Experimental characterization of frictional behaviour of clutch facings using Pin-on-disk machine

During the clutch engagement manoeuvre, sliding contact occurs between the pair of clutch facings mounted on the friction disk and the counter faces belonging to the flywheel and the pressure plate. The transmitted torque is proportional to the overall coefficient of friction which depends essentially on temperature, normal pressure load and relative sliding velocity. In this work, performance of the friction coefficient is investigated experimentally. Samples of a commercial clutch facings material have been tested using a Pin-on-disk apparatus. When the previous three parameters are preset constant, this machine provides automatic acquisition of friction coefficient and wear measurements. The obtained results are compared with the classical SAE J661a standard test. It is found that the actual clutch facings material has good fading resistance and a rather stable coefficient of friction once running in phase is achieved.