Dynamics Analysis Model Of High-Speed Rolling Bearings And Dynamic Performance Of Cages

High-speed rolling bearings are widely used in the aerospace field. For the high-speed rolling bearing, the light-load skidding and the instability of the parts are important failure mode. Particularly, the cage needs to be focused on. Practice and researches show that the bearing failure resulting from the skidding and instability of the cage accounts for 25% of the total failure of the rolling bearings in the aeroengine. Thus, the cage failure becomes a significant factor to the failure of the rolling bearing. The bearing cage design is based on dynamics analysis considerably, and the dynamics analysis of high-speed bearing cage is based on its dynamic model.Supported by the National Key Technologies R&D Program during the 11th five-year plan period and National Natural Science Foundation of P.R. China, the dissertation studies the dynamics models of the high-speed cylindrical roller bearings and angular contact ball bearings. Based on the model, the stability and skidding of the cage are studied sequentially. The contents of the dissertation are as follows:(1) The dynamic models considering the damping action are built for high-speed oil-lubricated cylindrical roller bearings and angular contact ball bearings. This study builds the acting force models of cages and rolling elements based on the models developed by Gupta, et al. Specifically, the study considers hysteresis and oil-film damping effects, and introduces the latest tribology formulae. Then, the dynamic equations of the parts (rolling elements, cages, rings) are developed through analyzing the forces and motion of the parts in a bearing in detail. As a result, the bearing dynamics model considering comprehensive factors is developed.(2) The analysis for the skidding and stability of the cage is investigated for cylindrical roller bearings and angular contact ball bearings. Based on the above bearing dynamics model considering damping, the effects of the load, speed, clearance, clearance ratio and the number of rolling elements on the cage skidding are investigated comprehensively. It is showed that there is a curvature like the valley for the cage slip rates from low speed to high speed process. In addition, the effects of operating conditions and design parameters on the cage stability (the cage mass center motion) are investigated comprehensively.(3) The method for evaluating creditability of the rolling bearing simulation system is given. The creditability is determined through calculating the similarity between the simulation results of the numerical bearing simulation system and test results of the physical test system. Particularly, aiming at the similar elements of the rolling bearing, a function is built up to calculate the similarity coefficient of similar unity. Besides, an improved method is given to determine the weight of the similar unity. This method overcomes the deficiency of the method comparing the possibility of fuzzy numbers. The latter may fail to determine the weight of the similar unity. Consequently, the method in the dissertation is proved through calculating the similarity between the numerical simulation data and physical test data of satellite momentum wheel bearing assembly.Finally, the corresponding software is developed, which is expected to provide theoretical basis and software tool support for the parameter design of the cages in high-speed rolling bearings.