Tribology of flexible seals for reciprocating motion

The dynamic behavior of oil films formed between a band-shaped nitrile rubb er specimen with a D-shaped or lip-shaped cross section and an oscillating glass plate is directly observed by means of the mono-chromatic optical int erferometry technique. The friction force is also measured. The effects of he cross sectional shape of the seal and the length of the stroke on the fi lm formation and friction characteristics are discussed together with the e ffects of surface defects. On the basis of analyses of experimental data, t he conditions which bring about the film collapse are clarified. It is also claimed that the distinction of lubrication modes by the Stribeck curve mi ght be reconsidered. [S0742-4787(00)02304-3].