German company Liebherr is offering their hydrau-lic cylinder for hydraulic pitch adjustment in wind turbines to the American market. The company offerso both electromechanical pitch adjustment with gearboxes as well as hydraulic pitch adjustment with the corresponding blade bearings as a full system. Cylinders are supplied in accordance with a customer’s particular requirements, in-cluding piston rod heads and integrated stroke measuring systems.
The cylinder fits perfectly to a large diameter bearing of 2,100 mm in diame-ter, typical for a 2-MW wind turbine. It has a piston diameter of 125 mm and stroke length of 780 mm, weighing 172 kg including piston rod head.
The company says their hydraulic cylinders are significant because of careful selection of material, high standard of technical precision of the components, an exactly matched sealing system, and particularly low wear in operation. The manufacturing range for hydraulic cylinders extends to up to 5,000 mm stroke length and 500 mm piston diameter.
Liebherr, though a sys-tem supplier, is able to offer bearings and drive systems, as well as hydraulic cylinders and control technology, from its own development and production resources. In the sector of large bearings for blade and yaw adjustment in wind power systems, Liebherr manufactures four-point bearings in single-row and two-row versions. All these bearings are characterized by top quality and long service life. The range available among drive systems includes multi-stage coaxial planetary gearboxes, which can be flexibly adapted to every customer’s particular requirements. Liebherr drive systems are particularly famous for their reliability, the compact structural design, and the ideal power-to-weight ratio. Electric motors to supplement the drives likewise come from Liebherr’s own development and manufacturing facilities and resources.
There are essentially no limits on the structural size of the drive elements. The product range includes components for supplying wind turbines from 750 kW through to large tur-bines with rated capacities of 7.5 MW, for operation on land as well as for offshore systems.
Filed Under: Hydraulics, Pitch & yaw