Study On The Carrying Capacity For Cylindrical Roller Bearings Made Of New Materials

The bearing is one of essentially important components for the revolving machinery, whose carrying capacity and life length affect the machine performance directly. Thus, enterprises unceasingly strengthen its technical innovation and enhance its fatigue life and carrying capacity to maintain the technology superiority. But, there still has a large disparity in the bearing trade between our country and advanced countries. Therefore, more effort is needed to raise product technologies, design new bearings, and increase the life time and load capability of bearings, which could improve the international competitive power of our country.Although the exploitation of ceramic bearing could retrospect to the 60s of last century, the application of ceramic bearing was not widely recognized until the 90s of last century and the research on ceramic bearing is even more late in our country. A few technologies and design methods were obtained by the cooperation with overseas companies, and limited papers were published. Besides, the research of ceramic cylindrical roller bearing is less.Based on the academic research of high-speed cylindrical roller bearings, the famous finite element software named ABAQUS is adopted to analyze cylindrical roller bearings made of steel and ceramic materials, respectively in this paper. The finite element simulation indicates that the fatigue life of high-speed bearings is decided by the centrifugal force of rollers. Reducing the centrifugal force is an effective way to enhance the life time of bearings. For steel cylindrical roller bearings, when their rotation speed is -low or medium, their life-time is longer than those of ceramic cylindrical roller bearings and their reliability is higher than those of ceramic cylindrical roller bearings. But with the increase of rotation speed, the ceramic cylindrical roller bearings are superior to steel cylindrical roller bearings. These conclusions provide the useful reference for designing and using the ceramic cylindrical roller bearings.In order to explore the possibility of reducing the "Edge effect" of rollers by changing the roller edge material performances, the finite element software named ABAQUS is used to analyze the cylindrical roller bearings made of the functionally gradient materials in this paper. Firstly, the effect of the number of gradient material layer on the maximum equivalent stress is studied when Young's modulus of roller edge material is determined. The result indicates that proper number of gradient material layer can not only reduce the stress concentrate of the interface, but also reduce the roller's maximum equivalent stress. Secondly, the effect of different Young's modulus of roller edge material on the maximum equivalent stress is studied when the number of gradient material layer is determined. The result indicates that with the variation of roller edge material, the variation curve of the maximum equivalent stress is an approximate quadratic parabola, i.e., the roller edge material has an optimum parameter which makes the maximum equivalent stress of rollers minimum. Lastly, according to the finite element analysis results, the number of gradient material layer and the roller edge material property parameters are optimized for obtaining the optimum result. The possibility of reducing the "Edge effect" of rollers by changing the roller edge material performances is validated in this paper, which is an innovative work.