Crown Drop Effects on the Needle Roller Bearing Life in Oscillatory

Abstract

In this paper, the effects of chamfer dimension at the Lundbergs profile needle roller end and the grinding undercut of raceway on the pressure distribution, which are used in the oscillatory applications, are discussed. The frame of numerical method for the crown drop evaluation considered these two effects is presented, which makes it possible to profile the needle rollers axially until the longitudinal pressure distribution is neither any edge effects nor high-pressure concentration at the center part of contacts. And the crown drop designed by this method is larger than that by Lundbergs theory. The comparison results of accelerated rolling contact fatigue experiment show that the width of grinding undercut and radius of the chamfer must be considered in determining the crown drop of the needle rollers.