Synthesis of stephenson-III mechanism for generating a coupler curve with up to five acceleration poles

This article utilizes an analytical method for the dimensional synthesis of a planar six-bar Stephenson-III mechanism for generating a coupler curve with up to five acceleration poles. The parametric equations expressing the loci of the acceleration pole on the fixed link and the coupler plane of the Stephenson-III mechanism driven by a crank with a constant rotational speed are derived. The desired coupler point of a given path generator passing through two or more acceleration poles should be a multiple point on the locus of the acceleration pole described on the coupler plane. Using the parametric equations and the multiple point on the locus of the acceleration pole on the coupler plane, a procedure is proposed for synthesizing the Stephenson-III mechanism for generating a coupler curve with up to five specified acceleration poles that accord with the specified crank angles. Two examples are provided to illustrate the feasibility of the proposed method.