A Geartrain Model for the Dynamic Analysis of a Motorbike Timing System

This work deals with the elastodynamic model of the geartrain that drives the cam-valve mechanisms of a motorbike engine timing system. The gear torsional vibrations are simulated by means of a lumped parameter model which takes into account the parametric excitation due to the time-varying meshing stiffness, the tooth separation phenomenon and the lubricant squeeze effect between approaching teeth. In order to get insight into the dynamics of the timing system, and to help the development of the geartrain elastodynamic model, several experimental tests were carried out. The experimental procedures are here illustrated together with the signal processing techniques. The comparison between numerical results and experimental measurements shows that the effectiveness of the model is satisfactorily assessed. The model can predict and interpret the actual dynamic behaviour of the system; therefore, it can be used as a tool for the design optimisation of the motorbike timing system. © (2006)...