Research On Key Technology Of Rubber-torsional Vibration Damper

Crankshaft system vibration is an important factor of engine vibration.The full support structure is generally adopted in engine crankshaft,and this structure with characteristic of large stiffness,usually,bending vibration does not occur within the engine work range.However,several long crankshafts with small torsion stiffness,which lead to the torsional vibration,is easier to be produced at engine speed range.At present,the most effective measure to reduce the torsional vibration of engine is to install a Torsional Vibration Damper(TVD)on the front of engine.In this paper,the rubber TVD of a 4-cylinder light diesel engine,which involves single and double parallel structure,was taken as the object,and the main structure,working principle and key technologies of TVD were regarded as the major clue.First,different structures and working princle of rubber TVD were introduced,then the torsional vibration characteristics of the crankshaft system were analyzed and calculated,and the calculation results show that the main harmonic torsional vibration affecting the shaft system.The research on the key technologies of Single-Mode TVD(SMTVD)includes the analysis of torsional vibration characteristics and rubber-ring failure.For the torsional vibration characteristics,first,a lumped parameter model of crankshaft with SMTVD was established,then,the kinetic equations of system were listed,finally,the torsional vibration calculation of system was finished.The results show that the damping effect of SMTVD was not obvious.For the rubber-ring failure,various performance indicators of a damper were calculated,and comparative experiments to determine the actual coefficient of friction were made,and the performance indicators of different parameters rubber-ring were simulated based on the orthogonal experimental method.The results show that the compression ratio is the crucial factor which affects the physical properties of the rubber-ring,when the compression ratio is constant,increasing the drum length leads to the addition of sliding torque of ring,and increasing the height of the drum causes ascent of pushing out force of it.The key technologies of Double-Mode Parallel TVD(DMPTVD)include the optimization of parameters related to DMPTVD and the analysis of the torsional vibration characteristics around the optimization.Firstly,the torsional vibration characteristics of the system with TVD were analyzed,the results shows that the DMPTVD damping effect for the system is more obvious and more stable than SMTVD.Secondly,the optimization model of the damper parameters was established,and optimal parameters were solved.Thirdly,the torsional vibration characteristics of the system around the optimization were analyzed,the results show that the optimized DMPTVD is more effective than the unoptimized.The research results of this paper have certain guiding significance for the research and development of rubber TVD for engine crankshaft.