Analysis On Conyexity And Dynamic Performance Of Tapered Roller Bearing For High Speed Railway Coach

As the key component of high speed railway coach axle boxes, the convexitydesign and dynamic characteristics of tapered roller bearings directly affect theperformance and reliability of the axle boxes system, which influences regular runningand safety of high speed railway coach. Therefore, it is very significant to study onmechanical performance and temperature rise of axle boxes bearing.Taking double-row tapered roller bearing of high speed railway coach as researchobject, finite element contact models of rollers with different convexity and racewayshave been established in the ANSYS/ANSYS WORKBENCH environment. The statusof stress distribution nearby contact points between roller and raceways under contactloadings was analyzed. Considering the effects of different convexity, convexity valuesand load on contact stress and stress distribution, the optimal convexity and convexityvalue under a certain load were obtained. The roller with logarithm profile andreasonably convexity values can reduce the border stress concentration caused bycontact between rollers and inner. Furthermore, a certain load corresponds to a certainrange of optimal convexity value. Convexty value of rollers too large or too smallcould not reduce the border stress concentration, instead, cause the difference of stressbetween the ends and middle of roller, and weaken the uniformity of stress distributionalong the axis of roller.Based on contact stress analysis between roller and raceways, the explicitdynamic model of tapered roller bearing with logarithm profile has been established.The finite element simulation on the dynamic characteristic was carried out and thevariation of contact stress of bearing parts with time was studied. The geometricalshape of contact region between roller and raceways has an impact on bearing motionand stress distribution. Rollers produce serious vibration, which presented non-linearfeature. The difference of stress between the roller and cage is larger near the loadingregion. During the operation of high-speed train, temperature rise caused by frictionbetween rollers and inner of high speed railway have great effect on bearingperformance. In this dissertation, experimental study of temperature rise performancefor taper roller bearing with logarithm profile has been carried out on the special testdevice under different speed and load, in order to verify primarily high speedperformance of bearing. In the experiment, the testing machine and bearings runsmoothly, and the operating temperature of bearings rises as the rotation speed andload increases, and reached thermal equilibrium in a certain amount of time. Theresults showed that bearing of high speed railway coach met the initial designrequirements.In this dissertation convexity and dynamic performance of tapered roller bearingfor high speed railway coach have been analyzed. Furthermore, high speedperformance of bearing was validated through experiment. The study results couldprovide theoretical and experimental foundation for structure design of tapered rollerbearings for high speed railway coach.