The slew ring connects the tower to the nacelle of the wind turbine. Three further, smaller slew rings connect the rotor blades to the hub and align the rotor blades so that a maximum wind yield is guaranteed. Slew rings are forged and have a diameter of between two and nine metres.
This is not the only reason why they represent a great challenge for the machining process, during which gear hobbing is of particular importance. The aim is to achieve very plane and homogeneous surfaces in order to make grinding as simple and cost-effective as possible. As a result, a great deal is expected from the tools.
Here is a small selection: