Derivative analysis and evaluation of roll-slip fretting wear mechanism of ultra-thin-walled bearings under high service

Abstract

UTWB (Ultra-thin-walled bearings) are mainly used in high-precision robots and as power transmission components. In this study, the raceway wear mechanism of UTWB after high service (continuous 7000 h wear test) was analyzed. From the macroscopic observation, it is observed that the surface layer of the raceway has roll-slip wear. The wear mechanism was derivative analyzed and evaluated from the experimental conclusions. Another form of surface damage, associated with oscillatory movements tangential to the surface, was fretting wear. Compared with the residual stress of the non-high service raceway, the tangential and axial residual stresses of the outer and inner raceways with high service wear increased. Grain delamination appeared on the subsurface layer of the high serviced outer and inner ring raceway. The rolling wear and sliding wear of the inner ring raceway were more serious than those of the outer ring raceway. The formation of nanocrystalline layer increases the surface hardness of the raceway. Meanwhile, with the transfer from the surface layer of the raceway to the subsurface layer, the degree of grain refinement gradually decreases and the interplanar crystal spacing gradually increases. Through the above data analysis, the roll-slip wear mechanism of UTWB raceway was evaluated in multiple dimensions, and the reliability scheme to improve the actual working conditions of UTWB raceway processing-wear-service was put forward, which provides scheme and data support for relevant manufacturing enterprises and scholars.