The relationship between the pulley rope groove and the wire rope

The depth of groove should be selected so that the rope does not rub against the flange of the sheave or each other while entering running or leaving the groove. Angle of circular arc of the bottom of groove should not be less than 120 Degrees.

The grooves on the drum should be pitched so that there is clearance between neighboring turns of rope on that drum. The recommended clearances are 1.5 mm up to rope diameter of 28 mm and 3 mm for rope diameter above 28 mm.

The groove diameter of the pulley or sheave should always be larger then actual diameter of the rope. But if the groove diameter is too large the rope will tend to flatten and if it is too small pinching or rope will take place. The correct positioning is explained as under along with the tolerance and clearances on pully or sheave groove diameters.