Numerical Simulation Of Contact Characteristics Of Ball Bearing Based On Thermomechanical Coupling Model

Rolling bearings are commonly used machine elements because of their excellent characteristics such as low friction movement, less power consumption, easy maintenance and long lifespan. Along with the rapid development of industrial technology, the performance of rolling bearing is becoming even higher. The study on thermal-fluid coupling, thermal-mechanical coupling, as well as dynamic analysis of rolling bearing is currently a hot research.The thesis subject is supported by National Natural Science Foundation. Combining with theory of hydrodynamics, heat transfer, contact mechanics, and structural dynamics, the multi-body static contact characteristics, contact heat transfer and dynamic contact characteristics are studied for high speed rolling bearing system.The research work presented in this thesis can be summarized as follows:1) Discussion on the form of finite element mesh in bearing contact model. By finite element analysis of multi-body static contact problem, the displacement, stress and strain fields under the radial load are obtained.2) Using the ANSYS parametric design language (APDL), the command stream for optimizing raceway's curvature of rolling bearing is compiled based on the model of single rolling element contacted wih raceway. The first order method is used to implement the optimization design under the conditions of enough strength. The optimization results shown the elastic deformation be reduced.3) Establishing a thermal-fluid coupling model of lubricating oil, the distribution of temperature and flow fields are obtained. Combined with the thermal boundary conditions of thermal-fluid and the structural boundary conditions, the thermal-mechanical coupling model is built to simulate the contact characteristics of rolling bearing. The contact stress and deformation between raceway and rolling elements, as well as the bearing temperature are obtained. Frictional heat of rolling bearing had an considerable impact on deformation and contact stress, by comparasion of analysed results when considered thermal effect or not.4) Considering the effect of the radial load and rotational speed of bearing, the finite element model for dynamic contact problem of ball bearing is established by the software of ANSYS/LS-DYNA. Using explicit dynamic finite element method, a dynamic contact analysis of the ball bearing is made under the same radial load and different rotational speeds imposed on inner ring, and the dynamic response of bearing and the stress distribution of the rolling element during the running process is obtained.5) By the language of Java and ANSYS/APDL, a finite element modeling and anlysis program is compiled to create the parameter model, generate mesh, determine the boundary conditions and display results of ball bearing. Using it, the finite element model can be established quickly, and the static/dynamic contact analysis and thermal-mechanical coupling calculation can be completed conveniently by the help of the software of ANSYS. The analysis results show the accuracy of this program.