Rolling bearing

Abstract

Disclosed is a rolling bearing wherein the bearing life is increased by suppressing brittle peeling and brinelling-caused peeling of the raceways of the inner and outer rings and the rolling elements of the bearing. Steel (anti-brittle peeling steel) containing 1.80-1.89% of chromium in weight ratio undergoes a carbonitriding treatment and a quenching and tempering treatment. This chromium reduces generation of a white layer which is an aggregate of carbon, and suppresses the brittle peeling of raceways (1a, 4a) and the like, the brittle peeling being caused by the white layer. A residual austenite region (5) obtained by the quenching and tempering treatment provides toughness to a surface of the steel, and suppresses the brinelling-caused peeling caused by a foreign substance such as abrasion powder. Suppression of both the brittle peeling and the brinelling-caused peeling can not only increase the bearing life, but also reduce a cost required for maintenance such as replacement of lubricant oil.

Description

Technical field [0001] The present invention relates to a rolling bearing, which suppresses brittle peeling of the raceway surfaces of the inner and outer rings, the surface of the rolling elements, and peeling of the starting point of indentation caused by foreign matter in lubricating oil, and is used in automobile parts such as transmissions. Background technique [0002] As the embodiment of the invention of this application figure 1 As shown, the rolling bearing is formed such that the inner ring 1 covers the cage 2 and the rolling elements 3 including steel balls are accommodated in the cage 2, and then the outer ring 4 is mounted. The inner ring 1 and the outer ring 4 smoothly around the axis The ground rotates relatively. The inner ring 1, outer ring 4, and rolling elements 3 are lubricated by lubricating oil. Although this lubricating oil is in a clean state at the beginning of use, wear powder generated from peripheral structures of the bearing such as gears is mixed w...

AI Technical Summary

Problems solved by technology

However, there is no overlap between the concentration range of chromium (2.0% to 5.0%) in which the effect of inhibiting brittle peeling is exerted and the range of concentration of chromium (0.2% to 1.2%) in which the effect of suppressing peeling caused by indentation is not overlapped, and it is considered that they cannot be simultaneously exerted the effect of both

Therefore, there is a problem that either brittle peeling or peeling caused by indentation cannot be sufficiently suppressed, and a sufficient improvement in the fatigue life of the bearing cannot be achieved.

Images