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:
Nov. 13, 2001
Filed:
Apr. 03, 2000
Susumu Tanaka, Kanagawa, JP;
Manabu Ohori, Kanagawa, JP;
NSK Ltd., Tokyo, JP;
Abstract
The rolling bearing according to the invention comprises a dense nitride layer formed on the surface layer of the rolling elements and optionally an optimum carbonitride layer formed on the races. In this arrangement, the deterioration of durability due to vibration or impact load during transportation can be prevented, not to mention improvement of stillness. Further, the deterioration of impact resistance required for hybrid bearing can be prevented. The release of pilot pressure and defective of acoustic properties due to electrostatic attraction of dust can be prevented. At the same time, the rolling element of the invention comprises a compound layer having an extremely high hardness formed uniformly, making it possible to finish to a high precision. Moreover, a great effect can be exerted of preventing the change of properties with time at high temperature or the deterioration of acoustic properties under other severe working conditions. A novel rolling bearing is provided comprising an outer race, an inner race and a plurality of rolling elements or comprising an outer race, a shaft and a plurality of rolling elements, characterized in that the rolling elements have a dense nitride layer on the finished surface thereof and the nitride layer comprises a compound layer having a hardness Hv of 900 or more and a diffusion-hardened layer.