Aim of the project is the development of a flexible CFRP torque shaft in bending direction to securely transfer a high torque load. Efforts focus on the optimization and prediction of failure of the load introduction area.
For ENVISION’s new 3.6 MW two-bladed direct drive offshore wind turbine SchäferRolls GmbH & Co. KG, Renningen, and IVW develop the 8.6 m CFRP torque shaft for load transfer from rotor to generator. The project started in autumn 2010 and includes design and FE analysis for the rotor and generator end steel flanges and the CFRP torque shaft and also the CFRP material qualification. Due to a special design feature the torque shaft directly transfers the torque and acts as a flexible coupling to allow for position correction between wind turbine rotor hub and the generator, hence its name “FlexShaft”. IVW came up with a concept, then worked out a more detailed design including extensive finite element analyses. SchäferRolls manufactured a first prototype based on this work which is meanwhile installed in ENVISION’s E128 wind turbine machine.