PTFE labyrinth seal with extremely long service life

Paul Boughton

As the link between the rotor and the generator, the main gear is the heart of every wind turbine.

Freudenberg Simrit's PTFE labyrinth seal Radiamatic RCD, which was specially developed for this application, is a highly efficient solution that offers the prospect of a service life lasting several decades. The outstanding advantages of this seal for gear and wind turbine manufacturers and wind farm operators include: a consistently reliable sealing function; a service life that lasts several decades; cost savings as a result of shaft surfaces and housings that are very inexpensive to manufacture.

The Radiamatic RCD is designed to seal splash lubrication in high-quality components in the field of power transmission engineering and has been used with great success in ship diesel engines, for example, since 2004. RCD stands for Reject, Collect, and Drain: the three key principles of function in what are known as liquid-collecting labyrinth seals.
The seal comprises two parts and features a rotating inner ring and a stationary outer ring. The inner ring is open and is kept in place on the shaft by springs. The outer ring sits securely in the housing bore.
The main components of the seal are made of PTFE, which means that they are chemically resistant to additive oils, ozone resistant, and slow to age˜all of which are relevant for wind turbine gears. This, in conjunction with the non-contact operation of this sealing solution in wind turbine gears, means that the service life of these seals is expected to last several decades.

Freudenberg Simrit does not use any dies in the manufacture of the Radiamatic RCD. This is a significant cost advantage for the manufacturers of gears and wind turbines and allows for rapid adaptation to individual sizes while keeping prototype delivery times to a minimum. When it comes to adapting to size, Freudenberg Simrit is willing to exchange 3D CAD data with the customer.
For more information, visit

Recent Issues