Study On The Engine Torsional Vibration Characteristics And Damper Development Based On The Transient Dynamics

The engine shaft system is a typical flexible shaft system, which includes crankshaft and other relevant moving parts. Torsional vibration of shaft system, which consumes effective power or even results in broken of shaft, is a problem during engine operating. So issues on torsional vibration are always concerned by engine designer. When a new type of engine is designed, careful research and validation of the crankshaft system torsional vibration is needed.To optimize the engine torsional vibration character of the EQ4H engine and guarantee the computational accuracy, the thesis simplified the engine crankshaft system into some concentration masses which only have rotational inertias and flexible shaft sections which connect the masses. Unigraphic software was used to model the EQ4H engine crankshaft system, and finite element method was used to compute the torsional equivalent system and get parameters of simplifed model. Holzer and modal analysis mothods were used to compute the crankcase free vibration and natural frequencies and relevant vibration modes, which was used to draw frequency map. The...