Elastohydrodynamic Lubrication with Wear and Asperity Contact in Mechanical Face Seals.

摘要

In this report lubrication effects caused by waviness in contacting mechanical face seals are investigated. A lubrication model is developed which includes the effects of hydrodynamic lubrication in conjunction with asperity contact, asperity contact pressure A lubrication model is developed which includes the effects of hydrodynamic lubrication in conjunction with asperity contact, asperity contact pressure, elastic deformation of the seal rings, and wear of the surfaces. Several sources of initial waviness are considered. Based on a one dimensional model, it is shown that some amount of hydrodynamic load support can be expected to occur in a water seal even though there is a considerable fraction of rubbing contact. As the fraction of load supported by hydrodynamic pressure becomes greater, the average wear rate will become smaller. Thus any parameter changes which cause greater hydrodynamic support are desireable. It is shown that there exists an optimum initial waviness and face width to maximize hydrodynamic load support. It is also shown that lower values of surface roughness lead to higher load support. Time dependent effects are obtained by including wear in the model. It is shown ethat most initial waviness will wear away under steady state operating conditions, and thus hydrodynamic load support will decrease with time. Neither thermal effects nor friction effects alter this behavior. However, a variable sealed pressure may lead to a stable or increasing fraction of hydrodynamic load support.