Study On Nonlinear Contact Analysis And Tooth Modification Of Heavy Load Hub Reducer

With the development of our country's economy and the continuously development of the transportation industry,the demand for the truck's load capacity and performance is getting higher and higher.At present,hub reducer with planetary gear transmission is widely used in the wheel driving axle of domestic and foreign truck.It is also used in the new energy electric vehicle wheel side drive technology,the hub reducer gear transmission performance requirements are also getting higher and higher.Therefore,the study of the dynamic characteristics of the gear transmission system is of great significance to reduce vibration and noise,improve the stability and bearing capacity of the transmission and prolong the service life.The study on the bearing capacity of gear drive reducer encountered in the actual use of the process for the wheel,transmission stability and tooth damage and other problems,based on the finite element results and combining with actual problem analysis,put forward the necessity of gear modification and the comprehensive modification scheme for the drum axial tooth modification of the sun gear and the modification of the tooth profile of the planet gear are obtained,providing certain reference significance for the improvement of the future.The main work contains:(1)An overview of the structure and working principle of the hub reducer is introduced,then according to involute equation,the application of parametric design method,the gear planetary gear transmission model is established,and combined with the assembly interference free transmission principle,providing the basis for subsequent analysis of geometry.(2)Contact model of two cylinder roller is carried out using finite element analysis theory and Hertz contact theory,in order to verify the accuracy of finite element contact analysis and validity,providing reference for gear contact analysis.According to the structure characteristics and working principle of the wheel reducer,finite element analysis of planetary gear train in a static contact on the sun wheel and planetary wheel,considering the tooth friction,found that the finite element simulation analysis results in good agreement with the theoretical analysis,obtained the contact interval meshing position,variation law of friction the change factor of static contact stress,pointed out the importance of reasonable control of lubrication.(3)According to the principle of relative motion,implicit dynamic finite element method based on the sun gear and planetary gear dynamic contact analysis,analysis of the dynamic contact stress and equivalent stress variation and stress distribution along the tooth width is carried out.According to the actual conditions of the wheel side reducer,the effect of friction,load torque and rotational speed on the dynamic contact performance of the gear is analyzed,which provides a reference for the improvement of the transmission performance.(4)Based on the consistency of the results of finite element analysis and actual problems of hub reducer gear transmission,for the improvement of meshing impact,the longitudinal load,edge stress concentration,in order to improve the bearing capacity and transmission stability,prolong the service life,we applied drum axial tooth modification to the sun gear and tooth profile modification to the planetary gear with comprehensive modification measures,and the dynamic performance before and after modification were compared.It was found that after the practice,maximum contact stress of tooth surface decreased by about 17.2%,the maximum equivalent stress is decreased by about 11.3%,decreasing the meshing contact,the maximum tooth surface contact stress and the equivalent stress curve are relatively smooth,avoiding the stress concentration;dynamic contact force should alleviate the edge effect,the tooth width direction stress distribution is improved,the bearing capacity is improved;the transmission output relative error and changed little.The utility model has the advantages of low dynamic vibration,stable transmission,low noise and long service life.The practical effectiveness of the comprehensive modification method is illustrated.