Keeping 'Lips' Sealed: Increased Speed and Pressure Put a New Spin on Shaft Seals

摘要

In a continuing effort to bring the latest seal technology to market, Simrit has developed a PTFE lip seal for use in high-speed and high-pressure environments. Using patented lip geometries, these seals feature a unique elastomeric-backed PTFE lip that allows the seal to function under pressures and speeds that can cripple traditional seal designs. Typical applications include gearboxes, superchargers, vacuum pumps, fuel injection systems, and crankshaft seals. Some of the benefits of the PTFE lip seal are: · A rubber O.D. protects against bore leakage due to sur face imperfections and makes the seal easier to install · The PTFE main lip allows the seal to function in poorly lubricated environments and in fluids that do not lubricate well · Individually designed multi-spiral pumping grooves are incorporated in the main lip to provide dynamic sealing and enhance fluid movement · Special barriers are integrated into the main lip to prevent leakage through the groov es when the seal is static · Seal design allows for radial and axial movement of the main lip that reduces the loading associated with bending · Because the rubber is bonded to the PTFE and the metal case during molding, there are no leak p aths · The elastomeric backing of the PTFE member assists in maintaining proper loading over the seal life and improves the radial resilience and shaft follow-ability of the PTFE sealing lip A special impregnated fabric dust lip (provided by Freudenberg Non-wovens) prevents dust and mud ingression even in the worst environments.