Haven't got a clue, but if the four hinged doors cover anything I would guess they must remain on top, so it would be used in a horizontal plane, on a vertical shaft. The square made by the door covers doesn't seem strong enough as a drive, and any resistance would cause damage, so I guess it revolves freely. There appears to be wear marks on the round boss, as though it sits on a collar of some sort.
A close up of the cam arrangement would be useful, and the angle piece attached to each of the doors - what do they do????