不同造型微坑的动压润滑性能分析

The Hydrodynamic Lubrication Performance of Different Modeling Micro-pits

在雷诺方程的基础上对缸套-活塞环润滑系统进行数学建模并对单个微坑的润滑状况进行分析计算,运用MATLAB软件对圆形坑口的球形、椭球形、圆锥形及椭圆抛物面形微坑的润滑状况进行有限元分析,以期获得最佳微坑造型。结果表明:坑口形状圆形优于非圆形;在一定范围内适当加深微坑能够有效增加油膜厚度、增加储油量、减小最大动压力;在相同的条件下,椭圆抛物面形微坑在4种微坑造型中润滑效果最佳,其油膜承载能力最强,且其压力场呈反对称分布,使得润滑油和磨屑将更加容易进入微坑内部从而能够有效避免产生干摩擦,促进流体动压润滑。

The mathematical model of the cylinder-piston ring lubricating system was set up and the lubrication performance of the single micro-pit was analyzed and calculated based on Reynolds-equation. The lubrication performances of different models of micro-pits such as sphericity, ellipsoid, circular cone and elliptic paraboloid were analyzed by MATLAB to get the best one. The results indicate that circle pithead has better effect to decrease the maximum dynamic stress than non circular pithead, and it can effectively increase the oil film thickness, increase oil reserves and decrease the maximum dynamic stress by deepening the micro-pits properly within a certain range. Under the same conditions, the micro-pit of elliptic paraboloid has the best lubrication performance among the four models, so it has the strongest load capacity. Its stress field is antisymmetric distribution, the oil and abrasive dust can easily go into the micro-pits, so the dry friction can be effectively avoid and the hydrodynamic pressure lubrication can be promoted.