Simulating the dynamic behavior of chain drive systems by advanced CAE programs

摘要

Due to the increased requirements for chain drive systems of 4-stroke internal combustion engines CAE tools are necessary to design the optimum dynamic system. In comparison to models used in the past the advantage of the new model CDD (Chain Drive Dynamics) is the capability of simulating the trajectory of each chain link around the drive system. Each chain link is represented by a mass with two degrees of freedom and is coupled to the next by a spring-damper element. The drive sprocket can be moved with a constant or non-constant speed. As in reality the other sprockets are driven by the running chain and can be excited by torques. Due to these unique model features it is possible to calculate all vibration types of the chain, polygon effects and radial or angular vibrations of the sprockets very accurately. The model includes the detailed simulation of mechanical or a hydraulic tensioner as well. The method is ready to be coupled to other detailed calculation models (e.g., valvetrain systems, crankshaft, etc.). The high efficiency of the tool predicting the dynamic and acoustic behavior of a chain drive system will be demonstrated in comparison to measurements.