KINEMATIC SYNTHESIS OF PLANAR ADJUSTABLE SIX BAR MECHANISM FOR SPECIFIED OUTPUT

Abstract

A method for the synthesis of planar adjustable six bar mechanism with a slider output is presented. The multi-loop six bar linkage considered here is a series combination of two four link mechanisms with first phase having regular RRRR linkage. The second phase consists of a slider crank with the slider being the output member. An analytical method is presented for the kinematic synthesis of a planar four bar adjustable mechanisms using Chebychev’s accuracy points and Fruedenstein’s equations for three point function generation that satisfy a given input output relationship. The length of the coupler link is taken as the adjustable parameter. An analytical method of computing the value of this variable for a four bar crank rocker mechanism as well as a slider crank mechanism is presented. A numerical example explains the synthesis procedure developed in which a function to be generated is considered. The unknown link lengths of the mechanism are then found for given range of input and output link parameters and assumed link length. The value of the adjustable length of the coupler is then computed and the results are presented numerically as well as graphically. The method adopted is coded using MATLAB for quick computation and ease of use. The motion and the path generated by the designed mechanism is found for different values of the adjusted parameter.