Dynamic engagement characteristics of wet clutch based on hydro-mechanical continuously variable transmission

The effect of the design parameter on the clutch engagement process of the hydro-mechanical continuously variable transmission (CVT) was investigated. First, the model of the power train was developed with the software of SimulationX, and the clutch shift experiment was used to validate the correctness of the model. Then, the friction coefficient function was fitted with the test data to get the friction coefficient model suitable for this paper. Finally, based on the evaluating index of the friction torque and the friction power, two groups of design parameters (oil pressure and friction coefficient) were simulated and explained the changing regulation theoretically. According to the simulation results, the high oil pressure and friction coefficient can reduce the slipping time. The large oil pressure can increase the peak torque but the effect of friction coefficient on the peak torque is not so significant. The friction power reaches the maximum value at 3.2 s, the peak value increases as the oil pressure and friction coefficient increase. The effect of the oil pressure on the clutch engagement and thermal performance is greater than the friction coefficient.