Dynamic Characteristic Simulation For KM385BZL Crankshaft

Crankshaft is an important part of an internal combustion engine. The working condition of a crankshaft has direct influence on the performance of an engine. Using computer simulation technology, this thesis is aimed to build a model of KM385BZL crankshaft and to analyze its dynamic characteristic in normal working condition.Firstly, a half crank model of this crankshaft is built. Two conditions are simulated, in which the model is forced by the connecting rod respectively at the time of combustion and at TDC in intake stroke. The displacement and stress curves of this model are gained and the static characteristic of this model is analyzed.Then, a simplified solid model of this crankshaft is built. Its natural frequencies and the corresponding mode shapes within 2000Hz on condition of free constraint are obtained by the method of model analysis. The natural vibration characteristic of this crankshaft is analyzed then.Finally, based on the theory of Timoshenko beam, a beam model of this crankshaft is built, which is compared with solid model. The results indicate that this beam model can meet the needs of calculation precision and calculation efficiency. With this beam model, the condition in which real loads are put on the crankshaft is simulated. The displacement curves,velocity curves,acceleration curves of the main journals and the pulley of this crankshaft and torsion vibration curve of the pulley are then gained. With these curves, the dynamic characteristic of the crankshaft is analyzed. The conclusion indicates that this crankshaft has good dynamic characteristic.