A. H. Gears was asked to design and build a wind turbine gearbox for a Christchurch company Windflow Technology.

The gearbox needed to have a 30:1 ratio and a design life of 20 years. Input power is 109,000 Nm at 48.2 Rpm and a max braking torque of 189,000 Nm. The final design incorporated 3 planetary stages and 1 parallel gear stage and the use of some very innovative designs. One is the torque limiting system designed by Geoff Henderson, Company Director of Windflow. It allows high loads caused by wind gusts to past through the gearbox but without applying the loads to the gears and bearings. This allowed us to build a more compact gearbox with confident load data to design around.

Check out www.windflow.co.nz for details of the final product.

Click here to download animation of the turbine gearbox in action.