Abstract:

The drag torque can reduce the transmission efficiency of the wet clutch， shorten its service life and reduce its working reliability. At present， most of the research on the drag torque of wet clutch is based on the average gap distribution model， but the gap distribution between the friction pairs has an important impact on the drag torque， and it is difficult to obtain the gap distribution of each friction pair of wet clutch in working state. Therefore， this paper proposes a simulation method for the clearance distribution of friction pairs in the wet clutch， in which the order statistics method is used to simulate the position of each friction plate and steel plate to obtain the initial clearance distribution law of each friction pair. On this basis， the critical rub-impact speed and drag torque of the unconstrained friction pair system under different working conditions are analyzed by simulation， and verified by test. The results show that when the total clearance of the wet clutch is constant， the critical rub-impact speed of the unconstrained multi friction pair system is less than the critical rub-impact speed based on the assumption of average clearance distribution. With the increase of the total clearance of the wet clutch， the critical rub-impact speed decreases gradually. The drag torque of the unconstrained multi friction pair system is significantly greater than that based on the assumption of average clearance distribution. With the increase of the total clearance of the wet clutch， the drag torque gradually decreases.

Key words: wet clutch, unconstrained friction pair, drag torque, critical rub-impact speed