Schaeffler (UK) Ltd · United Kingdom and Ireland

Wind turbines must be aligned optimally to the wind in order to prevent extreme loads and to provide the highest possible energy output.

Blade bearing (pitch bearing)

In order to control the power output of the wind turbine, the blade angle is always optimally adjusted to the wind speed via the blade bearing. Very high loads occur in some instances from the dynamic load of the rotor blades. These loads must be transferred securely via the raceways and the screw connections of the blade bearings into the rotor hub. Single or double row four point contact ball bearings with a cage are used here. The bearing can be produced with internal or external gear teeth or without gear teeth depending on the blade adjustment concept of the turbine.

Tower bearing (azimuth bearing)

A robust slewing ring is required in order to adjust the position of the nacelle to the wind direction. A particularly high level of reliability is achieved due to the slewing ring’s generous design. The wind load and the dynamic inertia forces are transferred securely and reliably via the raceways and the screw connectors into the tower head. Single or double row four point contact bearings with external gear teeth are mostly used here.

Azimuth drive/pitch drive

Wind turbines adjust automatically due to active systems. Geared motors and actuators convert the signals from the controller. Schaeffler Group Industrial offers bearing supports for slewing gears for nacelle and blade angle adjustment from one source:

• Input shaft – deep groove ball bearings
• Planet gears – full complement cylindrical roller bearings
• Output shaft – cylindrical roller bearings, spherical roller bearings, tapered roller bearings

Blade adjustment

In addition, the blade angle can be adjusted using electric or hydraulic systems. These use sealed plain bearings with the maintenance-free Elgoglide® fabric, protected against corrosion by means of the Corrotect® plating.