Modeling And Experimental Analysis On Friction Torque Transfer Of Wet Clutch

Based on wet shift clutches assembled in the high power transmission, this paper focuses on the friction torque mathematical models of single friction pair. The working process can be divided into two phase : idle actuating time eliminating initial design gap and actuating time exciting surface friction. The clearance variation model and the mathematical model of friction torque are built respectively. Experiments are also conducted to verify the correctness of the model. The main contents are as follows:First, by simplifying wet clutches into single friction pair, oil charge model was built to work out the behaviors of oil pressure and piston displacement. The clearance variation of disc and flat steel friction pairs was presented when the effects of elastic system and oil dynamic pressure on the gap model were taken into account.Second, the variation characteristics of viscous torque was solved in the eliminating phase of initial clearance. Meanwhile, the contraction of lubricating oil film in the actual conditions was analyzed. The calculation models of viscous torque of rough contact torque of disc and flat steel friction pairs were developed during engagement, together with variation characteristics of viscous torque and friction torque.Third, influences on friction torque of wet clutches were studied. The influencing factors such as lubricating oil flux, inlet and outlet pressure drop and rotation speed difference were analyzed in the eliminating phase of initial clearance.What’s more, contact pressure and rotation speed difference during the engagement of friction pairs were analyzed.Fourth, the clutch comprehensive test bench was set up so as to test changes of controlling oil pressure, revolving speed and friction torque. Viscous torque and tough contact torque were analyzed. The results proved the correctness of calculation model.