Synthesis of Wrapping Cams

Abstract

This paper describes a technique for synthesizing a force-generating mechanism composed of a cam wrapped by a belt or chain. Such mechanisms will hereafter be referred to as “wrapping cams.” Synthesis methods for two configurations of this mechanism are presented. In the simplest case, the cam is wrapped by a belt or chain under constant tensile force, producing a nonlinear torque at the cam. In the second case, the cam is under constant torque, producing a nonlinear belt or chain force. While wrapping cams are far less common than cams that generate specified follower displacement functions, applications for wrapping cams exist in counter-balancing mechanisms, exercise equipment, and process machines.