Oil seals have come a long way since the first Simmerring in 1950.

From the Simmering® brand of the German invention to the Italian Patent CORTECO® the Oil Seal is in constant evolution to meet the increasing demands in various applications. From the first model produced from leather waste of the Freudenberg tannery in the fifties, oil seal materials moved on to synthetic rubber (elastomer).

In the eighties, the Combi oil seal was developed, suitable for application on axles of agricultural and construction machinery. The wear-resistant polyurethane wiper assures protection of the seal lip from water, dust, and mud.

A special version of the combi seal is the cassette seal. Here, the seal rotates on its sleeve but not on the shaft, which avoids expensive maintenance. The high rotation speed of the modern engines and the increase of the temperatures of the contact surface between seal and shaft made it necessary to develop new materials and solutions. The best solution compared to the lip seal designed in FKM (Fluoro elastomer) is the utilization of PTFE (Polytetrafluorethylene).

The PTFE material can withstand temperatures higher than those of the standard oil seal. Moreover, no elastomer oil seal can work through extended periods without lubrication, while the PTFE seal can work also in conditions of insufficient oil inflow. With PTFE, because of the wide contact area (not a corner seal), the depth of the wear groove in the shaft is reduced and generates less radial force compared to a standard oil seal, decreasing the wear on the shaft.

Influences on Seal Performance

Seal performance is determined by a number of influences:

• Working conditions (temperature, pressure, shaft rotation speed, friction, inside/outside contamination, etc...)
• Shaft characteristics (surface roughness, eccentricity, material, hardness, etc…)
• Housing characteristics (machining level, material, shape, rigidity, dimension, etc…)
• Assembly process
• Elastomer types and related properties ( chemical and physical characteristics )
• Ambient corrosion ( water, powder, mud, etc…)
• Fluid (viscosity, pressure, chemical composition, contamination, etc…)
• Oil seal design ( radial force, lip design, lip execution, spring, etc...)

About Corteco

CORTECO is the service specialist for the Independent Automotive Aftermarket (IAM) of the Freudenberg Group. The company offers spare parts for Sealing and Vibration Control as well as service parts like cabin air filters and brake hoses. The Freudenberg Group employs more than 33,000 people in 55 countries and is a leading Original Equipment Manufacturer (OEM) in the respective product groups. The products therefore have already been well established in the first equipment market worldwide and enable garages to profit from OE quality spare parts from CORTECO. More than 18,000 references underline CORTECO's position as one of the leading suppliers in the IAM. The company distributes its spare parts and kits from 8 locations in Europe and 5 more locations in other parts of the world.

As a specialist for the IAM, CORTECO is also responsible for the distribution of micronAir cabin air filters of Freudenberg in the German IAM since January 2007, and from 2008 on all over Europe. The proven micronAir filters are designed and manufactured by Freudenberg and supplied to OEMs worldwide, making Freudenberg the market leader in Original Equipment cabin air filters: more than half of all new vehicles are equipped with a micronAir cabin air filter.

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