Research On The Critical Stick-slip Characteristics Of High-temperature Rolling Bearing

Stick-slip is one of the important factors of rolling resistance, especially to the deep groove ball bearings. When the rolling bearings are running, the contact point of contact region will produce stick-slip phenomenon. The stick-slip characteristics at normal temperature and high temperature of the rolling bearings have been researched in the paper when make SKF6206 deep groove ball bearings as the object of the research.Firstly, a new Heathcote stick-slip model of bearing balls has been developed based on both Hertz theory and materials Young's modulus and used to calculate the stick-slip values at contact region for different of bearing materials and to analyze their stick-slip characteristics by means of the model and finite element method. And based on the model and the finite element method, the influence of roll bearings' stick-slip characteristics exerted by materials matching has been studied. The effect of roll bearings'stick-slip characteristics produced by the rollers match with inside and outside tracks with different materials has been analyzed. For example, when Si3N4 and GCr15, as rollers, used to match with the same inside and outside track's materials of bearings, the major and minor axis of the contact region Si3N4 roller with outside track of bearings decreases 8% then that of GCrl5, the value of the stick-slip maximum point of contact deformation decreases 11% due to the Young's modulus Si3N4 being larger then that of GCr15.Secondly, by the use of thermal analysis unit of finite element analysis, established a thermal-structural coupled analysis model of high-temperature bearings, derived calculation expression of Heathcote stick-slip amount at different temperatures and calculated the variation of stick-slip of rolling contact region when use different match vices. The evolutions of the stick-slip at two cases of the rolling bearings at different temperatures have been analyzed. One is that the materials of inside and outside tracks are the same but the materials of the rollers are different. The other is that the materials of inside and outside tracks are different but the materials of the rollers are the same. And clearance is an important factor to the accuracy of high temperature rolling bearings.Finally, when the temperatures are different, the variation of the stick-slip amount of the rollers and the tracks and the friction phenomenon generated by stick-slip have been investigated; and also investigated the features of high-temperature bearings'stick-slip curves and their effect on the regularity of resistance. It revealed that rolling resistance increase obviously when the temperature reaches at 200℃, and as a result of this the critical work temperature is 200℃when the material of bearings is in common use of high-temperature bearings.