考虑径向-止推润滑耦合效应的柴油机翻边轴承热弹流润滑特性研究

Numerical Analysis on Thermo Elastohydrodynamic Lubrication of Flanged Bearings Considering Coupled Effect

柴油机翻边轴承包含径向和止推两部分,其支撑曲轴以及阻止曲轴轴向窜动的功用主要通过这两部分的润滑承载来实现.为进一步研究翻边轴承润滑特性,改善其服役性能,本文中考虑翻边轴承径向与止推部分在公共边界上的耦合润滑效应,提出了耦合润滑过程中需满足的热连续性条件,构建了翻边轴承热弹流润滑分析模型,并据此探究了径向部分偏心率和止推部分几何油膜间隙对轴承润滑承载力与表面温度的影响规律.研究结果表明,翻边轴承热弹流润滑分析中,在考虑径向-止推两部分公共边界耦合润滑效应时有必要引入热连续性条件;随着径向部分偏心率增大,各部分的承载能力增加,轴承表面温度升高;随着止推部分几何油膜间隙减小,径向部分承载力有所降低,止推部分承载力显著升高,各部分表面温度均升高.

The flanged bearing of diesel engine consists of journal and thrust parts and the function of supporting the crankshaft and preventing its axial movement mainly depends on the lubrication performance of these two parts.In order to further analyse the lubrication characteristics of flanged bearing and improve its service performance,this paper established a thermal elastohydrodynamic lubrication analysis model of flanged bearing,which considered the coupled lubrication effect of the common interface between the radial and thrust parts and proposed the thermal continuity conditions to be satisfied in the coupled lubrication process.Based on the model,the paper explored the influence of the eccentricity of journal part and the geometry oil film clearance of thrust part on the bearing capacity and surface temperature.Through the analysis of thermal elastohydrodynamic lubrication of flanged bearings,it was necessary to consider the thermal continuity condition when considering the coupled lubrication effect of the common interface between the radial and thrust parts.With the increase of journal eccentricity,the bearing capacity and the surface temperature of each part both increased.With the geometry film thickness of the thrust part decreased,the bearing capacity of the journal part decreased,the bearing capacity of the thrust part increased significantly and the surface temperature of each part increased.