Operation of Radial Lip Seals on Roller-Burnished and Other Shaft Surface Finishes

The shaft surface upon which a high performance radial lip seal operates is the second most important element of a sealing system, second only to the seal itself. For many years the standard specification for shaft surface finish or texture was “0.25 - 0.50 μm Ra plunge ground with no machine lead”. Since this has been a costly and difficult process to create and control for many applications, other shaft processing methods have been used. This paper outlines the initiation of a study to evaluate the performance of radial lip seals on a variety of shaft surface finishes. The converter hub or front pump seal application has been selected for this study due to the unique shaft finishing processes incorporated.