Simulation and Analysis of the Crankshaft System of the High-Power Marine Engine

Abstract

The crankshaft is one of the most important parts of the engine and is likened to the "backbone" of the engine. In this paper, NL9340 high power diesel engine crankshaft system as the research object, the finite element free mode simulation model of crankshaft was established, and the inherent frequency and vibration mode of crankshaft were calculated. Through the rigid-flexible coupling finite element simulation of the crankshaft system, the dynamic and kinematic characteristics of the crankshaft system were analyzed. It was calculated that the load spectrum of each cylinder connecting rod journal and piston pin mainly fluctuated in the range of 20000 kN, in which the maximum exciting forces of the first connecting rod journal and the second connecting rod journal are above 30000 kN. On this basis, the static strength of the crankshaft was simulated and analyzed. The results show that the stress is the greatest and most concentrated at the over-rounded corner between connecting rod journal and crank. The maximum equivalent stress and deformation occur at the second cylinder connecting rod journal, which are 14.103 MPa and 8.3683 e^-3 mm respectively.