Mechanical Performance Analysis Of High-Speed Railway Bearings And Modification Of Roller

Double row tapered roller bearings are widely used in high speed railway train.The life and reliability of the bearings has played a vital role in guaranteeing the railway’s safety which could not be ignored.Therefore,in order to extend the carrying capacity and service life of bearings,the mechanical properties of the bearings characteristic must be analyzed and the crown of the roller must be designed to reduce the maximum contact stress.This paper focuses on the study of the double row tapered roller bearings in high-speed train,the main work are as follows:The domestic and foreign development statuses of railway bearings have been analyzed.The present situations of bearings theories have been researched.According to the external load and displacement relationship of roller and raceway,a theoretical model has been established for load distribution of double row tapered roller bearings.It is concluded that different external loads,different numbers of roller and different clearances of bearings could have impact on the load distribution of bearings.Based on Hertz contact theory,the finite length contact theory is used to establish the mathematical model of roller and raceway.Cutting-slice method is used for calculating contact stress distribution of roller under the common way of crown.By comparing the contact stress of crowned roller,the optimum crown roller has been found.The crowned roller could weaken the stress concentration phenomenon caused by edge effect.So the crown method could extend the service life of high-speed railway bearings.After the skew condition of roller and raceway has been studied,a contact model under skew condition has been established.Using this model to redesign the crown of roller could eliminate the second stress concentration caused by skew.The results show that the redesign of roller’s crown could reduce the maximum contact stress of roller and prolong the service life of bearings.