Analysis Of Torsional/Bending Vibration Of Diesel Engine And Design Of Its Complex Crankshaft Damper

Studies have showed that, torsional vibration is the main reason to damage thecrankshaft, and bending vibration is one of the main excitation sources to induceengine noise. The torsional-bending complex damper, made up of one torsionaldamper and one bending damper, can suppress torsional vibration, bending vibration,as well as engine noise. This paper uses simulation and experiment methods toresearch torsion/bending vibration of diesel engine and its composite damper design.Firstly, a6-cylinder in-line diesel engine is taken as the object. Use thetraditional discrete method to study the torsional vibration and bending vibration ofcrankshaft system without damper. The study finds that, the equation of motion of thebending vibration, with some proper simplified, can be transformed into the sameequation as the torsional vibration. So designing the complex damper can analyze oneof the two vibrations.Secondly, this paper chooses the parallel form of torsional-bending damper asresearch object, model two of the equivalent models of the complex damper: therubber-rubber complex damper and silicone-rubber complex damper. Analyze optimalparameters design method of complex damper, as well as the influence of theparameters’ deviation. Base on the Silicone damper of the engine, a new rubberdamper is designed to form torsional-bending damper.This paper also use the multi-body dynamics software AVL—EXCITE Designerto calculate the crankshaft vibration in parallel, analyze the torsional vibration of thecrankshaft with and without the silicone oil damper.At last, a rubber damper is manufactured, measure the torsion vibration andbending vibration, as well as noise of the crankshaft free part, at state with onlysilicone damper as well as silicone-rubber complex damper. Results have showed that,the torsional-bending complex damper have some better effect on torsional vibration,bending vibration and noise of crankshaft free part.