Here's one for you -- my Sukup grain screener. The outer drum on this outfit turns one way and the inner turns the opposite. The contra-rotation is accomplished by using a ball bearing as a sort of planetary drive. Here's the front view of the drums:

 Notice that the outer drum is turned by two vee-belts that bear on the flat outer surface of the drum. The front of the drum is attached via four rods, to a plate that mounts the outer carrier of the ball bearing. The shaft that goes through the inner bearing is solidly attached to the inner drum, and that shaft is supported by a pillow block mounted ball bearing. Here's a close up of the support bearings and inner drum drive:

It took me a little time to figure out how they turned the drum backwards without using gears or pulleys/belts.