Abstract: The dynamic analysis model and the mathematical model of the friction torque of thrust ball bearings are obtained based on the dynamic theory of rolling bearing. The effects of the structural parameters and operating conditions on the frictional torque of thrust ball bearings are analyzed and verified. The results show that the friction torque caused by spin-sliding is approximately 70% of the total friction torque of the thrust ball bearings. From the perspective of the design of the thrust ball bearings, the friction torque can be reduced by increasing the number of balls and the cage pocket clearance appropriately on the premise that the stability of the cage can be ensured. However, the priority should be given to the number of balls, which has more obvious effect on the friction torque and minimal influence on the bearing structure. With the increase in groove curvature radius coefficient of shaft (house) washer, the bearing friction torque decreases in exponential form. The groove curvature radius coefficient of shaft (house) washer has a little effect on the friction torque when its value is over 0.56. In consideration of the bearing carrying capacity, the groove curvature raidus coefficient of shaft (house) washer is better between 0.56 and 0.58. From the perspective of the use of the thrust ball bearings, the capsized moment, impact load and rotation speed have great effect on friction torque, but the influence of the impact load on it is the worst.

Key words: mechanics, thrust ball bearing, dynamic analysis model, friction torque