Busak+Shamban provide sealing solution for hydraulic cylinder controlling wind generator blade adjustment
Busak+Shamban developed new seals, wipers and bearings when commissioned to provide sealing for the hydraulic cylinder used to change the angle of the blade on the rotor blade of wind generators.
Wind power installed in Europe is saving over 50 million tonnes of CO2 a year and is on track by 2010 to deliver one third of the EU’s Kyoto commitment. The associated technology has inspired several innovative solutions in hydraulic sealing by developer and manufacturer, Busak+Shamban, in partnership with a leader in the engineering of wind power technology.
Technological improvements in wind turbine engineering continue at a pace and what was the largest wind power plant in the world is superseded by one, even larger! Masts are becoming higher and now exceed 120 metres, and at the same time, rotor diameter is increasing. Depending on the wind direction and wind force, the azimuth, or the alignment of the rotor and the pitch angle of the rotor blade, must be adjusted. The movement is carried out through the use of hydraulic cylinders within the safety-critical pitch system; an adjustment mechanism that employs quite advanced engineering technology.
Photograph of typical wind generation plant
With each rotor blade, there is a hydraulic cylinder to change the angle of the blade which rotates ten to twenty times a minute, relative to the wind force. Busak+Shamban was commissioned to provide sealing for this mechanism and, in response, developed new seals, wipers and bearings for the hydraulic drive piston rods and cylinders. A Turcon® Stepseal® 2K, manufactured from the high-performance seal material Turcon® T29 was used in tandem arrangement with Excluder® 5, from Turcon® T40 material, bearings produced from C320 material and piston seals produced in the Glyd Ring® Hz system and Turcon® T29 materials.
The sealing and bearing system is in constant use and permanently under pressure. At high wind speeds any failure of pitch adjustment could have serious consequences; highlighted in ‘Failure Mode and Effects Analysis’ (FMEA) testing recently carried out by a European wind power plant developer, together with the Allianz technology centre in Munich, Germany. The analysis, undertaken on a major installation, provided information relating to optimum operational performance values and safety, and included the Busak+Shamban sealing configuration as part of the study.