Usually two bearings are used to support the rotating mass of such a system.  For the AWE 900 series turbines a concept of one bearing with a large diameter was chosen.  The large diameter allows the lines of force to go from the rotor blades (large diameter) to the large diameter generator rotor without being concentrated into a small bearing. The bearing is hollow, allowing the servicing of the rotor hub.  It is possible to inspect the active pitch regulated blades from the inside without the use of a crane.

The main bearing is a specially designed three row cylindrical roller bearing of the large diameter. The inner non-rotating ring is mounted to the generator stator. The outer rotating ring is mounted between the hub and generator rotor. The bearing takes axial and radial loads as well as bending moments. Entrance to the hub is achieved through the inner-bearing ring. The bearing is provided with a fully automatic lubrication system monitored by the turbine controller.