Simulation Study On Grinding Heat And Residual Stress Of Axle Box Bearing Ring Of High Speed Train

Axle box bearing is one of the basic components of the running gear of high-speed train.Its operation reliability directly affects the safe operation of the train.The raceway accuracy and mechanical properties of the bearing inner and outer rings are the key factors affecting the service performance of the bearing.Grinding is the key link of raceway machining of bearing rings.The grinding heat generated in the grinding process will cause residual stress on the surface of raceway,and even burn cracks.Therefore,it is of great practical significance to study the grinding heat of bearing ring raceway and its influence on raceway accuracy and surface residual stress.In this paper,the finite element simulation method is used to carry out the related research.The specific research work and results are as follows:(1)Taking high-speed train axle box bearing ring as the research object,ANSYS /mechanical software is used to simulate the grinding temperature field of bearing inner ring and outer ring raceway.The influence of different heat source models(rectangular heat source and triangular heat source)on the surface temperature field of bearing ring raceway was analyzed.The influence of grinding parameters(grinding wheel speed,workpiece speed,grinding depth)on the temperature field of bearing rings is studied.The influence of grinding parameters on grinding temperature is analyzed by orthogonal test.The results show that: there is no significant difference between the peak temperatures calculated by the two heat source models.With the increase of grinding wheel speed and grinding depth,the grinding temperature of raceway surface increases,while with the increase of workpiece speed,the grinding temperature decreases.The influence of grinding depth on grinding temperature is the largest,followed by workpiece speed,and the influence of grinding wheel speed on grinding temperature is small.(2)In ANSYS / mechanical software,the method of sequential coupling is used to simulate the thermal grinding force coupling of ring raceway grinding.The distribution of residual stress in surface and depth direction of raceway of bearing ring and the influence of grinding parameters on surface residual stress are studied.The results show that: the residual stress of raceway surface appears alternately in tension and compression.The residual tensile stress in X and Z depth direction increases first and then decreases.With the increase of grinding wheel linear speed and grinding depth,the residual tensile stress of raceway surface increases.With the increase of workpiece speed,the residual tensile stress of raceway surface decreases.(3)Based on the principle of least square method,the calculation program of straightness error,flatness error,roundness error and conicity error after ring raceway grinding is compiled by using MATLAB software.The influence of grinding heat on the machining accuracy of bearing rings is analyzed through the variation of raceway shape error under different grinding parameters.The results show that the straightness error,roundness error and conicity error increase with the increase of linear speed and grinding depth of grinding wheel,the straightness error,roundness error and conicity error decrease with the increase of workpiece speed,and the flatness error is very small without obvious regularity.In this paper,the temperature field,residual stress field and machining accuracy of bearing ring after grinding are obtained by finite element simulation.The reasonable selection of grinding parameters through the simulation results can effectively reduce the generation of grinding heat,reduce the residual stress and improve the machining accuracy of bearing rings,thus improving the machining quality and prolonging the service life of bearing rings.