Non-Leaking Lip Seals: A Roughness Effect Study

An analysis of roughness effects on leakage of lip seals is presented. The generation of fine axially oriented striations has been seen to occur on some lip seals after a certain time of operation, Mu¨ller and Ott (1984). Kammu¨ller (1986) and Mu¨ller (1987) have suggested that under running conditions, the striations may be distorted due to differential shear stresses leading to a channelling or pumping action of the grooves. This may balance the flow due to the pressure difference over the seal and thus suppress leakage. The roughness theory of the first author has been combined with the roughness pattern distortion theory of the second author. The resulting model is seen to predict a complete leakage suppression under realistic conditions.