These photos below show how to construct electric bearings made from common roller-blade/skateboard bearings which are used in the place of motor brushes in order to send current in and out of the spinning rotor.

This photo shows how to pry off one side of the metal bearing shields with a small screwdriver in order to replace the existing grease with conductive grease. Clean the bering first with carb cleaner, then lube with small amount of elelctrically conductive-type grease (either silver or carbon type). :


Electic bearing below is made with two bearings clamped together, with only one side of each bearing still with its protective sheild untouched (the outside of each), and the lead wire then clamped to the bearings. This is then cast inside epoxy (optional):


another view: