat treating hardness and heat treatment hardening depth of a bearing ring 4a (4b) are prescribed such that, at any depth from the raceway surface 4a1 (4b1), the value which is seven times the dynamic shearing stress .tau..sub.ZY produced at a certain depth from the raceway surface 4a1 (4b1) by the rolling movement of the rolling element 4c does not exceed the hardness at that depth. More particularly, with Vickers hardness Hv=520 adopted as a reference hardness, heat treatment (for example, carburizing) is effected such that a hardened layer with Hv=520 is present at a depth not less than 4% of the diameter d of the balls 4c.