Thermo-solid Coupling Analysis Of High Speed Gear Transmission System

With the development of modern industry,gear transmission has been widely used due to its high transmission efficiency and stable transmission,and the requirements for gear performance are also getting higher and higher.The gear can generate a lot of heat in the transmission,causing the change of the gear temperature and the change of the performance of the lubricating medium,thus changing the characteristics of the gear transmission.Studying the performance of gear transmission systems by studying the thermal behavior of gears and the performance of thermal elastohydrodynamic lubrication becomes a wider trend.The reasearch subject in this paper is a pair of high-speed gears.The thermal behavior of gear transmission,lubrication characteristics and scuffing load capacity are analyzed and calculated based on Hertz contact theory,heat transfer theory and thermoelastic lubrication theory.The influence of thermal behavior and lubrication characteristics provides a basis for the selection of working conditions for high-speed and heavy-power gear transmission system.The main research contents of the thesis are as follows:1.The contact pressure of the gear tooth surface is calculated Based on the Hertzian contact theory.The friction coefficient between the tooth surface,the absolute sliding speed and relative sliding speed of the meshing gears and the magnitude and distribution of the frictional heat flow are analyzed.The analytical calculation method of convective heat transfer coefficient is given,and the influence of the speed and torque on the frictional heat flow and related parameters is summarized.2.The three-dimensional model of the gear is established.The finite element simulation software workbench is used to analyze the body temperature field of the gears.The temperature distribution curve of the main and driven wheels is obtained.The influence of the speed and torque on the body temperature field of the gears is quantitatively analyzed.3.Based on the known temperature field of the gear body,a mathematical model of linear contact thermoelastic lubrication including basic equations such as Reynolds equation,film thickness equation and energy equation is established.The multigrid method is used to solve the problem.Oil film pressure,oil film thickness and oil film temperature distribution,and the influence of input speed and torque on gear lubrication characteristics were studied.