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:
Sep. 27, 2005
Filed:
Mar. 20, 2000
Applicants:
Osamu Kodama, Komatau, JP;
Kaoru Hasegawa, Komatsu, JP;
Nobuaki Kawasaki, Komatsu, KR;
Inventors:
Assignee:
Komatsu Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D053/10 ;
U.S. Cl.
CPC ...
Abstract
A cylindrical roller bearing or needle roller bearing for use with a rolling raceway surface is subjected to a carbonitriding treatment to produce a layer containing 30 to 80% retained austenite in the vicinity of its surface that contacts a carburized layer of a rolling raceway surface of a roller bearing. The amount of retained austenite of the surface layer of the roller bearing is increased by about 30%. The surface layer is then heat treated to apply a residual compression stress. The surface then receives surface finishing to produce micro concavo-convex portions in a random direction.