Conclusion
Mechanical face seals. Hydrodynamic and mixed lubrication

When the surfaces of a mechanical seal are no longer parallel and immobile, the lubrication regime is hydrodynamic. The Reynolds equation, which governs the pressure in the lubricant film, has no analytical solution in the general case, and it is therefore necessary to develop dedicated numerical calculation codes. However, certain approximations are justified and allow us to establish analytical solutions. Using these, the hydrostatic and hydrodynamic effects of pressure generation in the lubricant film and the forces exerted by it are highlighted. Hydrodynamic lift cannot exist without cavitation. Furthermore, the hydrodynamic moment due to the misalignment of the faces tends to rotate the axis of the misalignment of the floating element, thus avoiding contact between the faces.

Mixed lubrication optimizes the compromise between friction and leakage. The theoretical...