Page 17 - North American Clean Energy January February 2018 Issue

and gear parts. e WC/C ductile carbide carbon coating has a high load-bearing capacity, even when used with insu cient lubrication or dry contact. Due to its low-friction coe cient, the coating can drastically reduce fretting corrosion and pitting. By forming an e ective barrier between metal-on-metal contacts, it reduces metal structural damages such as white etch cracks and fatigue failure.
Alternatives to PVD coatings include black oxide, which is produced by a chemical reaction between the iron
on the surface of a ferrous metal, and oxidizing salts. After a post-treatment with oil, the surface provides protection against corrosion, improved lubricity, and prevents galling during metal-to-metal interactions. However, black oxide is not very durable; it can be worn away quickly in repetitive, high load applications.
Nitriding
ere are limitations to the size of products that can be coated with PVD, such as
the ring gears (in newer wind turbines) that can measure up to 2-3 meters in diameter. For these large gears, a nitriding process can be used. Nitriding is a heat treating process that di uses nitrogen deep into the surface of a metal to create
a case-hardened surface. Because it is not a coating, it does not a ect the overall dimensions of the component. Although traditional gas nitriding costs less, plasma nitriding has the advantage of making the treatment more precise, by minimizing warping and distortion, while achieving a higher load-bearing capacity.
In an FZG pitting test, one plasma nitriding process exhibited ve times less roundness deviation, and seven times better planarity than gas nitriding on
a 2-meter diameter ring gear. Another potential application for plasma nitriding is for treating the surfaces of large bearing cages used with wind turbine bearings. is increases the sliding wear resistance against the rollers, and can be used on components up to 3 meters in diameter, 10 meters in length, and weighing up
to 40 tons. Compared to gas nitriding,
the tolerances for roundness, planarity and parallelism can be adhered to much better, even with such large parts as the ring gears – vital for the service life of a system in which enormous forces are at work simply because of its size.
Dr. Rovere is the Director of Precision Components for North America for Oerlikon Belzers Coating USA. e company develops high performance PVD & PACVD coating solutions and surface technologies to improve the performance and durability of precision components and tools for the metal and plastics processing industries.
|
www.oerlikon.com/balzers
Oerlikon Balzers
Easy-to-use PPE
e Ignite Proton Wind from the Ignite Series of harnesses, which is certi ed according to ANSI Z359.11.2014, sets new standards with its many clever details in terms of ergonomics and design. Pre-shaped shoulder and leg pads and high-quality hip padding are ergonomically adjusted to the shape of the human anatomy. Not only does this prevent pressure points during wear, but it also relieves the spine because loads are distributed evenly. Another detailed solution is – as for all models in the Ignite Series – a new adjuster. is adjuster stops the straps from unwanted loosening when users are on the move for a long time. is means users no longer have to deal constantly with the problem of having to keep tightening the harness. SKYLOTEC | www.skylotec.com
ADVANCED BOLTING TECHNOLOGY
Light – Unsurpassed power-to-weight ratio Accurate – Designed to provide a high degree of accuracy (+/-2.8%) and repeatability (+/- 2%) Fast – Decreased tightening times by up to 300% Quiet – Operates at 75 db reducing noise level
With torque ranges up to 15,000 Nm, the E-RAD BLU uses a patented gearbox design and the precision of an electric AC Servo motor. These tools deliver smooth continuous torque and are capable of torque and angle sequence. They also feature enhanced traceability with data collection.
1.800.983.0044
WWW.RADTORQUE.COM E-RAD BLU
North American Clean Energy
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