Dynamic Sealing Mechanism
The Dynamic Sealing Mechanism or pumping action is how the fluid film created from the Hydrodynamic Effect is maintained without developing a leak. The pumping direction is a direct correlation to an asymmetrical contact pressure profile. This pressure profile is controlled by designing the proper oil side angle, air side angle, and spring offset distance. For the pumping action to work needs to be larger than. This creates a larger pressure gradient on the oil side. The garter spring is offset to the air side and helps maintain the air side angle. The result of properly controlling these design parameters is an asymmetrical contact pressure profile. When this profile is combined with microasperites in the seal lip’s contact width, a net pump rate in the direction of the oil reservoir is created, therefore preserving the leak free fluid film created by the hydrodynamic effect.