计入曲轴及机体变形的主轴承动力学摩擦学耦合分析

Coupling Modeling Research on Tribological and Dynamical Behaviors of Main Bearing of Diesel Engine Considering Crankshaft Deformation and Block Distortion

为保证船用柴油机在低速重载工况下安全运行,曲轴及机体形变对主轴承润滑性能的影响不可忽略。以低速二冲程柴油机曲轴为研究对象,考虑曲轴及机体形变对主轴承润滑的影响,建立了曲轴-轴承系统动力学摩擦学耦合模型,采用编程计算对主轴承进行了动力学摩擦学耦合分析。结果表明:与考虑轴瓦弹性变形计算相比,考虑机体变形后,在一个工作循环内最小油膜厚度略有增加,最大油膜压力略有减小,端泄流量变化不明显;与仅考虑机体变形相比,考虑曲轴及机体变形后,最小油膜厚度明显减小,最大油膜压力明显增大,端泄流量变化不明显。

In order to ensure the safe operation of Marine diesel engine in low speed and heavy load,the influence of crankshaft deformation and block distortion on the lubrication performance of main bearing cannot be ignored.In this research,focusing on the crankshaft of a two-stroke low-speed marine diesel and taking the influence of crankshaft deformation and block distortion into consideration,a coupled simulating model of crankshaft-bearing system with tribo-dynamics is established,coupling analysis on tribological and dynamical behaviors of main bearings is carried out.The results show that,compared with those only considering deformation of bearing bush,the minimum film thickness is increased,the maximum film pressure is decreased,and the end flow-rate vary little over engine working cycle when considering deformation of block.Results show that when block deformation is considered,compared with those not considering deformation of crankshaft,the minimum film thickness is decreased,the maximum film pressure is increased,and the end flow-rate vary little over engine working cycle when considering deformation of crankshaft.