轴承润滑特性对船舶推进轴系校中的影响

摘要

径向轴承及推力轴承处边界条件的准确建立是船舶推进轴系校中计算的重点与难点。基于流体动压润滑理论，分析不同运行工况下考虑轴颈倾斜的径向轴承润滑特性，将轴承间隙、油膜厚度、支承基座及船体柔性以等效轴段挠度的形式计入轴系校中过程，并与刚性支承、弹性支承模型计算结果进行对比分析；计算因推力轴段转角、支承基座变形而引起的推力轴承附加力矩，并分析其对轴系校中的影响；建立轴承润滑与轴系校中耦合计算方法。结果表明：由径向轴承间隙、轴颈倾斜而引起的支点位置改变、润滑油膜厚度、推力轴承处附加力矩对轴系校中具有重要影响。%The configuration of the boundary conditions of journal and thrust bearings is one of the most im⁃portant and difficult parts of the procedure of marine propulsion shaft alignment. Based on the hydrodynam⁃ic lubrication theory, the lubrication performance of journal bearings is analyzed with consideration to mis⁃alignment. The equivalent deflection of the shaft element obtained from the bearing clearance, the lubricat⁃ing oil film thickness and the elasticity of the supporting structure are proposed during shaft alignment cal⁃culation, and the results of the alignment calculation using the equivalent deflection of the shaft element are compared with the scenarios of the stiff support hypothesis and linearly elastic support hypothesis. The bending moment acting on the thrust collar resulting from the misalignment or uneven distribution of the thrust pads in the circumferential direction is calculated, the influence of the additional moment on the shaft alignment is analyzed, and the coupling procedure of the shaft alignment calculation and bearing lu⁃brication performance calculation is established. The results show the important influences of bearing clear⁃ance, lubricating oil film thickness and additional moment on shaft alignment.