Friction in a hydraulic motor piston/cam roller contact lined with PTFE impregnated cloth

The aim of this work was to test a new PTFE impregnated cloth material for use as a surface layer on the pistons of a hydraulic motor at the interface with the cam roller. Tests were carried out using a standard Bowden & Leben sliding friction tester which indicated that the cloth material gave similar results to the current material (PTFE impregnated sintered bronze) in both dry and lubricated conditions. Actual component tests run on a modified twin disc test machine showed that the cloth performed better in conditions of reduced lubrication. Wear testing would be required to fully assess the feasibility of using the material in a hydraulic motor.