In practice rotary shaft seals will experience a small-amplitude dynamic excitation. It is shown that under periodic excitation circumferentially nonuniform clearances develop due to viscous seal material behaviour. The nearby fluid will fill these gaps, so entrainment and squeeze effects can develop fluid pressures, which are sufficiently high to overcome the radial preload. Viscous seal properties are essential in this type of EHD lubrication. Hence it is designated viscoelastohydrodynamic (VEHD) lubrication. At present, this lubrication concept is the only macrohydrodynamic theory that explains the existence of a consistent circumferentially nonuniform film geometry of appreciable dimensions. Moreover, calculated values of film thickness and friction are in agreement with experimental data.
|Title of host publication||Vehicle tribology : proceedings of the 17th Leeds-Lyon symposium, held in Bodington Hall, the University of Leeds, England, 4-7 September 1990|
|Editors||D. Dowson, C.M. Taylor, M. Godet|
|Place of Publication||Amsterdam|
|Publication status||Published - 1991|