可变间隙密封液压缸异质环结构活塞形变研究

Research on Deformation of Heterogenous Ring Structure Piston of Variable Clearance Seal Hydraulic Cylinder

间隙密封液压缸因响应速度快受到了广泛青睐,其最大的缺点是泄漏量较大。结合可变间隙密封液压缸原理设计了一种新型的异质环结构,利用活塞基体材料和异质环的材料弹性变形差异产生的径向变形凸起结构提升间隙密封液压缸密封性能。建立环形异质材料结构引起活塞弹性形变的数学模型,并对活塞-异质环模型进行数值仿真。基于等效夹杂原理(EIM)对异质环不同结构参数、分布参数和材料特性下的活塞径向形变量进行计算。结果表明,软质环形结构能使活塞表面产生凸起状变形,硬质材料的环形结构能使活塞表面产生凹陷变形;异质环的长度、厚度等参数能改变活塞径向的最大变形量和最大形变所在的位置;随着异质环埋布深度的增加,活塞的最大变形量会逐渐减小。合理设置异质环的结构和分布参数以及材料特性,能有效减小间隙密封液压缸活塞-缸筒间隙的大小,从而降低泄漏量。

Clearance seal hydraulic cylinder is widely favored for its fast response speed,and its biggest disadvantage is the large leakage.In this paper,a new hetero ring structure is designed based on the principle of variable clearance seal hydraulic cylinder.The radial deformation bulge structure produced by the elastic deformation difference between the piston base material and hetero ring material is used to improve the sealing performance of clearance seal hydraulic cylinder.A mathematical model of the elastic deformation of the piston caused by the ring heterogeneous material structure is established and the piston heterogeneous ring model is simulated.Based on the equivalent inclusion method(EIM),the radial shape variables of the piston with different structural parameters,distribution parameters and material properties are calculated.The results show that the soft ring structure can make the piston surface deform convex,the hard ring structure can make the piston surface deform concave,and the length and thickness of the heterogenous ring can change the maximum radial deformation and the position of the maximum deformation.Setting reasonable structure,distribution parameters and material characteristics of hetero ring can effectively reduce the clearance between piston and cylinder.