表面粗糙度对不对中滑动轴承润滑特性的影响

以活塞式航空发动机滑动轴承为研究对象,综合考虑轴颈倾斜和轴瓦表面形貌等因素对轴承润滑特性的影响,建立滑动轴承润滑分析模型;以高斯随机表面、分形曲面、非高斯随机表面分别模拟轴瓦表面的粗糙程度,分析轴颈不对中和表面粗糙度耦合作用下油膜压力、端泄流量、承载力和轴承力矩等参数随偏心率和转速的变化规律。研究结果表明:考虑轴瓦表面形貌后轴承最大油膜压力变大,最小油膜厚度有小幅度减小;随着偏心率和转速增加,最大油膜压力、端泄流量、轴承承载力、工作力矩均增加;随着偏心率增加,考虑表面形貌时(高斯表面、分形表面、非高斯表面)的轴承油膜压力、承载力、工作力矩均变大;随着转速的增加,考虑表面形貌时的轴承润滑特性均变大,尤其是高斯表面,润滑特性变化较明显。

Influences of Lubrication Characteristics of Misaligned Sliding Bearings by Surface Roughness Models

With the piston sliding bearing of type aero engine as the research object,considering the influence of the misalignment of journal and surface topography of bearing on the lubrication characteristics of bearing,the lubrication analysis model of sliding bearings was established.The Gaussian random surface,the fractal surface and the non-Gaussian random surface were respectively used to simulate the roughness of the bearing surface,the variation of oil film pressure,end discharge flow,bearing capacity and working torque with eccentricity and rotational speed under the coupling action of journal misalignment and surface roughness was analyzed.The results show that the maximum oil film pressure of the bearing becomes larger after considering the surface topography of the bearing,and the minimum oil film thickness is decreased slightly.With the increasing of the eccentricity and the speed,the maximum oil film pressure,end discharge flow,bearing capacity and working torque are all increased.With the increasing of the eccentricity,the oil film pressure,bearing capacity and working torque become larger when considering the surface topography(Gaussian surface,fractal surface,non-Gaussian surface).When considering the surface topography,the lubrication characteristics of the bearing are increased with rotational speed,especially the Gaussian surface,the lubrication characteristics change obviously.