If a central component fails through damage, long lasting turbine downtimes can occur – which in turn lead to wind power production losses. Gearless or direct drive turbines are equipped with fewer components and are therefore potentially less susceptible to damage.

Fraunhofer IWES and the FITT research team plan to develop a new gearless drive concept for drive trains. “Material and cost savings are to be achieved through a modular and compact construction, along with increased turbine robustness and less damage susceptibility,” said Patrick Tober, Fraunhofer IWES component and production project leader.

The core component of the new concept is its integrated generator construction. The rotor blades are attached directly to the generator and not as previously connected with the hub in front of the nacelle. It also has a lightweight construction.

The research project will also examine other aspects such as fully enclosed or open generator design, reduced component numbers and the cooling system with regards to cost reductions and increased performance. It will also look into how reductions in the mass of the tower head and an integrated lightweight design can be achieved. Another focus of the project is the standardization of components and interfaces, as well as series production possibilities. The hub generator is intended be used on direct drive turbines in the output range of 3MW upwards. The project has a total budget of €155 million and will run until December 31st, 2015. 

A simplified hub generator model was presented at the EWEA 2013 in Vienna, Austria. The exhibit shows a generator to a scale of 1:5.