Elimination of Off-Design Operating Modes for Multiplate Clutches of Vehicle Transmission 2022-01-5012

Cases of destruction of multiplate clutch elements were faced when carrying out tests of the vehicle transmission, which appeared during a limited trial time. The results of the computational and experimental study for the occurrence of off-design modes when shifting gears associated with the level of filling of the compensation and piston chambers of the multiplate clutch are presented. The objective of the study is to improve the accuracy of the implementation of the required law of control of transmission clutches by purposeful regulation of the volume of working fluid in the compensation chamber of the hydraulic cylinder for the clutch control. A road testing procedure was developed for the reproduction of the conditions for the appearance of the operating mode under investigation. Based on the procedure, an objective assessment was carried out to evaluate the transmission functioning and the modes of vehicle movement. The developed mathematical model of the piston stroke for the engaging clutch allowed for assessing the dependence of the shifting quality of control law realization on the following parameters: level of filling of the compensation chamber, features of the solenoid valves operation, the stiffness of the return spring, and the number of plates in the clutch. Based on the computation of a complex dynamic system, the required volume of transmission fluid in the compensation chamber of the multiplate clutch was determined. It was defined in dependence on the piston stroke and the inner diameter of the oil ring. In this work, the technical solutions for stabilizing pressure in the compensation chamber are proposed and implemented in the design. This allowed excluding the occurrence of the off-design mode.