The Quality of Shaft Surface

To work and a satisfying life effectively, the oil seals must have a thin oil film between lip and sealing intermediate shaft pin. This condition, known as hydrodynamic lubrication needs wave surfaces that are not perfectly smooth, but to help hold the microscopic pockets of the lubricating film. Although most diving grinding is largely used to end seal journals, the resulting surface is not optimal from this point of view.

Under a magnification of the surface is closely spherical bulges with valleys between them. The spherical lobes provide an extremely smooth surface for the turn of the sealing lip against, while the valleys retain lubricant and to promote hydrodynamic lubrication. Tests show that area of ​​four to five times the lifetime of the seals increases when compared plunge ground waves.

Other methods of treatment such as shot blasting and liquid honing, offer a matte-like surface, which is generally more effective than the surface of the soil leap. But often lifted leave these methods, sharp edges that separate the microscopic holes resulting still provide possible starting points for leaks.
A sealing-log surface which has a hammered texture reversed, with relief (instead of indented) between spherical bulges and corresponding valleys supports improved hydrodynamic lubrication. EFA has developed a method that compresses the seal between the rolling dies magazines that were recovered at random to create spherical indentations. This leaves an "orange peel" texture on the surface of the pins, typically 20 to 40 m.