Tribological behaviours of bronze-filled polytetrafluoroethylene dry journal bearings

Most laboratory investigations on the tribological behaviours of polymers are done on the rigs which are in Line with pin-on disc or pin-on ring models. But bearings have special geometrical and kinematical characteristics. That is why obtained results can only give a rough idea. In this study, the effects of sliding distance, bearing pressure, the medium and low speed on friction and wear in journal bearings made of 60% bronze-filled PTFE composite are experimentally examined. The results of experiments are presented in tables and graphics which proves that the coefficient of friction and the wear are strongly influenced by the thickness and composition of these films depending on the adhesion between steel and composite surfaces, the cohesive properties of the polymer used, pressure and the sliding distance. Taking into consideration the high number of factors, and their widely fluctuating characters and effects on the friction and wear, an optimum bearing construction may only be achieved through experiments. (C) 1999 Published by Elsevier Science S.A, All rights reserved.