The Front Bearing Ring .
There will be two support bearings on the wind turbine shaft. One at either end of the rotating blades and alternator assembly. This part will be bolted on in front of the blades to support the rotating mass from the front. The other (rear) support bearing is inside the rear magnet rotor. Again, this part is made from MDF and routed out to accept a 6004 size bearing.
Here are a couple of shots of the machined bearing ring with the 6004 bearing in place.