Analysis of damage evolution and causative factors of outer raceway micromorphology of small needle roller bearings under impact load

Abstract

Purpose This paper aims to investigate the damage evolution of bearing raceways under impact conditions from the perspective of three-dimensional (3D) surface morphology changes and to analyze the causal factors with the aid of simulation. Design/methodology/approach An experimental device containing an impact generating mechanism, a transmission mechanism and a torque load is designed for the experiments of impact damage to the outer raceway of a small needle roller bearing HK1208 without an inner ring. Microscopic images and height color maps of each experimental stage were obtained using a 3D laser measurement microscope. The characterization parameters of the surface 3D morphology were extracted and analyzed. Dynamics simulations of the impact condition were performed using the finite element method to investigate the variations and distribution characteristics of the roller forces on the raceway. Findings The changes in roughness and 3D micromorphology show that the surface flattening phenomenon caused by the flattening effect occurs before the surface of the bearing raceway is damaged. The result of dynamic simulations shows that the maximum load of the bearing under the impact state is obviously greater than that under a steady state, and the load distribution under the two conditions is significantly different. Originality/value This paper provides new ideas for analyzing the damage of bearings under impact conditions by analyzing the real 3D morphology of bearing raceways in combination with the finite element method.