Design Equations for a Speed and Torque Controlled Variable Ratio V-Belt Transmission

A type of V-belt drive which shifts ratios in accordance with input speed and output torque has been successfully employed as the transmission for vehicles ranging from snowmobiles to compact automobiles. Increasing popularity of this kind of transmission has created the need for more reliable criteria to be used in its design. This paper presents a derivation of design equations for a symmetrical V-belt drive in which centrifugal control is governed by an expanding garter spring and torque control results from a helical cam. Experimental results are included which support the validity of these equations.