Axial forces of a V-belt CVT

A simple analytical formula is derived for the axial forces of a V-belt CVT drive. For the driver pulley axial force, belt tension is assumed to be constant by self-locking. For the driven pulley axial force, the whole arc of contact between the belt and the pulley is divided into two regions; (1) inactive and (2) active area. The sliding angle ø for the belt friction is approximated as ø=0 in the active area. It is found that the results of the new formula are in close agreement with the exact solution. The new formula is suggested for the V-belt CVT design due to its simplicity and sufficient accuracy.