Investigation on the thermodynamic characteristics of the deformed separate plate in a multi-disc clutch

This work is devoted to investigate the thermodynamic characteristics of the deformed separate plate in a multi-disc clutch. The thermodynamic model is proposed, and the contact ratio of mating surface is varied to imitate the deformed plate. Moreover, the experimental study is conducted on the clutch test bench; in order to induce the plate deformation more easily, the thermometric plate has experienced the circumferential elastic deformation before experiments. Before the elastic deformation of separate plate occurs, the surface temperature increases steadily and the friction torque increases slowly with the increase of coefficient of friction. When the temperature gradient in the circumferential direction reaches the critical value 2–3 °C, the elastic deformation is excited. In the process of elastic deformation, the temperature growth rate in the contact zone increases dramatically, and the friction torque rises steeply. As for the variation of friction torque after the elastic deformation, it can be divided into three categories: increase smoothly, stable and decrease gradually. Moreover, at this stage, the smaller the contact ratio is, the higher the temperature in the contact zone is, and the greater the friction torque is. Meanwhile, with the decrease of the radial length and circumferential angle in the contact zone, the radial and circumferential temperature differences of the plate expand dramatically. The conclusions can be used as a theoretical basis for evaluating the real-time status of friction components and diagnosing the clutch failure.