Research On Frictional Properties And Temperature Distribution Of High-Speed Railway Axle Box Bearing

As a key part of train travel department,the frictional properties and temperature distribution of high-speed railway axle box bearing is affecting the running condition and safety of the train.The most common faults of the train,such as hot shaft and ignition axis,are closely related to friction and heat.In the past,the research on the frictional properties and temperature distribution of axle box bearing has been mainly based on theoretical research and experiment research.The traditional theoretical research is not completely applicable,and the structure and operating conditions of bearing are not considered.Experiment research need a high cost,and cannot analyzed the mechanism of temperature rise and the influence rule of each parameter index.According to above problem,this parper studied the frictional properties and temperature distribution of high-speed railway axle box bearing,established bearing's frictional analysis theory model and thermal network analysis model.Then made a high-speed train bearing's heat test to verify the accuracy of theoretical model.Finally,based on the two models and the actual engineering examples,analyzed the influence factors of the frictional properties and temperature distribution.The main research of the paeper is as follows:(1)Establish bearing's frictional properties analysis theory model based on quasi-statics theory and elastohydrodynamic lubrication theory.Including bearing's load distribution model,contact mechanics model of roller-raceway and roller-flange,lubrication state judgment model of roller-raceway and roller-flange,frictional load distribution model of roller-raceway and roller-flange and frictional torque calculation model.(2)Establish bearing's thermal network analysis model based on heat transfer theory.Including the calculation of heat source and heat impedance of bearing system,the partition of network node,and the establishment and solution of thermal network model.(3)Temperature rise experiment research of high-speed railway axle box bearing.(4)Analysis the influence factors of frtctional torque.(5)Analysis the influence factors of temperature distribution.The main conclusions of the parper are as follows:(1)Established a frictional properties analysis theory model and thermal network analysis model of high-speed railway axle box bearing.Provided a numerical solution to calculate load distribution,contact stress distribution,frictional load and frictional torque distribution,and temperature distribution.The experiment results show that the difference between experiment value and theoretical value is less than 20%,which verified the accuracy of the analytical model.(2)Provided a theoretical basis for axle box bearing's structural design and type selection from the viewpoint of tribology.Including that the increase of load causes the frictional torque improve,and the effect of radial load is more pronounced.In train's speed interval,the frictional torque first decrease and then increase.When outter contact angle increase,bearing's frictional torque decrease significantly,while the inner contact angle and flange tilt angle have little effect on the frictional torque.Reasonable lubrication parameter selection can greatly reduce frictional torque.(3)Provided a theoretical basis for axle box bearing's temperature monitoring and failure prediction.Including that bearing is generally at a low temperature distribution trend,and the highest temperature is appear in the contact area of roller and inner raceway.The increase of radial load will rise the temperature difference of each bearing part,while the increase of axial load will make the temperature distribution enevly.The increase of train's speed will increase the temperature value but cannot change the temperature distribution trend.