Wind turbines not only require extreme protection against weather and mechanical forces, but also solutions that are robust and offer long life cycles. After all, no one wants to provide maintenance for an offshore system twice a week.
Machines are only as good as their parts, and it’s often the case that the smallest components have the largest influence on the lifespan and reliability of an entire system.
Component design often overlooks the importance of well-engineered seals. Sealing solutions prevent media from escaping or entering, and play a critical role in the successful workings of the overall system. From a basic O-ring seal to more complex multi-part sealing systems, the simple act of “keeping something in or out” is a vital aspect in the correct function of wind turbines.
Whether onshore or offshore, wind turbines need to withstand large-scale temperature changes. As a result, sealing components need to be made with materials that are able to withstand these extreme fluctuations, especially extreme cold, without comprising shape, structure, or sealing ability. This makes the choice of material a critical component in the development of a proper sealing system.
Sealing elements made from polytetrafluoroethylene (PTFE) compounds are particularly suited for the requirements of wind power stations:
- Very good wear resistance due to the use of optimised PTFE components
- No restrictions regarding media or environmental influences
- The possibility to manufacture small volumes with custom-specific dimensions and designs
Products made from PTFE and PTFE compounds are used in virtually all fields of engineering; from the automotive industry, plant and mechanical engineering to medical technology. These compounds can be adapted individually to suit the specific application profile.
PTFE’s most important properties include:
- Virtually unlimited chemical resistance
- Expansive operating temperature range (-250°C to +250°C)
- No water absorption
- No cracking or ageing
- High levels of anti-adhesive properties
- Lowest friction
- Excellent di-electric properties
Geographic-specific conditions and the system’s surface environment can also impact seal performance and behaviour. Other factors that need to be considered include; mechanical loads, temperatures, greases and other media.
The accurate evaluation of all these factors can provide engineers the vital information to select the best solution for the type of application.
UK Seals supply a range of highly effective and easily maintained sealing solutions for wind turbines that can prolong service life.
The main brake assists the turbine in stopping at the critical rotor speed for maintenance. Seals found here are Scrapers, Wear Rings and Rod Seals. These seals can also found in the Yaw Brake which keeps the nacelle in a steady position towards the wind. The main brake, Yaw brake and rotor locking system all have critical safety related functions within the turbine. The sealing solutions inside must provide reliability of function whether it’s in the desert heat or the chill of the North Sea.
The pitch cylinder and actuators control the angle that the rotor blades face the wind. Seals are a vital part of the system withstanding millions of strokes. Piston seals, static seals, wear rings, scrapers and rod seals are all used in this application. They offer perfect leakage control and maximise the service life.
Rotary seals (radial oil seals) are vital to the effectiveness of the turbine. They are found in the main gear which converts the rotation of the blades into a speed suitable for the generator. They are also used to hold the main shaft in position and for the transmissions.
The transmission provides the link between the blades of the turbine and the generator. There are many different variations that offer high-efficiency and low maintenance. Rotary seals consist of a single lip bonded to a metal support with a garter spring.
Lip seals are typically retained in a housing bore by a rubber-to-metal, or a metal-to-metal press fit requiring considerable installation force. Press fits can let metal shavings enter a bore housing, leading to contaminated lube and premature bearing failure. Also, nicks, burrs, or scratches on a shaft surface can damage a seal lip and produce a leak. A mounting tool prevents damage, such as lip roll-over.
A variety of specialist materials are available to suit the most demanding of environments. UK Seals’ relationship with their reputable suppliers means that the company has some of the best engineers, designers, research & development and test laboratory facilities at their disposal.
UK Seals’ large diameter sealing products are specifically designed to meet the needs of Maintenance, Repair and Overhaul (MRO) customers. Our tried and tested extensive range also caters for heavy machinery Original Equipment Manufacturers (OEMs), without compromising on cost, delivery and specification.
For more information on sealing solutions for Wind Power, take a look at our Products section on our website, or contact our expert technical team. Call +44 (0)1388 722817 or email email@example.com.