Multiscale Contact Mechanics with Application to Seals and Rubber Friction on Dry and Lubricated Surfaces.

Fluid leakage out of mechanical equipment such as gearboxes, hydraulic systems, or fuel tanks could cause serious problems and thus should be avoided. Seals are extremely useful devices for preventing such fluid leakages. We have developed a theoretical approach for calculation of the leak rate of stationary rubber seals and the friction force for dynamic seals. The theory is based on a recently developed theory of contact mechanics, which we briefly review. To test the theory, we have performed both simple model experiments and experiments on engineering seal systems. We have found good agreement between the calculated and measured results, and hence our theory has the potential to improve the future design of efficient seals. We briefly review the processes that determine rubber friction on lubricated smooth and rough substrate surfaces. We present experimental friction results for lubricated surfaces, obtained using a simple Leonardo da Vinci setup. The data is analyzed using the Persson rubber friction and contact mechanics theory. [ABSTRACT FROM AUTHOR]