Simulation of timing chain drives using ketsim

In modern combustion engines timing chains are used to actuate camshafts, balance shafts, diesel injection pumps, oil pumps and auxiliaries. Optimizing the engine design with respect to operation reliability, efficiency, noise and acoustics requires a profound knowledge of the vibrational behavior of all chain drive components. The amount of expensive experiments can be significantly reduced by analyzing and studying such systems using computer simulation. At the Institute of Applied Mechanics at the Technical University of Munich, Germany, a multi body simulation program has been developed to compute the dynamical behavior of complex timing chain drives. It is used by several members of the German FVV (Forschungsvereinigung fuer Verbrennungskraftmaschinen), e.g. Porsche, Audi, BMW, DaimlerChrysler and others. This paper describes how the components and the effects of timing chain drives are modelled within the simulation tool. The underlying models are to be explained but also a comparison between simulation and experiment will be presented for a DaimlerChrysler 8-cylinder diesel engine (OM628) which drives the Mercedes-Benz S-Class (S 400 CDI).