Tapered Roller Bearing Contact Mechanics Characteristics Analysis And Optimization Design

Tapered roller bearings withstand radial and axial loads,have high load-carrying capacity and rotational accuracy.Therefore,they are widely used in the machine tool industry.As a component of the speed box of a high-speed rail and automobile,its performance directly affects the performance of all equipment,so there are very high standards of bearing reliability.The study of bearing contact stresses,load distribution and contact stiffness is of great importance to improve the performance of tapered roller bearings.The main contents of the study and the conclusions of this paper.（1）In this paper,tapered roller bearing 30206 is considered as an object of study,its structural characteristics are introduced,the force balance of each roller is analyzed,the relationship between the roller and the deformation is investigated,and the expression of the stiffness of roller-raceway contact is obtained.Discuss the load distribution of roller under different clearance,get the influence law of clearance on bearing load distribution,and find that whether positive clearance or negative clearance,as long as it exceeds the limit value of bearing will reduce the bearing bearing capacity,choose the suitable clearance can improve the bearing capacity.（2）Based on the linear contact theory of Hertz,the finite linear contact length problem of a tapered roller bearing is studied,and the distribution of contact stresses between the roller and raceway of a single roller and the entire series of rollers under various loading conditions is obtained.Finite element analysis was used to simulate the bearing under radial load.The results show that the law of influence of load on bearing contact stress is nonlinear,and the correctness of numerical solution is confirmed by simulation results.（3）The experimental scheme is designed and the test rig is built to perform elastic deformation tests on the tapered roller bearing to verify the accuracy of the stiffness calculation equation.The experimental data and the numerical solution are analyzed and compared to obtain the stiffness values of the actual bearing.Through data comparison and verification,it is found that the deformation obtained from the test is slightly higher than the numerical solution,but the deviation of the value is within the error range,which verifies the feasibility of the stiffness expression.（4）Study a method for calculating the fatigue life of bearings and obtain an expression for calculating the fatigue life of bearings based on the S-N curve of the material.The optimum fatigue life of the roller is taken as the target to optimize the roller convexity,and logarithmically modified H-T curve at different control parameters are calculated by finite element analysis,and the effect of the law of different convexities on contact stresses and fatigue life of the roller and raceway is analyzed.Taking the best fatigue life and contact stress as the criterion,we get the best logarithmic modified curve with profile curvature coefficient k₁=1.5 and convexity amount z_m=0.008 as the control parameters,the fatigue life is 7.49×10⁹ cycles.