A STUDY ON KINEMATIC ANALYSIS AND DESIGN OF MULTIPLE INPUT SMALL CRANK MECHANISMS FOR FUNCTION GENERATION

Abstract

Increase in demand for power has necessitated the use of high-speed machinery, providing very small yet precise complex motions. Multiple-input small crank mechanisms have been shown to provide more complex output link motions. This dissertation briefly reviews the potential applications of simplest type of multiple-input small crank mechanisms i.e. two-input, five-bar mechanism Approximate kinematic equations are developed for the analysis and design of two-input, five-bar mechanisms driven by relatively small cranks. A perturbation technique is employed in the derivation of approximate equations. Exact expressions for output link motions have been obtained from the mechanism geometry. Expressions for finding static characteristics i.e. transmission angle and mechanical advantage have been developed. Both, exact and approximate expressions for finding angular velocities and angular accelerations have also been presented. Three design examples are presented to demonstrate the utility of the analytical development in the synthesis of five-bar mechanisms for first or higher order function -generation.