Rope drum is a part of crane lifting gear. One or more ropes are unwinding from the rope drum body (depending on type of rope gearing), when subsequently the rope passes through the sheave set of the lifting gear.
PThe diameter of rope drum is usually determined by standardized line of diameters for drums and it is dependent on diameter of wound rope. The groove for rope, executed as continuous spiral along the shell, ensures the correct winding of rope to drum, when dimensions of this groove are determined in dependence on rope diameter.
In most cases the drum is mounted on one side in drum bearing and on another side on output shaft of gear box over the rope coupling, which can to a certain extent eliminate the incorrectness of lifting gear adjustment.