不同工况下内燃机曲轴轴承的润滑性能

Lubrication Performance of Crankshaft Bearing for Internal Combustion Engine at Different Working Condition

以4冲程4缸柴油机为研究对象,进行了不同工况下的曲轴轴承负荷计算和润滑分析.连杆轴承负荷计算采用动力计算方法,应用整体曲轴梁单元有限元方法计算曲轴各主轴承负荷,采用动力学法进行曲轴轴承的润滑分析.结果表明:不同内燃机工况下,曲轴轴承负荷和润滑性能在一个内燃机工作循环中的变化规律和对应时刻的数值存在较大差异;曲轴轴承润滑性能的最不利情况不一定出现在内燃机标定工况;相同工况下连杆轴承与主轴承润滑性能之间以及各主轴承的润滑性能之间也存在较大的差异.因此,内燃机曲轴轴承设计时,如果仅分析标定工况下的某一曲轴轴承润滑性能将不够全面合理,需要进行不同工况下各曲轴轴承润滑性能的分析计算.

Load and lubrication of crankshaft bearing at different working conditions in a four-stroke four-cylinder diesel engine were analyzed.Load of connecting-rod bearing was calculated by the dynamic cal-culation method,load of all crankshaft main bearings were calculated by whole crankshaft beam-element finite element method,and lubrication of crankshaft bearing was analyzed by the dynamic method.Re-sults show that large difference in the changes and numerical value at corresponding moment of load and lubrication performance of crankshaft bearing in an engine working cycle at different working condition is presented.The worst lubrication case for crankshaft bearing may not occur in engine rated condition.Large difference between the lubrication performance of connecting-rod bearing and that of main bearing,and among the lubrication performances of different main bearings is presented.Thus,it is unreasonable for only analyzing the lubrication performance of certain crankshaft bearing in the design of the crankshaft bearing.Analysis on lubrication performance of all crankshaft bearings at different working conditions is needed.