Belt Slip—A Unified Approach

Abstract

Slip measurements on thick flat belts, V-belts and V-ribbed belts running on small pulleys reveal that the slip is much higher than can be predicted with classical creep theory. Shear creep plays an important role and special care must be taken when analyzing the shear deflection of the V-belt and the ribs of the V-ribbed belt. Other mechanisms are present as well. The behavior in the seating and unseating regions changes the direction of the frictional forces in these regions on the driver pulley. A unified slip theory is presented for flat belts, V-belts and V-ribbed belts considering creep, shear, seating/unseating and compliance. Measurements and theory fit very well for practical tension levels. At low tension the measured slip is higher than the predicted one for V-belts and V-ribbed belts, which probably depends on the poor fit between the belt and the grooved pulley.