Effect Of Interference,Temperature Difference And Modification On The Loading Capacity Of Axle Box Bearings For Urban Rail Vehicles

Load distribution,stress and deformation is a concrete reflection of bearing loading capacity after carrying load.Bearing capacity directly affects the fatigue life and reliability of bearing,which directly related to the safety of urban rail vehicles.Therefore,it is of great significance to study the capacity of axle box bearings for urban rail vehicles.In the present paper,cylindrical roller bearings of urban rail vehicles axle boxes are studied with the principle of bearing design and finite element methods.Published papers about the influence of interference fit between axle and inner ring and temperature difference on the load distribution for cylindrical roller bearings are not found in domestic journals.When establishing the finite element model in the present paper,the effect of friction and overall deformation of the inner and outer rings on the load distribution are considered.Respectively,the effect of interference fit between the axle and the inner ring,radial clearance,and temperature difference on the cylindrical roller bearings load distribution,contact areas between rollers and inner and outer rings,contact stress and equivalent stress are studied.Then,finite element analysis simulating more real assembly and work conditions of cylindrical roller bearing is done considering the above factors,thereby load distribution of the bearing studied in actual conditions is confirmed.According to bearing load distribution,the single roller that stress is maximal contacting with inner and outer rings considering the influence of interference fit,radial clearance and temperature difference is studied.The distribution law of contact stress and equivalent stress between roller,inner and outer rings are deep researched.Then,the effect of modification on contact stress and equivalent stress distribution is discussed.At last,the optimal modification amount is determined,which provides theoretical basis for the design,manufacture and application of cylindrical roller bearing.The research results of the present papers indicate that the interference fit between axle and bearing inner ring and the temperature difference among inner ring,outer ring and roller have a considerable influence on capacity of cylindrical roller bearings,therefore,the effect of interference fit and temperature difference among bearing main components should be considered when calculating bearing fatigue life and doing roller crowing,stress concentration caused by edge effect can be avoided by logarithmic crowing on rollers,the maximum stress of the bearing can be reduced,thereby the fatigue life of bearing can be dramatically improved.