Federal-Mogul Corporation (USA), in collaboration with Timken, has developed a non-contact 2-piece labyrinth seal, simultaneously addressing several operating limitations and inefficiencies of traditional contact lip seal designs. It is now being offered as an option on Timken's AP-2 freight rail wheel bearings.

In service, labyrinth seals are often preferred for many applications because they reduce parasitic drag caused by the felt, elastomer, or other material lips which are the basic design and construction of traditional contact seals. However, rail applications are so demanding that non-contact labyrinth seals had never moved beyond the laboratory.

Named EcoTurn, the F-M/Timken non-contact labyrinth seal not only eliminates the drag, but also the torque, excess heat generation, and in-service wear concerns of traditional lip seals.

Basic construction of the EcoTurn is straightforward. The rotating elastomer sealing element is molded onto a stamped metal carrier within a stationary outer metal shield. The design of the labyrinth path between the two is unique, and critical to its performance. That labyrinth keeps lubricant from weeping out of the bearing, while keeping out dirt, debris, and other elements. In addition, the non-contact seal does not generate or transfer heat, so the bearings themselves operate at a lower and more consistent temperature, which extends service life.

Timken said EcoTurn seals reduce each AP-2 bearing's operating torque by approximately 20 inch-pounds over their nearest competitor. That torque reduction has significant real-world implications in terms of lowering locomotive fuel consumption and the resulting emissions.

For example, the fuel needed to pull a 100 car train 100,000 miles is reduced by approximately 13,500 gallons. Nitrogen oxide and carbon monoxide emissions are reduced by approximately four tons, equivalent to 240 passenger cars.

An animation of the EcoTurn seal is here :

F-M / Timken Eco Turn seal cutaway animation
Gerard Chochoy, Federal-Mogul's senior VP for Powertrain Sealing and Bearings, said: "The EcoTurn seal has the potential to save millions of dollars in fuel consumption and maintenance costs, as well as dramatically reduce emissions released into the atmosphere. The non-contact seal eliminates seal-generated torque and temperature while maintaining seal integrity. As a result, it not only saves fuel, but requires less maintenance."

Doug Smith, Timken senior VP of Technology, said: "We set out to develop a seal that would outperform the lowest torque seal produced by Timken and our competitors. Our goal was to develop a seal that would significantly lower customers' fuel consumption. The result is the EcoTurn seal."

R&D Magazine awarded EcoTurn with an R&D 100 Award in Mechanical/Devices 5251R9N7 for being one of the top 100 product innovations introduced that year.