Mechanics of Roller Chain-Sprocket Contact: Observations About the Contact Phenomena and Load Distribution

Abstract

Abstract In a companion paper (“Mechanics of Roller Chain - Sprocket Contact: A General Modelling Strategy” submitted for presentation at this conference), a new theoretical model to describe the quasi-static contact phenomenon between a roller and sprocket is developed from first principles. The new model includes the external loading conditions, the curvature difference between die roller and the seating curve, the net error in the chain pitch (defined as the error in the chain pitch minus the error in the sprocket pitch), and Coulomb friction between the tooth and roller, the roller and bushing, and the bushing and pin. No assumption regarding the pressure angle at each contact point is made — rather the pressure angle at each contact point is calculated during the solution. In this paper we present results generated by a computer simulation based on the new model. A comparison with experimental data taken from the literature (Naji and Marshek. 1983) indicates that excellent quantitative prediction of load distribution is possible. The simulation results suggest several practical observations about chain performance (including effects of friction, manufacturing tolerances, wear, and the incorporation of idler sprockets) and these are presented and discussed.