Gear box manufacturer Flender AG of Germany is seeking partners to develop a drive train concept for 5 MW turbines that it presented earlier this year at the Hannover Trade Fair. As wind turbines have grown, technology developers have begun to concentrate more upon how to reduce weight-thus reducing cost and increasing profits-of megawatt size machines. Flender's new lightweight drive concept promises considerable weight reduction, the company says. The concept builds on tight, intersection-less interlocking of electronics, electricity and mechanics, according to Flender's Alfred Schoo. The rotor hub and blades are connected to the nacelle bedplate by a large bearing only-doing away with the heavy rotor shaft. "In this way, the whole power of the wind is channelled directly into the tower," says Schoo, adding that the torque of the rotor is thus transmitted to the main stage of the driving unit. "The double-stage planetary drive increases the speed and transmits the torque to the generator. In this way, driving unit, generator and machine carrier form a compact unit."
Flender does not wish to produce its own 5 MW wind turbine incorporating the concept, as has been rumoured, but hopes to co-operate with a turbine manufacturer and a wind power station operator to test the prototype machines. "We have presented the concept to all our customers and have held exploratory talks with a handful of companies," says Flender's Stefan Spruck.
Flender, based in Bocholt, is moving its manufacturing operations to a factory at Friedrichsfeld, also in North Rhine Westphalia, where the new drive will be made. Gear boxes will not only be assembled at the new facility, but also checked for quality, certified and presented for customer acceptance. Existing workshops are being revamped and operations are due to begin at Friedrichsfeld in November or December.