New drive concept for wind energy

The global market for wind turbines is growing continuously – with increasing demands on turbine performance and dimensions, both onshore and offshore. Against the backdrop of public and political debates about the future of energy supply, manufacturers are working intensively to increase the efficiency of their systems and further reduce the cost of wind power. A significant advancement is marked by the new Revo drive concept, which the German drive specialist Flender is presenting today under its Winergy wind energy brand. For the first time, a turbine drive achieves a torque density of 300 newton meters per kilogram – a technological milestone.

"With Revo, we are redefining the standards in wind power technology," says Andreas Evertz, CEO of the Flender Group. "The increased torque density raises efficiency while simultaneously reducing material usage – a crucial step towards even greater competitiveness and sustainability for the industry."

Greater efficiency through higher torque density

Revo is a validated design concept for new turbine generations and offers a torque density of 300 Nm/kg. This enables significantly more compact drive systems: For the same power output, the outer diameter can be reduced by up to 25 percent. Andreas Klein, Vice President Drive Systems and Gear Engineering for Flender's wind business, explains: "Torque density – also known simply as power density – describes how much torque a drive can transmit per kilogram of material – a key metric for the investment costs of a wind farm."

The compact gearbox design addresses several key challenges in the development of new turbines and offers far-reaching advantages: It reduces transport costs and enables road transport, even for current and future power classes beyond 8 megawatts. The compact design opens up new locations that were previously logistically inaccessible and accelerates the expansion of wind energy. Furthermore, the reduced material usage reduces the nacelle size and the mass in the tower head. This saves costs for the tower and foundation. Compared to gearboxes of the same power class from 2010, Revo enables a CO₂ reduction of up to 70 percent. Low-noise, second-generation plain bearings ensure compliance with European emissions regulations and increase operational reliability.

Global Development Expertise as a Success Factor

Revo is the result of close collaboration within Flender's global engineering network. By further developing existing technologies and using new gear materials, a unique prototype was created that delivers a competitive edge. At the heart of the concept is the combination of innovative technologies that together enable exceptional torque density – including the optimized combination of planetary stages and planet gears per stage, space-saving and noise-reducing plain bearings, and induction-hardened materials for maximum reliability. Extensive testing confirms the concept's performance.

"We have already doubled the torque density of our drives in recent years," says Tommy Rahbek Nielsen, President of Winergy. "With Revo and reaching the 300 Nm/kg mark, we are opening up new possibilities for our customers: more power in the same installation space or more compact components without compromising performance and reliability. Together, we define the right technology package for every project."

Premiere at the Voerde Plant

Following successful validation, the Revo concept is currently on display at the Winergy plant in Voerde. "Its compactness compared to previous systems is impressive," says Nielsen. "The prototype is intended to serve as a catalyst for developing the best solutions for upcoming projects with our customers. Our shared goal: to make wind energy as efficient and economical as possible."

"With Revo, we offer an answer to the requirements of current and future wind energy projects," adds Flender CEO Andreas Evertz. "This innovation is another step towards security of supply – and we are proud to present it."