Apparatus for rotatably driving large cylindrical bodies

Apparatus for effecting rotational drive of a large cylindrical body carrying a semi-fluid load therein, which load upon rotation of the body about its principal axis becomes eccentric with respect to the vertical. Means are provided for supporting the cylindrical body with its principal axis extending in a substantially horizontal direction, and include at least a pair of first and second frictional drive rollers for the body. The rollers are spaced from one another as to enable engagement with points spaced about the circumference of the cylindrical body to alternate sides of the body axis. The rollers are powered by means which provide a driving torque at the roller carrying the larger portion of the load which exceeds the torque provided at the roller which carries a lesser load. The greater torque provided to the first roller is in accordance with the increase in normal force between this roller and the contacting body, in comparison with the diminished normal force at the alternate roller, due to the eccentricity of the load. Such unequal application of torque enables use of a maximized non-slipping tangential driving force at the first roller, without consequent slippage at the second roller. Differential means are also provided which enable variations in rotational speed between the said drive rollers, so that surface irregularities in the cylindrical body do not cause slippage at one or the other of the rollers.