A virtual prototype of a constrained extensible crank mechanism: Dynamic simulation and design

Abstract

Dynamic response of mechanical systems containing rigid links connected by joints is affected by the velocity and mass of the systems components as well as by the presence of clearance or impact between components. Accurate simulations of such systems are increasingly important due to their wide application in engine design, knitting machinery or single and dual-arm robotic systems, as well as for their initial and optimised design. A virtual prototype of a newly developed extensible crank mechanism (applied to the design development of a bicycle crank) is presented in this article and its dynamical behaviour is analysed. The equations of motion of the extensible crank, constrained to either a circular or an elliptical path, are considered. Accurate simulation of the constrained extensible crank mechanism explores its performance and behaviour under the combined effect of different parameters such as clearance and impact. A three-dimensional finite element model is used to study the flexural behaviour of the extensible crank under the maximal loads that causes its motion.