Nsk Corporation

Yasuo Utsumi

Yasuo Murakami

Shigeru Okita

Hiroshi Iwasa

Satoshi Kadokawa

Akihiro Kiuchi

Shoji Noguchi

Toichi Kondou

Yasuyuki Shimasaki

A rolling bearing contains no more than 0.3 wt % of nitrogen in a grinding allowance portion after carbonitriding and hardening heat treatments, contains from 0.9 wt % (inclusive) up to 1.6 wt % (inclusive) of carbon and from 0.05 wt % (inclusive) up to 0.3 wt % (inclusive) of nitrogen in the surface layer of the finished part and has a nitrogen gradient of no more than 0.5 wt %/mm in the surface layer of the finished part. The rolling bearings are improved in grinding efficiency and which have their rolling life extended significantly.

Rolling bearing and heat treatment method therefor

The rolling/sliding outer ring of the cam follower apparatus withstand peeling very well, even in sever lubrication conditions, through the steps that on the outer peripheral surface of the outer ring, the depth of the surface layer is taken to be 0 to 50 .mu.m, and the maximum residual compressive stress in this surface layer is between 50 and 110 kgf/mm.sup.2, the hardness of this surface layer is between Hv830 and Hv960, and the average wavelength of the very minute protrusions on the surface is less than 25 .mu.m, and the amount of residual austenite in the surface layer exceeds 7 volume %, after processing, while the inner peripheral surface, of the outer ring is superfinished.

Rolling-sliding mechanical member

An object of this invention is to provide a rolling bearing which is increased in rolling fatigue life when used with a lubricant contaminated by foreign matters, and which is improved in wear resistance and in seizure resistance. In a rolling bearing, at least one of the inner race, outer race and rolling elements thereof is made of an alloy steel which contains 0.10 to 1.0 wt of C, 0.50 to 3.0 wt % of Cr, 0.10 to 2.0 wt % of Mo, 0.15 to 1.0 wt % of Si, 0.20 to 1.5 wt % of Mn, and 0.2 to 1.0 wt % of Ni, and which is carbo-nitrided so that the sum (C+N) of the contents of carbon (C) and nitrogen (N) in the surface layer thereof is 1.0 to 2.0%, and the ratio (N/C) of the content of nitrogen (N) to the content of carbon (C) is 0.8 to 2.0.

Rolling bearing

Growing community of inventors

Kanagawa, Japan

Yasuo Utsumi