Experimental investigation of transient thermal characteristics of a dry friction clutch using alternative friction materials under different operating conditions

The thermal characteristics of four types of dry friction clutch materials (LUK, G95, HCC, and Tiger) are investigated experimentally and numerically in the present work under different working conditions; such as initial sliding angular velocity (omega(ro)), torque (T), and sliding time (t(s)). The temperature distributions over a cross-section of friction clutch elements (pressure plate and flywheel) are investigated and optimized during the sliding period (heating phase), and full engagement period (cooling phase). The effect of alternative frictional materials lining of a clutch disc on the thermal behavior of the sliding system under different operating conditions (different angular velocities, torques, and sliding periods) is investigated experimentally. The results showed that the maximum effect on the temperature values occurred when applying maximum torque (4.5 kg.m), maximum initial rotational speed (1200 rpm), slipping period (30 s). However, the temperature values at interface contact decrease when decreasing all the above input conditions values to (2.5 kg.m, 690 rpm, and slipping period to 8 s). The results showed that the temperature reduced (53%) from (180.4 degrees C) for applied torque 4.5 kg.m with initial rotational speed (1200 rpm) and slip period (30 s) to (83.3 degrees C) when applied torque 2.5 kg.m, initial rotational speed (680 rpm) and slip period (8 s) for clutch disc (LUK). It was obtained the same behavior for the other three discs (G95, HCC, and Tiger), but with different values of temperatures. The results show that the temperatures of the pressure plate interface (T-max = 159.1 degrees C) are higher than those at the flywheel interface (T-max = 152.7 degrees C), due to the low thermal capacity of pressure plate compared to the flywheel when using G95 frictional material. The experimental optimization results showed that the highest temperatures were obtained when using friction clutch disc (LUK), and minimum temperature when using (HCC) disc, around (20%) reduction when replaced (LUK) material with (HCC) under the same working conditions (T = 4.5 kg.m, omega(ro) = 1200 rpm, and t(s) = 30 s).