Principal research areas on mechanical face-seals
Abstract A critical review of world literature on radial face-seals is presented in order to further understanding of seal operation and to obtain some elements of a design method for optimization of their performance. The principal areas examined are hydrostatic, hydrodynamic and boundary lubrication of the faces, and in particular cavitation and the influence of different constructive parameters on the dynamic behaviour of these seals.
Heat Generation Due to Friction in Dynamic Carbon Face Seals
Dynamic carbon face seals, used often in the aerospace industry, prevent the leakage of fluids between parts in relative motion. The two main performance parameters of dynamic face seals are leakage and life. The leading cause of premature dynamic carbon seal failure is destruction of the sealing interface by wear due to excessively high temperatures. This study uses basic thermal equations to examine the heat generation at a typical dynamic sealing interface. Finite element analysis is used to compare the steady-state and transient behaviors of the thermal system with variation of thermal properties and seal interface friction coefficient.
Dynamic Tracking of Noncontacting Face Seals
A model is presented here to predict the maximum frequency attainable for a typical noncontacting face seal (for gas service) to be run successfully in the presence of axial runoul. This work has been carried out because the determination of maximum allowable speed by laboratory testing results in serious and costly damage to seal rings. The circumferential variation in gas film thickness, spring load, seal gas pressure, and seal geometry are considered in estimating the applied torque to the stator enabling it to dynamically track the misaligned rotor. The mathematical expression arrived at shows that, for a fixed seal geometry, the maximum frequency is proportional to the square root of the closing force and inversely proportional to the square root of both axial runoul and mass. Calculations and laboratory experience available for testing the model, though very limited, are in reasonable agreement. Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference h...