KINEMATIC ANALYSIS AND DESIGN OF 3-INPUT, 8-BAR SMALL CRANK MECHANISM 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 mechanism i.e three-input, eight-bar mechanism. Approximate kinematic equations are developed for the analysis and design of three-input, eight-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. Expression for 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 eight-bar mechanisms for first- and higher-order function generation