Research On Thermo-Elastic Coupling And Vibration Damping With Modification Of Helical Gear System

With the continuous development of industrial technology, high speed and heavy power gear system has been widely used in many fields, such as transportation, aerospace, shipbuilding. However, the thermal behavior and vibration noise of gear transmission has become the focus of the present study. The paper research subject is high-speed rail traction gear system. The thermal behavior includes distribution of bulk temperature and contact surface flash temperature, thermal deformation, thermal elastic coupling analysis, are studied based on the theory of tribology and Hertz contact theory. It provides the basis for the modification design of gear system. Finally, the influence of different amount of modification on the vibration response of the gear system is studied by numerical analysis method to determine the optimum modification amount. The main research contents are as follow:(1) Based on ANSYS-APDL parametric modeling method, the meshing model of helical gears with different amounts of tip relief is established, which is the basis of the load contact analysis, thermal deformation analysis and thermos-elastic coupling analysis of gear teeth.(2) The distribution law of temperature field of gear system is studied based on Hertz contact theory and principle of tribology by means of finite element method. The formula of friction heat flow on the meshing surface is deduced according to the equation of meshing surface contact pressure, relative sliding speed and contact surface friction coefficient. The convective heat transfer coefficient of gear tooth surface is obtained under the consideration of the methods of lubrication and the parameters of the lubricating oil. The frictional heat flux and heat transfer coefficient are applied to the surface of the wheel body as a thermal load, and the distribution law of the temperature field is obtained by using the finite element method.(3) The thermal deformation and thermo-elastic coupling of the gear system is calculated by means of the finite element method based on the results of gear bulk temperature field. The structure analysis of the gear system is analyzed. The influence of temperature field on contact characteristics of gear system is studied by comparing the results of gear deformation and stress distribution and transmission error distribution in structure analysis and thermal elastic coupling analysis. The parameters of tooth profile modification are determined by considering the thermal deformation of gear system. The distribution results of temperature field and thermal elastic coupling analysis were compared before and after modification.(4) The distribution of the transmission error and the distribution of the meshing stiffness under different parameters are obtained based on the results of thermo-elastic coupling analysis. The dynamic model of parallel shaft helical gear rotor system with 12 degrees of freedom is established by the method of shaft end unit. The time-varying meshing stiffness considering the amount of tip relief was introduced into the system dynamics model, to research the influence rule of vibration response of helical gearing under the different amount of tip relief It provides the basis for the determination of the optimum modification amount.