液压缸活塞微织构化表面动压润滑性能理论研究

Theoretical stydy on hydrodynamic lubrication performance of micro-texture on the hydraulic cylinder piston surface

为研究液压缸活塞微织构化表面的动压润滑性能,在液压缸活塞表面加工开口形状为圆形、椭圆形、正方形、正六边形的微织构,利用雷诺方程对活塞表面与液压缸缸筒内圆之间的流场进行数学建模,并采用MATLAB软件进行仿真计算,研究微织构开口形状、活塞运动速度及微织构深径比对活塞表面动压润滑性能的影响。结果表明,在活塞表面加工4种不同开口形状的微织构均可改善活塞表面的动压润滑性能,其中椭圆形微织构的改善效果略差;随着活塞运动速度的提高,不同形貌微织构表面的摩擦因数均增大,活塞表面动压润滑性能变差;圆形微织构的深径比为0.009时,活塞表面的动压润滑性能较佳。

In order to study the hydrodynamic lubrication performance of the hydraulic cylinder piston textured surface, this paper, considers four micro-texture opening shapes （circle, ellipse, diamond, and hexagon） on the hydraulic piston surface and using Reynolds equation, establishes the mathematical model of the flow field of a single micro-texture control unit between the piston surface and the inner circle of the cylinder. MATLAB is used for numerical calculations, and the influence of micro-tex- ture opening shape, velocity of piston, and micro-texture depth-to-diameter ratio on the hydrodynamic lubrication performance of the piston surface is studied. The results show that, all the four opening shapes of micro-texture on the piston surface can improve the hydrodynamic lubrication performance of the piston surface, and among the four opening shapes, elliptical micro-texturing has the poorest effect. With the increase in velocity of piston movement, the friction coefficient of micro-texture sur- faces increases, and the hydrodynamic lubrication effect becomes worse. The optimal depth-to-diame- ter ratio of circular micro-texture is 0. 009, in which the hydrodynamic lubrication effect is the best.