Analysis and Modeling of the Topography of Mechanical Seal Faces

The aim of this article is to provide some relevant statistical parameters for mechanical seal faces and to present some methods of modelling them in order to study mixed lubrication. Three mechanical seals with faces of three different material combinations were analyzed at three operating times (unused, run-in, and worn). Surface roughness and waviness were analyzed. Generally speaking, the amplitude of the waves tends to increase with time, whereas roughness height shows the opposite trend, except in the case of the hard faces combination. The seal surfaces are extremely skewed, this phenomenon being enhanced by wear. The surfaces are nearly isotropic with a slightly higher correlation length in the sliding direction. Two models with two different autocorrelation functions (ACFs) were used to simulate surfaces. These models, based on the Patir approach (Patir (1)), used the Johnson translation curves to impose non-Gaussian height distribution. Even if the models are able to reproduce experimental tende...