Energy Loss and the Choice of Damper of Torsional Vibration Combustion Engines

Abstract

The crankshaft is exposed to numerous external extortions which generate bending, axial and torsional vibrations. Torsional vibrations are especially dangerous for a safe operation. They are generated by strongly dynamic loads, which come from the combustion processes of fuel-air mixture in cylinders and from the elements of drive system, and engine accessories. Until recently this problem concerned mainly the engines of high power, where dynamic effects generated the vibrations with amplitudes exceeding the limit values, which in effect led to failure of the engine. Crankshafts also significantly increased their torsional elasticity because of the common trend of reducing the engine mass. It resulted in the necessity of using the elements reducing the amplitude of torsional vibrations of the shaft. Rubber torsional vibration dampers are commonly used for this purpose. The author observed that while choosing torsional vibration dampers, the producers concentrated only on the criterion of reducing the amplitude of torsional vibrations below limit values. They forgot that the optimization criterion can be expanded in such a way so that a better effect can be obtained. What is more, safe and economical operation of the engine could be provided.