When the propulsion shafting system of marine diesel engine is designed, the vibratory stresses on shafts should be reviewed and be satisfied with limits which are laid down by classification societies. In addition, the torsional vibration aspects for crankshaft of main engine are requested to be checked by engine designers.
Especially, for the 4, 5, and 6-cylinder engines, the 2nd order moment compensator(s) may be installed to compensate the external moments of engine and not to excite the hull girder vibration. This moment compensator which is mounted on fore and/or after-end of engine is driven by the roller chain drive for some of MAN B&W 2-stroke diesel engines. While the engine is running, the roller chain is worn down, which causes the extension of roller chain. The chain therefore should be checked and tightened by periods in order to keep its functionality.
However, when the torsional angular acceleration of chain drive exceeds the certain limit, the chain will suffer the excessive slack and transverse vibration. This may cause fatigue, wear or damage on the chain and the chain ultimately may be broken.
The research object of this thesis is to review factors which affect on the angular acceleration of chain drive and to find out how to decrease the angular acceleration of driving chain by checking factors which have a major contribution to acceleration reduction using the statistical method of DOE(design of experiment), correlation analysis and regression analysis methods.