计入曲轴轴向运动的船舶柴油机主轴承混合润滑分析  

Mixed-lubrication Analysis on Main Bearings of Marine Diesel Engine Taking Crankshaft Axial Motion into Account

作　　者：魏立队[1] 陈浩 张志镭 胡以怀[1] 魏海军[1] WEI Lidui;CHEN Hao;ZHANG Zhilei;HU Yihuai;WEI Haijun(Merchant Marine College,Shanghai Maritime University,Shanghai 201306,China;Shandong Shipping Bulk Co.,Ltd.,Qingdao Shandong 266034,China)

机构地区：[1]上海海事大学商船学院,上海201306 [2]山东海运散货运输有限公司,山东青岛266034

出　　处：《润滑与密封》2023年第6期78-85,共8页Lubrication Engineering

基　　金：上海市科技创新计划项目(20DZ2252300)。

摘　　要：大型船舶柴油机曲轴在螺旋桨轴向推力激励下,轴向运动较为明显。为探究轴向运动对于支撑曲轴的主轴承润滑的影响,以一船舶柴油机曲轴-轴承为研究对象,同时计入螺旋桨轴向激励和柴油机自身激励共同引起的轴向运动、微峰接触(干摩擦),建立船舶柴油机主轴承的混合润滑模型。运用有限元法计算曲轴轴向运动,结合动力学方法,通过求解计入轴向运动和表面粗糙的平均Reynolds方程获得油膜压力,基于Greenwood-Tripp接触理论获得表面微峰接触压力。结果表明:计入轴向运动后,轴承的油膜峰值压力和油膜摩擦功耗均降低,微峰接触峰值压力均增加,但8个轴承的微峰接触摩擦功耗则是有的增加、有的减少,且影响显著,原因较为复杂;计入轴向运动后,最小油膜厚度、端泄流量、轴颈中心轨迹等的变化相对较小。因此,为更加全面、更加准确地预测大型船舶柴油机主轴承的混合润滑,必须计入轴向运动的影响。Under the axial excitation of the propeller,the axial movement of the crankshaft on the large marine diesel engine is obvious.In order to explore the effect of the axial movement on the lubrication of the main bearing supporting the crankshaft,a crankshaft-bearings system of a marine diesel engine was taken as the research object,and a mixed-lubrication model of marine diesel engine main bearing was established by considering the axial motion caused by propeller axial excitation and diesel engine self-excitation and the asperity contact(dry friction).The axial movement of the crankshaft was obtained by using finite element method.Combined with the dynamic method,the oil film pressure was obtained by solving the average Reynolds equation considering axial motion and surface roughness,and the asperity contact pressure was obtained based on the Greenwood-Tripp contact model.The results show that after taking into account the axial motion,the oil film peak pressure and oil film frictional power loss of the bearings are reduced,and the asperity contact pressure is increased.However,the asperity contact frictional power loss of some bearings increase and the others decrease among the 8 bearings.The influence of the axial motion on the asperity contact is significant,but the reasons are complicated.After taking into account the axial motion,the minimum oil film thickness,end leakage of bearing,journal center orbital path change little.Thus,the axil motion of the crankshaft must be considered to predict the mixed-lubrication of main bearings of the large marine diesel engine more comprehensively and more accurately.

关 键 词：轴向运动 主轴承 混合润滑 船舶柴油机 

分 类 号：TH113[机械工程—机械设计及理论]