For example, X-ray tubes with a rotating anode have a bearing system for bearing the rotating anode, in particular a fluid metal lubricated system with radial and axial bearings, supported on both sides of the bearing. 
U.S. Pat.  No.  6,064,719 relates to a rotary-anode X-ray tube having an axial tumble disc bearing system to reduce the friction losses in a hydrodynamic bearing system.  The tumble disc bearing system comprises an inner bearing member and an outer bearing member, the inner bearing member having three bearing portions, wherein the first or the second bearing portion can perform a swinging motion about the axis of rotation during the rotation of the two bearing members.  The tumble disc may be to connect to a still standing shaft with a pin engaging with a recess of the shaft.