Research On Vibration Characteristic Of Large Diesel Engine Timing Chain System

Chain drive is a more widely used power transmission device for the machinery industry,and its applications cover many fields including industry,agriculture and military equipment.Chain transmission device because of its high efficiency,high reliability,accurate transmission,easy maintenance and other characteristics,in promoting the development of the national economy plays an important role in the process.In the diesel engine,the chain transmission device is mainly used in the timing chain transmission system,the diesel engine crankshaft through the timing chain drive device to drive the diesel camshaft,so that the inlet and exhaust doors can be opened and closed at the appropriate time to ensure that the diesel engine can be normal suction and exhaust.However,the chain drive also has its flaws,the engagement impulse excitation and the polygon effect excitation make the vibration problem of the chain drive system particularly prominent,and with the diesel engine gradually toward the high speed,heavy load,the transmission power is increasing,which aggravates the vibration problem of the diesel engine timing chain drive system.Therefore,it is of great theoretical and practical significance to study the dynamics and vibration characteristics of the diesel engine timing chain drive.Based on the multi-body dynamics theory,the simulation and analysis of the dynamic and vibration characteristics of the system are carried out by using the multibody dynamics simulation software ADAMS.The simulation results show that the 5S50-ME diesel engine's timing chain drive system is used as the research object.The main contents of this paper are as follows:(1)Analyze the engagement impulse excitation and the polygon effect excitation from the theory,and analyze the reason why the chain drive system is running unstably and the vibration is generated from the kinematics point of view.(2)Analyze the structural characteristics of the diesel engine timing chain drive system,builds the 3D solid model of the system with the 3D modeling software SolidWorks.(3)Based on the theory of multi-body dynamics and contact theory,the multi-body dynamics simulation model of diesel engine timing chain drive system was established.The contact force of chain and sprocket,the lateral vibration and longitudinal vibration of the chain were analyzed and the influence of each parameter on the characteristics of diesel engine timing chain drive system is studied.(4)Based on the idea of optimal design,ADAMS optimization design module is used to optimize the diesel engine timing chain transmission system.