Thermal Mechanical Coupling Analysis And Temperature Prediction Model Research Of Wet Multi-plate Clutch

Many vehicles companies and research institutes research on hybrid cars more andmore deeply. But due to the great transmission torque and good thermal performancewet multi-plate clutch is widely applied in hybrid powertrain system. The paper focuseson the thermal mechanical coupling analysis of wet multi-plate clutch which belongs toISG single-motor hybrid powertrain system, and does a comparative study amongdifferent structure parameters, operating parameters of clutches and so on, as well asprovides the reference for structured optimization of wet multi-plate clutch anddevelopment of thermal management system. Main research contents of this paper areas follows:①First of all, the paper introduces power delivery model of hybrid powertrainvehicle, focuses on a detailed analysis and the introduction of working principles,characteristics, engagement process, and friction pair type and lubrication mechanismabout wet multi-plate clutch. Also, the paper establishes a dynamic model of engine,power transmission model of clutch and dynamic resistance model of road, andundertakes a comparative study between friction power and friction work producedunder the working condition of only engine drive or motor driven.②The paper elaborates on the basic theory of frictional pair heat transmission,deduces thermal differential equation and thermoelastic coupling theory; set upthree-dimensional finite element model of friction pair and carry out a six-sidedmeshing; The heat flux equation is derived, and heat flow is distributed according to theproperties parameters of friction plate and steel disc material; the paper dividesconvective heat transfer coefficient into three parts which are named friction groove,sweeping across plate, and inside and outside torus, respectively establishes convectiveheat transfer equation model; set the boundary condition of thermal borders, loads fromexternal force, constraints, and so on.③The dissertation makes an analysis of thermal mechanical coupling calculationof finite element about friction plate and steel sheet, focuses respectively on analysis ontemperature field in both friction plate and steel disc and stress field; compares andanalyses temperature field and stress field distribution law under different inside andoutside diameter difference of steel disc; does a comparative analysis of differentoperating parameters such as revolving speed difference, working pressure, and engaging time of wet multi-plate clutch, lay the foundation for the establishment oftemperature prediction model and thermal management model.④The paper makes an overview of temperature prediction model and thermalmanagement model on wet multi-plate clutch, uses the maximum temperature value offinite element analysis under different operating parameters, and sets up a predictionmodel of friction pairs temperature; presents the simulation analysis of thermalmanagement system for vehicle powertrain system.The thermal mechanical coupling analysis method of wet multi-plate clutch used inthe dissertation provides reference for clutch friction pair coupling analysis. Moreover,different parameter models analysis lays the foundation for structure optimization of thewet clutch and the establishment of thermal management system.