二冲程船舶柴油机主轴承润滑数值分析

Main bearing lubrication simulation of two-stroke marine diesel engine

为准确分析某大型二冲程6缸船舶柴油机主轴承润滑状况,将有限元法与非线性多体动力学相结合,对主轴承润滑状况进行弹性流体动力润滑(EHD)分析.计算整个工作循环下的各主轴承载荷、轴心轨迹、偏心距和最小油膜厚度及油膜压力分布等参数.结果表明,2#、3#、5#和6#主轴承在一个周期内出现3次载荷峰值,最大载荷约1500 kN;6#主轴承载荷最大,为1575 kN,其轴承偏心距也较大;2#轴承油膜厚度最小,为4.75μm,此时油膜压力较大,偏布于轴瓦边缘;2#主轴承润滑状况相对较差.

To analyze the main bearings lubrication condition of a large two-stroke 6-cylinder marine diesel engine,the elasto-hydrodynamic lubrication of the main bearings was simulated combining finite element method with nonlinear multi-body dynamics.The main bearings load,orbit path,eccentricity,minimum oil film thickness and average film pressure in a working cycle were calculated.Results show that No.2,No.3,No.5 and No.6 main bearings force shows three peaks in one working cycle,and the maximum force is up to 1500 kN.The force of No.6 main bearing is the maximum at about 1575 kN,and its eccentricity is large comparably.The minimum thickness of oil film is in No.2 main bearing and its value is 4.75 μm,at the same time,the film pressure is large comparably and around the edge of shell.The lubrication condition of No.2 main bearing is relatively poor.