考虑轴颈倾斜和表面粗糙度的水润滑橡胶轴承弹流润滑分析

Analysis of elasto-hydrodynamic lubrication of water-lubricated rubber bearings with journal tilting and surface roughness

本文以水润滑橡胶轴承为研究对象,采用表面粗糙度测量仪对其表面粗糙度进行了测量,确定了表面粗糙度的分布函数;考虑轴颈倾斜和表面粗糙度的影响,建立润滑数学模型,并推导了水膜厚度方程;采用有限差分法,研究了不同倾角及表面粗糙度对膜厚和膜压的影响,并与无倾角、表面光滑的轴承进行对比分析,最后分析了不同倾角、粗糙度幅值和波长下的最小膜厚及最大膜压。研究结果表明:考虑倾角及粗糙度时的膜厚沿周向呈连续的波状分布,沿轴向逐渐减小;膜压沿周向有微小的连续波动,沿轴向呈尖角形状且分布极为不均;与无倾角表面光滑的轴承相比,倾角和粗糙度使得最小膜厚更薄,膜厚差值变大,膜压迅速增大,出现轻微的局部压力突变。表面粗糙度幅值和波长对水膜厚度均有较为明显的影响,粗糙度幅值对水膜压力的影响也较大。

This study is aimed at water-lubricated rubber bearings,the surface roughness of which was mea?sured by surface roughness measuring instrument,and the distribution function of the surface roughness was determined by considering the influence of journal tilting and surface roughness.The mathematical model was constructed and the water film thickness equation was deduced by adopting the finite difference method.The effect on film thickness and pressure under different tilt angles and surface roughness was studied,the re?sults of which were compared with those of the smooth surface bearings without tilt angles.Analysis of the minimum film thickness and maximum film pressure under different tilt angles,roughness amplitudes and wavelengths shows that,with consideration of tilt angle and surface roughness,the film thickness displays a continuous wave-like distribution in the circumferential direction,and gradually decreases in the axial direc?tion.The film pressure has a slight continuous fluctuation circumferentially and exhibits a sharp angular and extremely uneven distribution axially.In comparison with the smooth surface bearing without a tilt angle,the tilt angle and roughness reduce the minimum film thickness,enlarge the film thickness difference,increase the film pressure rapidly and cause a slight sudden change of the local pressure.The surface roughness amplitude and wavelength have a significant effect on the water film thickness while the roughness amplitude has a greater influence on the water film pressure.