Inner Ring Raceway Research Articles

Roller bearing under high loaded oscillations: Life evolution and accommodation mechanisms

High loaded oscillating bearings are used on several industrial fields such as robotics, wind power, aeronautics and aerospace. These bearings are subjected to extremely high local contact pressures and relatively low oscillatory speed. In this work, endurance tests on commercial single row spherical roller bearings enable to propose a degradation scenario for the bearing lifecycle. Topographical analyses carried out at each phase of the bearing life allowed to understand the degradation evolution at the interface between the inner-ring raceway and rolling elements. The analysis of the experimental results, with the support of numerical stress analysis, led to the understanding of the involved accommodation mechanisms. Then, a comparison with the wear processes in deep-groove ball bearings is provided.

Wear in a high-speed roller bearing

AbstractWear phenomena in a worn high-speed roller bearing made of ALSI 52100 steel were studied using metallography, electron-probe microanalysis, and microhardness measurements. Friction layers related to thermal effects were observed in the surface material of the bearing components, as already reported for sliding surfaces. A hard, martensitic, light-etching layer was observed on the surfaces of the rollers and the outer-ring raceway, while a soft dark-etching layer was observed on the surface of the inner-ring raceway. Failure of the bearing was due to excessive wear of the inner-ring raceway. Thus it was concluded that the most important harmful effect of the observed microstructural changes was to upset the hardness balance between roller surfaces and inner-ring raceway, leading to machining of the inner-ring raceway by the rollers. Surface pitting and other phenomena relating to rolling-contact fatigue were not significant wear mechanisms.