Study On Thermal Failure And Mechanical Response Of Friction Pair In Wet Clutch

Wet clutch is one of the core parts of automatic transmission.Because of the advantages of high transmission efficiency,large transmission torque,good shifting comfort,and good heat dissipation,it has been more and more widely used.Due to insufficient machining accuracy,unreasonable structural design or the torque borne by the friction pair exceeds the torque capacity provided by the material,the friction pair is prone to early failure,which adversely affects the working performance of the wet clutch and the vehicle start jitter and shift impact performance.In this paper,the thermal instability analysis model of friction pair of wet clutch is established,the thermal failure mechanism of friction pair is analyzed,the influencing factors of thermal failure of friction pair are deeply studied,and the influence law of thermal failure of friction pair on its mechanical response is analyzed.The main research contents are as follows:The first chapter introduces the background and significance of the research topic.The structure and working principle of wet clutch,the form and influence factors of friction pair thermal failure are briefly introduced.The wet clutch research status at home and abroad are expounded.Finally,based on the shortcomings of the research,the main research contents and specific technical route of this topic are put forward.The second chapter studies the relevant theories in the sliding process of friction pair,and introduces the basic theories of heat transfer,thermos elasticity and thermo-hydromechanical coupling respectively.The third chapter analyzes the heat generation mechanism and heat transfer mechanism of friction pair in the process of sliding friction.The thermal instability analysis model of friction pair of wet clutch is established.The initial conditions and boundary conditions of the model are determined.A basis for the subsequent analysis of thermal failure mechanism and influence factors of friction pair is provided.The four chapter studies the failure mechanism of local hot spot,hot zone,warping deformation of steel plate and thermal wear of friction plate respectively.Based on the simplified model,the influence of working parameters,material parameters and structural parameters of friction pair on thermal failure is analyzed.The five chapter analyzes the main factors affecting thermal failure of friction pair,and the influence law of thermal failure of friction pair on its mechanical response under different slip speed and different thermal conductivity of steel plate is analyzed.The sixth chapter summarizes the main research results and puts forward the future research prospects.