Kinematic and Static Force Analysis of Rocker-Pin Jointed Silent Chains with Involute Sprockets

Abstract

A quasi-static model has been developed for a silent (inverted-tooth) chain drive incorporating a rocker-pin-jointed chain and involute-toothed sprockets. The kinematic effects of rocker-pin clearances and link/sprocket engagement are modeled and the influence of various model parameters on the chain drive torque-ratio variation, due to chordal action, is examined. In some cases, this variation is found to be less than that for equivalent pin-jointed chain drives. Additionally, the center distances corresponding to the maximum and minimum torque variation are not fixed, as in the case of a pin-joined chain. An optimization method is used in determining the governing geometric constrains as multiple joint configurations can occur, given the rocker-pin joint clearances. The resulting system of equations is fully constrained for a physically consistent chain configuration.