Performance of Various Shaft Seal Dust Lips in a Dust Environment and Their Ability to Form a Vacuum Between the Primary and Secondary Lips

Contamination of sealed systems from the outside not only affects the performance and life of a sealed mechanism, but also that of the seal itself. Many dust and dirt exclusion systems have been offered by manufacturers, including various radial and axial auxiliary lips. The tests described in this paper investigate the effect of several auxiliary dirt lips on seal life in a dust environment. Since many of these designs provide interference to the shaft for both primary and secondary lips, the tests also examined vacuum formation between the lips and its effect on the seal.