Influence Of Spline Friction On Engaging Process In Wet Multi-disc Clutches

Wet multi-disk clutches are one of the key components in vehicle transmission systems.The performance and design level of clutches directly determines the performance of transmission system.There is a certain gap between design life and real life of wet multi-disc clutches for the presence of the inaccuracy of wet clutch model.Taking the spline friction of friction pairs into account,the mathematical model of friction torque during steady state and slipping process and dynamic model of transmission systems are developed,with the influence of working parameters on torque response.Moreover,the experiments are conducted to validate the model reliability.The main contents were as follows:(1)On the basis of the force analysis of a single friction pair,the pressure decay was calculated and the torque model considering spline friction was established to investigate effects of material parameters and structure parameters on torque model.(2)According to hydrodynamic lubrication theory and GT asperity contact model,the torque model without considering spline friction of wet clutches was acquired during the process of slipping,as well as the nominal film thickness,asperity pressure and total torque.Analytical results were validated by test data from clutch test rig.(3)The difference of clutch engaging characteristic was compared whether spline friction was considered or not.The influence of torque and power loss taken by working parameters such as pressure,initial angular velocity of drive end,inertia of driven end,static friction coefficient and number of friction pairs was analyzed.(4)A clutch test bench was set up to study the influence of pressure,speed difference and lubrication on friction temperature.The results of experiment verified the correctness of mathematical model.