Research on Critical Open and Close Pressures of an Oil Discharge Valve for High Speed Wet Shifting Clutch

For the imperfect discharge of oil in the piston chamber during the rotation of wet clutch at a high speed, a centrifugal oil discharge valve structure is researched. A mathematical model of oil discharge valve is established based on the force analysis, and the movement process of steel ball in oil discharge valve is analyzed. A test system for wet clutch system with oil discharge valve is developed. The critical open and close pressures of the oil discharge valve are studied through experiment. The simulated and experimental results show that the oil discharge valve can effectively discharge the remaining oil in the piston chamber when the wet clutch separates at a high speed, and the critical open and close pressure features of the oil discharge valve are obtained. The critical open and close pressures increase with the increase in the tilting angle of valve body, α, and the radius of steel ball, r_b. According to the changing feature, a computing method for calculating α and r_b from the minimum value of critical open pressure and the maximum value of critical close pressure is proposed.