Rolling bearing and method of machining rolling element of the bearing

Abstract

In rolling bearings used in a circumstance undergoing high temperature, large loads and large vibrations, it has been known that early flaking phenomenon more tending to occur in the rolling element than in the bearing ring. In view of the above, according to the present invention, a rolling element with improved rolling contact fatigue resistance can be obtained while keeping hardness by devising a combination of mechanical surface hardening treatment and a heat treatment to a surface of a rolling element. A rolling bearing of long life can be provided even under large loads and large vibrations by incorporating the rolling element. That is, according to the present invention, a surface hardening treatment is applied after quenching and tempering to a rolling element to provide a surface with a residual compressive strength and, subsequently, secondary tempering and then finish grinding are applied to make the amount of residual austenite in the surface layer to 0 to 15%, the final residual compressive strength value to −600 to −1200 MPa and a working strain relieving degree to 10 to 60%. This can provide a long life rolling bearing under large loads and large vibrations.

Dependencies are inferred from the claim text.