Investigation Of Torsional Vibration And Torsional Vibration Damper Matching For Diesel Engine

The torsional vibration in crankshaft system during the work of reciprocating internal combustion engine will cause crankshaft and related parts damage early, effect the safety and reliability of engine operation, as well as produce exceeding vibration and noise. In order to solve this problem, based on the domestic research achievements, a rubber torsional vibration damper used in diesel engine has been deeply investigated. Because of the inherent inertia and elasticity of shafting, the periodic excitation from gas pressure in internal combustion engine cylinder will cause the resonance of shafting. On the precondition of assuring a certain calculation precision, the continuously distributed shafting can be simplified to be a dispersed system consisted of some concentrated movement inertia and torsional elastic shafting. The excitation torque caused by shafting torsional vibration can be converted to be an infinitude series consisted of oscillation with different initial phases, different amplitudes and different periods. Under the specified precision, the real value can be approached by the sum of some items of infinitude series, and the resonance amplitude and accessory torsional vibration stress of the crankshaft can be calculated at the resonance speed. When the torsional vibration amplitude and stress exceed the limit, the rubber torsional vibration damper should be designed to reduce the amplitude within the permitted range.In this paper, a shafting model of 6106 type diesel engine was constructed by using traditional torsional vibration calculation method and the American Parameter Company's 3-D design software – a powerful pro/engineer. By using the model analysis function and finite element modular, the conversion of torsional equivalent system of the shafting was made. By using the traditional energy method, the forced vibration of shafting was calculated and the bolt strength of the crankshaft and flywheel was verified. Based on the torsional vibration calculation and experiment, a rubber torsional vibration damper had been designed to reduce the torsional vibration of 6106 type diesel engine and to increase the safety coefficient of crankshaft and flywheel. All thework involved in this paper had been verified by the torsional vibration experiment on the crankshaft and intensified experiment on the whole engine.