Freudenberg Sealing Technologies
First-Hand News?

Obtain news and background information about sealing technology, get in touch with innovative products – subscribe to the free e-mail newsletter.

New Large Seal from Freudenberg for Grease-Lubricated Main Bearings in Wind Turbines

Weinheim (Germany), September 25, 2018. A component’s reliability and service life are top priorities for wind turbine manufacturers. This is especially true for main shaft seals, which are exposed to powerful forces. In addition, larger shaft diameters have prompted adoption of new, more stringent operating requirements. Freudenberg Sealing Technologies has succeeded in developing a new seal that reliably prevents leaks from the grease-lubricated main bearings used in conjunction with these shafts while tolerating strong shaft runout. The company is exhibiting this bearing, along with other innovative wind energy solutions, at booth 531 in hall B6 during the WindEnergy 2018 trade fair in Hamburg (Germany) from September 25-28.

Manufacturers continue to increase the size of wind turbines in an effort to generate an ever-increasing supply of clean energy. Larger turbines result in lower material and construction costs than installing multiple, smaller turbines. Rotors with a diameter of 180 meters are no longer rare. But systems of this size produce powerful forces during operation that impact main shaft roller bearings and seals, thus requiring new seal designs that have been adapted to these conditions. Freudenberg Sealing Technologies has now succeeded in developing a seal for grease-lubricated bearings for large shaft diameters. The product can be used for radial internal and external sealing and can even tolerate strong shaft runout.

FST Seventomatic

Traditional shaft seals that produce pre-stressing forces on the seal lip by using a worm spring reach the limits of capabilities when large diameters become a factor in their design. In addition, solutions providing radial external sealing are difficult or even impossible to execute with this design. Freudenberg Sealing Technologies’ new shaft seal “Seventomatic” is intended for shaft diameters starting at 1.5 meters. It uses a meander spring to build up the needed pre-stressing forces. The product gets its name from the figure “7” – a long sealing leg is linked with the stationary portion of the seal using a flexible joint.

The Seventomatic seal produces consistent linear forces and is less susceptible to shaft runout than other shaft solutions. In its standard size, the shaft seal tolerates a deflection of ±4 mm without a decline in its performance. As a result, it handles the shaft’s manufacturing tolerances extremely well. It is made from hydrogenated nitrile butadiene rubber, a material in the Ventoguard family of wind energy solutions. The basic form of the Seventomatic is based on Freudenberg Sealing Technologies’ tried-and-tested seals for tunnel boring machines. The goal was to combine the special design of a seal for tunnel boring machines with the advantages of a classic radial shaft seal ring for the rotor’s main shaft.

Comprehensive simulations made it possible to ensure a robust design in advance. Using the data sets they acquired, engineers created a mathematical model so they could predict the behavior of the seal with regard to linear force and the maximum potential results of shaft runout and eccentricity. These robust design simulations covered the requirements so completely and precisely that it was hardly necessary to make adjustments to the physical prototype. When endurance tests with approximately 15 million load changes were run on samples, the engineers found neither identifiable damage nor limits on the Seventomatic’s capabilities. Other testing dealt with temperature changes between -30 and +100°C as well as stability during vibrations of 8 Hz with an amplitude of ±3 mm at 110°C. In addition, there was an investigation of the linear forces of mounted seals after 240 days of storage at room temperature and at 100°C.

The results showed that the new Seventomatic seal reliably retains the grease used in turbine roller bearings and is not susceptible to static and dynamic eccentricity while offering a constant linear force. The new Freudenberg Sealing Technologies development supports the trend to ever-larger wind turbines for the efficient and reliable production of clean energy.

Ulrike Reich

Ulrike Reich

Head of Media Relations & Internal Communications

Telephone: + 49 (0) 6201 960 5713

ulrike.reich@fst.com
Cutout of a keyboard with enter key on which an envelope is shown

Press Release Subscription Service

You can subscribe to the Freudenberg Sealing Technologies news alert service, bringing you the news as soon as they are published. You can always unsubscribe from this service.

Subscribe now!

Further articles with these taggings

Making Carbon

09.08.2022

The world cannot do without technical plastics. But if the extraction of fossil materials comes to an end, new sources of carbon will be needed.

Read more

Sustainability

Fresh From the Lab

02.08.2022

“Just a steak from the 3D printer with hightech vegetables.” That’s what your restaurant order could sound like even today, thanks to new food concepts created to feed a growing global population.

Read more

Sustainability

Taking Care – Together

26.07.2022

Companies around the world want to operate more sustainably. With the “We All Take Care!” program, FST pays tribute to sites with the best initiatives for improving their sustainability.

Read more

Sustainability

The Glue of Civilization

19.07.2022

The production of cement releases huge quantities of CO₂. But concrete is affordable and hard to replace. Why exactly is that?

Read more

Sustainability

Troubled Waters

12.07.2022

Weather extremes are becoming more common due to climate change. But how do cities cope with times of extreme drought or heavy rain? There are many approaches, and not all of them are sustainable.

Read more

Sustainability

“Dance – Or the Lights Will Go Out!”

05.07.2022

Coldplay took two years to plan a sustainable world tour. The result: the “Music of Spheres” tour of 2022. The band is traveling halfway around the world on the tour – with half of the CO₂ emissions.

Read more

Sustainability

A Green Oasis on the Factory Grounds

30.06.2022

You don't necessarily expect to grow bananas, spinach and tomatoes on a factory site. A team from the Freudenberg site in Chennai, India, has done just that and is meeting with great approval.

Read more

Sustainability

Sealing Expertise for Green Hydrogen

29.06.2022

Freudenberg Sealing Technologies produces electrolyzer sealing solutions by applying fuel cell knowledge

Read more

Energy Generation Special Seals Sustainability

Every Color Is Green

21.06.2022

The fashion industry has a sustainability problem. The proportion of emissions and synthetics is increasing. But there is another way - with bio-based plastics.

Read more

Sustainability
Newsletter

First Hand News

Best of all, keep up with the latest developments
with the Freudenberg Sealing Technologies newsletter.

Subscribe now!