Mechanism of dent initiated flaking and bearing life enhancement technology under contaminated lubrication condition. Part II: Effect of rolling element surface roughness on flaking resulting from dents, and life enhancement technology of rolling bearings

The dent initiated flaking life of a bearing is sometimes shorter than the calculated life. Therefore, it is important to develop an enhanced-life bearing for contaminated lubrication conditions. In this paper, the authors indicated that the dent initiated flaking life of a raceway is significantly reduced in bearings where the general surface roughness of the rolling elements is increased by dent generation due to operating in contaminated lubrication. Additionally, we confirmed that bearings with rolling elements made of material with fine silicon and manganese nitride precipitates, for the purpose of reducing the degradation of surface roughness, are effective in enhancing bearing life.