Clifford Spring Co. developed an energy absorbing spring for the oil and gas industry that is non corrosive, chemical resistant, with high and low temperature resistance. The company selected a Vitrex Peek to develop the spring.

Victrex Peek (polyaryletherketone) polymers is said to be a good choice when replacing metal wind-turbine components. The high performance and light-weight material allows up to a 70% weight reduction. This can lower stress on the components and reduce energy needed to power the turbine. The tribological characteristics of this thermoplastic compared to metals also helps reduce downtime due to the inherent ability to perform with or without lubrication.

The polymers are useful in wind turbine applications such as bearing separators, connectors, braking systems, and pitches and yaw drive components. The material can be applied to wind equipment to create products that are more corrosion and high temperature resistant, light-weight, durable and stable. Most notably, wind turbine products benefit from PEEK’s strength and wear properties. Victrex polymers also prevent galvanic corrosion, and are an exceptional insulator for generators, motors or transformers. The polymers help extend equipment life, reduce product failures, improve thermal performance and material strength.

Victrex Corp.
Victrex.com

Windpower Engineering & Development

Seals, indicated in black, are used on a variety of bearings in a nacelle. Improving seal function improves the reliability and efficiency of the turbine. -Simrit

• Size – shaft, housing bore, and available seal width
• Temperatures – continuous and maximum
• Application parameters – equipment, sealing surface misalignment to housing bore, dynamic shaft run-out
• Media – type and level of lubricant
• Pressures – continuous and maximum
• Shaft surface speed – continuous and maximum. From these, select either lip seals or isolators.

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.

By comparison, isolators are easy to install. Isolator seals facilitate the installation and maintenance of sealing systems. They usually have O-rings on their inner and outer diameters to seal on the shaft and against the bore. To prevent damaging O-rings, the sealing surfaces of the shaft and bore must be cleaned prior to installation. O-rings are not dynamic sealing elements so they are not subject to wear. Once equipment is cleaned and inspected, an isolator can usually be installed by hand pressure alone.

Leak detectors (sensors) on some seals measure leakage. (Read more in 1:09 Sensors) Other sealing tasks in a nacelle include:

At the hub where blades pitch: These junctions must be weather tight yet allow rotation. Several designs in a range of materials are well suited for the application. For instance, a form-pressed continuous ring works well on the large dimensions. Its good performance is due in part to a rust-proof tension spring which pulls the seal against a rim. The seal comes in 200 to 1,700-mm diameters. Profile rings for large seal areas are batch vulcanized for advantages over glued rings.

Profile rings come in standard materials and others, and are said to ensure long working lives, low torques, high resistance, and ensure against press-out. They are well suited for sealing large-diameter bearings on pitch and yaw mechanisms. Main shafts: An on-site joined seal concept is said to replace a typical turbine main-shaft seal in less than 30 min and without major disassembly. On-site joined seals claim to offer the same integrity, life, and performance as the seal fitted during manufacture by an OEM.

Slewing bearings: One company has added two more formulations to its line of nitrile butadiene rubber (NBR) sealing materials for grease and ozone resistance, low-compression set, and low-temperature capability. Both materials were developed for long-term reliability and superior resistance to environmental and chemical concerns.

The company says the recent NBR materials offers excellent cold flexibility, good compression set, and demonstrates superior aging in several greases, including Kluber, Fuchs, and Mobil. Recent premium materials are said to provide superior compression set and are optimized for use in Shell Rhodina BBZ greases.

Offshore wind foundations: These provide one of the more unusual sealing tasks for wind power. These are built with structures such as monopiles and tripods. A monopile (single leg) provides an example. After the pile is driven into the sea bed, its top extends up to about 16-ft., but below the water surface. A transition piece, about 80-ft high, is lowered over the top of the pile and will clear the water by some 40 ft. An inflatable grout seal, much like an inner tube, is then fitted in the space between the pile and transition piece. This seal inflates with a few psi to close the substantial gap between monopole and extension. Grout is then pumped into the gap above the grout seal to produce a strong joint. A floating crane then installs the turbine.

Windpower Engineering & Development

Seals, indicated in black, are used on a variety of bearings in a nacelle. Improving seal function improves the reliability and efficiency of the turbine.

In July 2008, the Energy Efficiency and Renewable Energy Department of the U.S. Department of Energy published a document 20% Wind Energy by 2030 that included wind-energy volume projections. The projections were based on many factors and assumptions, including justification of capital, improvement of wind-turbine efficiencies, lower annual maintenance costs, and reliable component life.

Increasing component reliability to achieve 20% wind energy will require advancements in component design, materials, and testing methods to validate wind-turbine components in the harshest environments. No component should be overlooked in the quest to increase energy captured by wind turbines. For example, if the seal for a blade pitch bearing—which many consider a commodity—is unreliable, designed improperly, or made with poor material, it will leak grease and eventually prevent the blades from pitching. The whole turbine will under-perform. Hence, small components can have a big impact when not properly designed or tested.

Slewing-bearing seals should also keep grease in and detrimental environmental elements (dirt, salt, water, sand) out of the bearing’s working elements. This sounds simple, but many factors contribute to the proper function and reliability of the seal. As OEMs build larger wind turbines and expand into new regions of the world, some factors will change to influence life expectancy and reliability of slewing-bearing seals. Thus, seal suppliers require close cooperation with those bearing companies, grease suppliers, and M&O groups to ensure the proper evaluation and evolution of these components.

Realizing that a single component cannot drive the 20% energy goal alone, it is vital to recognize and appreciate how each turbine

The seal cross section illustrates the complexity to which Simrit can design. Bearings in each turbine model can differ from each other and would require different seal cross sections. Seals for any diameter bearing are extruded, cut to length, and bonded.

component plays an important role in making the turbine industry successful. As a result, many companies continue to invest in new materials and designs. Two recent material examples are Ventoguard 453 and 454, formulated for ozone resistance and reduced compression set, as well as newly improved seal geometries that keep grease where it belongs, increases seal life, and improves turbine service.

In addition to design and material innovations, new technologies are being developed to address industry-related challenges. One example is a way to reduce seal friction that can influence the motor size needed to pitch a turbine blade. Larger wind turbines require large slewing bearings (over a meter in diameter) hence large diameter seals. Reducing the friction between bearing and seal helps decrease pitch-motor size. Smaller motors mean a lower-cost machine to rotate the blade and—to some extent— less tower weight.

Growing the wind industry market to 20% in North America will require continuous collaboration and experimentation to increase the reliability of wind-turbine components. Improved material properties and seal geometry of slewing-bearing seals is just one way to increase turbine life and reduce overall project costs. WPE

By: Steve Koch, Special Sealing Products Division of Simrit, Freudenberg-NOK Sealing Technologies

Windpower Engineering & Development

Extensive testing showed Turcon M12 resistant to most all media, including a broad range of lubricants, and has outstanding wear resistance and friction characteristics.

Turcon M12, a PTFE-based material launched in 2011 by Trelleborg Sealing Solutions, has received a 2011 Innovation Award from Flow Control Magazine. According to the company, the PTFE-based sealing material has unrivaled performance in key hydraulic sealing characteristics such as friction, wear, and high-pressure operation. Testing shows Turcon M12 resistant to most media, including a broad range of lubricants, and has outstanding wear resistance and friction characteristics. The cost-effective material also provides an extended seal life, as well as a wide operating window in temperature, pressure, and velocity.

 “Turcon M12 has exceeded even our expectations,” said Trelleborg Sealing Solutions Product Manager Nancy Getz. “On most every parameter it is better than, sometimes significantly, than previously recommended compounds or was at least equal to them.”

Trelleborg Sealing Solutions
www.trelleborg.com

Windpower Engineering & Development

A cross-sectional size of 25 mm x 32 mm so the UltraWind P1 Seal is intended to easily retrofit standard elastomer seals.

The Timken UltraWind P1 Seal is a significant wind-turbine bearing seal with a polyurethane design that provides increased resistance to abrasion for longer wind-turbine service life and more reliable performance than most other commonly used sealing materials. “Seals have an integral role in maximizing wind-turbine uptime and productivity because they prevent lubrication leakage and bearing contamination,” said Hans Landin, director of Process Industries original equipment and wind energy at Timken. “However, over time the cumulative impact of abrasive forces caused by varying loads and speeds, as well as extreme temperature fluctuations, rain, snow, debris, and lubrication challenges, can significantly reduce seal performance in wind-turbines. The new UltraWind P1 Seal addresses the problem with the latest polyurethane technology.”

In addition to its durable polyurethane base, the Timken UltraWind P1 Seal contains a variety of other features, including:

• A flexible sealing lip that handles misalignment or run-out in the application of the bearing. The lip’s special profile also helps minimize heat generation and cone wear while helping to accommodate bearing deflections.
• A corrosion-resistant, stainless steel garter spring that helps prevent rust.
• A machined design for a broader, more diverse range of applications, plus ease of installation via stress minimization. This design also allows for multiple positions at the cone lip OD contact; and

The Timken Company
www.timken.com

Windpower Engineering & Development

The company even held a party in anticipation of this momentous occasion. What started out as a simple gathering soon became a source of company pride and success. Over 400 employees, partners, clients, family members and special guests from around the world gathered to commemorate this achievement.

“It took Magni 37 years to achieve this milestone,” says The Magni Group’s Founder-Chairman, Dave Berry. “Now, with Magni’s rapid growth, the company is on course to produce one million gallons every year.”

The event featured lavish food, raffle prizes, and a number of surprises, including the high-energy Eastern Michigan University cheerleaders who burst through Magni Industries’ closed side doors to get the party started. On-stage, the Berry family clapped along with the crowd as the choreographed dance squad performed to the songs, “Celebration” and “The Final Countdown.”

As everyone anxiously awaited the 10 millionth gallon of coating product coming off the on-site production line, they counted down in true Times Square fashion. Three, two, one…and confetti filled the tent, after everyone squeezed off rounds from their six-round, celebratory popper pistols.

To put the icing on the cake, Detroit City Councilwoman Saunteel Jenkins, Oakland County Deputy Executive Phil Bertolini, and 13th District Michigan Congressman Hansen Clarke stopped by to pay tribute to Magni’s accomplishment. Speaking of cake, everyone also enjoyed a piece of the special four-tier, building-shaped dessert.

Once the confetti settled, Magni Group’s President Tim Berry unveiled another off-the-agenda surprise when he presented Dave Berry, company owner, (and dad), with a giant 3.5’x1’, accordion-folded birthday card, signed by every Magni employee from the 20 Magni facilities worldwide. It took five months for the card to travel across six continents to collect 380 signatures. The card was printed with “Happy Birthday” in seven languages—English, French, German, Japanese, Korean, Portuguese, and Chinese.

Other surprises included Ted Berry, Magni’s Executive VP and singer-guitarist of Magni’s house band, giving his fellow musicians new logo-imprinted stools, stickers, and coasters.

“Only Magni people and our cherished clients can bring such profound energies to an event and make it unforgettable”, says Jen Hall, Magni Marketing. “It’s just magical to feel the enthusiastic spirit only hard-working, good-hearted partiers can bring.  And it’s a relief to finally have all the special secrets revealed!”

With all of the excitement, believe it or not, no one even noticed the rain.

The Magni Group Inc. www.themagnigroup.com

Windpower Engineering & Development

“The windpower industry is growing and evolving at a rapid pace,” says Reddy Tudi, sales director, renewable energy, Simrit. “To meet the needs of this developing industry, Simrit engineers are continually driving the development of materials and seals that will extend the performance of windpower applications.”

Ventoguard 453 and Ventoguard 454 are the next-generation of the company’s line of NBR materials. Primarily used in slewing bearing profile seals in wind turbines, both materials were developed for long-term reliability and superior resistance to environmental and chemical concerns.

Additionally, each material was designed to address a specific windpower-related challenge with the ultimate goal of helping prolong the maintenance cycle of the sealing application. The company says Ventoguard 453 is a premium material that offers excellent cold flexibility, very good compression set and demonstrates superior aging in several greases, including Kluber, Fuchs and Mobil. Simrit’s Ventoguard 454, also a new premium material, provides superior compression set and is optimized for use in Shell Rhodina BBZ greases.

Simrit www.simrit.com

Windpower Engineering & Development

Application data required to select a seal includes:

•Size – shaft, housing bore, available seal width

•Temperature – continuous and maximum

•Application parameters – equipment, sealing surface    misalignment to housing bore, dynamic shaft run-out

•Media – type and level of lubricant

•Pressure – continuous and maximum

•Shaft surface speed – continuous and maximum.

From these, select either lip seals or isolators.

Lip seals are typically retained in a housing bore by a rubber-to-metal or 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.

By comparison, isolators are easy to install. Isolator seals facilitate the installation and maintenance of sealing systems. They usually have O-rings on their inner and outer diameters to seal on the shaft and against the bore respectively. To prevent damage to O-rings, the sealing surfaces of the shaft and bore must be cleaned prior to installation. O-rings are not dynamic sealing elements so they are not subject to wear. Once the equipment is cleaned and inspected, the isolator can usually be installed by hand pressure alone.

There are many other sealing tasks in a nacelle. Hydraulic equipment, of course, needs them. Leak detectors (sensors) on some seals measure leakage. Onboard electronics then provide some analysis and can send results to a computer or telephone. This allows remotely monitoring a seal and scheduling an exchange when necessary in a normal maintenance interval.

German DIN 3760 standards describe function and lifespan for such seals. The sensor-seal combination is available in many different dimensions. The seals protect motors and machines in original equipment and provide options for maintenance personnel. Designs in special materials are available especially for wind turbines.

Where blades meet hubs also call for a seal. These junctions must all be weather tight yet allow rotation. Several designs in a range of materials are well suited for these applications. For instance, a form-pressed continuous ring also works well on the large dimensions encountered in wind turbines. Its good performance is due in part to a rust-proof tension spring which presses permanently against the seal rim. The seal comes in 200 to 1,700-mm diameters.

Profile rings for large seal areas are batch vulcanized for advantages over glued rings. Profile rings come in standard materials and others. The rings are said to ensure long working lives, low torques, high resistance, and security against press out. They are well suited for sealing pivoting large diameter bearings found on pitch and yaw mechanisms.

One of the more unusual sealing tasks on turbines deals with offshore foundations. Wind-power stations there are built using structures such as monopiles and tripods. How the turbine is installed depends on soil properties, water depth, and contractor experience. A monopile (single leg) provides an application example. After the pile is driven into the sea bed, its top will extend up to about 16-ft below the water surface. A transition piece, about 80-ft high, is lowered over the top of the pile and will clear the water by some 40 ft. The space between the pile and transition piece is sealed by an inflatable grout seal, much like an inner tube. This seal inflates with a few psi to close the substantial gap between monopole and extension. Grout is then pumped into the gap above the grout seal to produce a strong joint. A floating crane then installs the tower to the extension and the turbine.

Windpower Engineering & Development

Trelleborg Sealing Solutions
www.tss.trelleborg.com/us

Windpower Engineering & Development

Magni Industries’ Electron Scanning Microscope, one of the company's four ES Microscopes, is used here by Kevin Ruddy and Jeanette Clinton, Analytical Chemists. Research teams use this ESM for development and analysis of Magni coatings.

Protective coating manufacturer The Magni Group Inc. will produce its 10-millionth gallon of coating this month. Dave Berry, chairman of the company started a metal finishing company, Depor Industries, near Detroit in 1974. Parent company, The Magni Group Inc., came about after an automotive chemical coating supplier partner moved to license with another local metal finisher; Dave then, decided to develop his own coatings. Magni Industries-Detroit was established in 1978 and is known for its R&D laboratory and manufacturing plant. During the 1980s, the company grew with the automotive industry by offering corrosion-resistant coatings that provide metal components with a longer service life and increased durability.

Now, in addition to its automotive customers, the company serves the agricultural, construction, heavy truck, marine, military and off-highway markets worldwide with an excess of 100 different coating systems. The company’s engineered coatings are custom-designed to meet the performance criteria of customers’ fasteners, fuel and brake specifications and a range of other metal products by resisting the corrosive effects of heat, humidity, etc.

Berry family, owners and founders of the Magni Group, seated together.

Magni has 20 company-owned operations in North America, Japan, China, India, Europe, and Brazil. The company will open new technology centers in both countries by 2012. Magni will celebrate its10-millionth-gallon achievement with more than 400 global leaders and engineers at their coating manufacturing facility in Detroit, Michigan, on Friday, May 6th. Government Officials, Detroit City Councilwoman Jenkins, Oakland County Deputy Executive Bertolini and Michigan Congressman Hansen Clarke, will be presenting awards to the Berry family on-stage. The private event will also host plant tours, display a historical museum and the official 10,000,000th paint can from coating production will be sealed during the ceremony on-stage.

The Magni Group www.themagnigroup.com

Windpower Engineering & Development