Freudenberg's Accumulators help Balance Demand for More Reliable Wind Power

Freudenberg has worked in close collaboration with wind turbine manufacturers to address conditions such as temperature, friction, fluid resistance and wear with a portfolio of accumulators and sealing products that extend the durability of the drive systems inside these giant power generators.

PLYMOUTH, Mich., June 28, 2016 /PRNewswire/ -- A recent American Wind Energy Association (AWEA) 2016 WINDPOWER conference identified wind as the fastest growing new source of electricity in America. What this means for wind turbine manufacturers is clear: increasing demands for this renewable power are driving turbine construction in locations where environmental factors can make maintenance expensive and challenging. Wind systems must, accordingly, be more reliable than ever.

Freudenberg has worked in close collaboration with wind turbine manufacturers to address conditions such as temperature, friction, fluid resistance and wear with a portfolio of accumulators and sealing products that extend the durability of the drive systems inside these giant power generators.

The materials and products Freudenberg offers wind customers to seal and protect these systems from environmental challenges have been uniquely engineered to resist abrasion, increase system longevity and help keep maintenance to a minimum.

"One of the predominant trends to emerge in the industry is an increase in the size of the wind turbines. This trend puts pressure on engineers to not only cope with harsh environmental conditions and structural requirements but to also balance high expectations regarding functionality and lifecycles," said Michael Littig, Segment Director for Energy with the company. "Freudenberg has focused its expertise on meeting these expectations and requirements."

Freudenberg offers wind turbine manufacturers a variety of pressure accumulators including diaphragm, piston and bladder accumulators to help keep these energy systems operating efficiently and minimize unplanned maintenance. The company's piston accumulators incorporate a unique seal design that offers customers nearly maintenance-free operations by reducing pre-charge losses. Those seals ensure lower leakage than competing seals and the pre-charge lasts significantly longer in systems equipped with these components.

Accumulators from Freudenberg come in a variety of sizes from small diaphragm accumulators to very large bladder and piston accumulators. They are used in the hydraulic pitch control unit, the hydraulic unit for brakes and in the pitch itself. They can handle pressure of up to 350 Bar or 5,000 psi and are also certified to global standards in the Americas, Europe and China.

In fact, the durability of sealing rings in hydraulic assemblies and components is crucial to the lifespan of the entire wind power system. Standard systems in hydraulic piston accumulators mostly work with two seals (back to back), one for oil and another for gas. If there is no pressure discharge, the smallest leak leads to a buildup of pressure between the seals and the destruction of the sealing system.

By contrast, Freudenberg uses a single seal, developed in-house, that consists of a polyurethane seal ring and an elastomer pressure ring. The polyurethane material is less susceptible to damage and more robust than PTFE during installation. Its high dimensional stability and extraordinary wear resistance are decisive for reliable sealing and a long service life. This makes Freudenberg's sealing technology especially attractive for use as a piston seal in the piston accumulators of wind turbine systems.

Freudenberg sealing technologies experts also offer an advantage in that the company's in house sealing solutions afford long service life, low hysteresis, compact design and a wide range of materials, seal types and configurations. The company uses its world-leading material expertise to work with customers both off site and in the field to help maximize wind system performance.

The company also offers customized solutions to wind turbine manufacturers which can be quickly produced as prototypes. From material development, mixing and testing to proposal drawing, in-depth failure analysis and on-site support, the Freudenberg sealing technologies experts can meet the most challenging demands of the wind power industry.

About Freudenberg-NOK Sealing Technologies
Freudenberg-NOK Sealing Technologies runs the business operations of Freudenberg Sealing Technologies (FST) in the Americas. Being part of the global Freudenberg Group, the company is a leading producer of advanced sealing technologies for a variety of markets including: aerospace; agriculture; appliance; automotive; construction; diesel engine; energy; food and beverage; heavy industry; and pharmaceutical. Freudenberg-NOK Sealing Technologies is a joint venture between Freudenberg and NOK Corp. in Japan, is headquartered in Plymouth, Mich. and operates more than 20 facilities across the Americas. For additional information, please visit

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