Study On Residual Stress Of The Rolling Bearing Raceway Finishing

As one of the most important infrastructure components, rolling bearing plays a decisive role in the performance and the acceptable life of products. There are gaps between the high performance rolling bearings produced in China and the same type of bearings produced developed countries. The highlight point is the fatigue life. The residual stress distribution of bearing raceway has an important impact on crack initiation and propagation. It is an important factor of bearing fatigue life. Finishing is the final process during rolling bearing raceway processing in bearing manufacturing industry. The influence of finishing on the residual stress distribution of the rolling bearing raceway is considerable. In this paper, the residual stress distribution of the rolling bearing raceway after finishing was researched with theoretical analysis, finite element analysis and experiments, and the main work is as follows.According to the general procedure and processing characteristics of finishing, combined with the mechanism of residual stress generated during the machining process, the cause of residual stress during finishing was analyzed from a macro point of view. The uneven plastic deformation caused by mechanical action is the main reason of residual stress comes into being during finishing. Then the cause of residual stress during finishing was analyzed from a microscopic view. The plastic deformation does not exist under swipe effect, and no residual stress comes into being. Burnishing effect occurs under plowing effect, residual compressive stress comes into being in rolling bearing raceway surface. Plastic protruding effect and burnishing effect exist micro cutting process, the residual stress in rolling bearing raceway surface will be residual compressive stress.According to the grains distribution of whetstone and forces between grains and workpiece material, the connection of the force on whetstone and pressure on bearing raceway surface was established. The relationship between tangential force direction and whetstone oscillation frequency, workpiece rotation speed and processing time was analyzed. Finite element model of rolling bearing raceway finshing was established. Results of finite element analysis show that the residual stress of rolling bearing raceway surface is residual compressive stress. The maximum value of residual compressive stress lies in subsurface. The circumferential residual stress is greater than the axial residual stress. The residual compressive stress will increase with the force on whetstone, but if the force is larger the increment will be smaller. Cutting angle range has slightly effort on residual stress of the bearing raceway.After rolling bearing raceway finishing experiment, residual stress of the bearing raceway surface was measured. The dates were compared with finite element analysis results. There is little difference. The difference is acceptable, considering the error of instrument, the discrete distribution of residual stress and the simplification of finite element model. Results show that finite element model is appropriate.The influence of grinding residual stress to finishing residual stress was researched with finite element method. Results show that the influence of little initial stress can be ignored. Initial compressive stress is beneficial to increase the residual compressive stress of rolling bearing raceway finishing.