Research On The Design Of Hetero Ring Piston Seal Structure For Gap Sealing Hydraulic Cylinder

As one of the important control centers of high-end mechanical equipment,the hydraulic cylinder also begins to develop towards the direction of high speed,heavy load,high power and high frequency response with the increasing demand of the industry for the performance of mechanical equipment such as working speed,working load and working efficiency.Hydraulic cylinder dynamic response,power conversion efficiency,movement speed and other indicators are often restricted by the internal leakage,the key to improve the comprehensive performance of hydraulic cylinder is to optimize the hydraulic cylinder seal structure to control the leakage and ensure the lubrication performance of the seal interface.Compared with the traditional hydraulic cylinder,the gap sealing hydraulic cylinder adopts lubricating oil film sealing,which greatly reduces the friction between the sealing interface and improves the frequency response speed.However,the lack of traditional sealing ring also brings about the problem of large leakage.As an important branch of material science,heterogeneous materials are widely used in various construction machinery due to their superior mechanical and material properties.In this paper,according to the characteristics of the variable gap sealing hydraulic cylinder is mainly based on heterogeneous composite material deformation mechanism put forward a new kind of variable clearance heterogeneous ring hydraulic cylinder seal structure,the use of piston matrix and heterogeneous materials by different elastic deformation of the structure of radial bulge,in guarantee clearance sealing hydraulic cylinder under the premise of the lubrication performance of the sealing performance improvement.Aiming at the following problems,such as the action law of heterogeneous ring structure on the piston surface elastic deformation,the flow field flow and leakage variation of the seal clearance of heterogeneous ring piston hydraulic cylinder,and the optimization of heterogeneous ring seal structure based on fluid-solid coupling numerical simulation,the following work is mainly done in this paper.(1)Analysis of the influence of ring heterogeneous material on piston surface deformation.Combined with the working principle of the gap sealing cylinder and based on the equivalent inclusion principle,a mathematical model of the elastic field of the ring heterogeneous material piston was established.Through the model calculation,the influences of the structural parameters,distribution parameters and material characteristics of different heterogeneous ring on the radial shape variable and internal stress distribution of the gap sealing cylinder piston were analyzed.Through the above research,the influence rule of heterogeneous ring on the radial elastic deformation of piston has been mastered,which lays a foundation for the subsequent research.(2)Flow field analysis of heterogeneous ring piston seal with variable gap.Based on the early stage of the heterogeneous of piston ring elastic field model is established,combined with the actual working condition of hydraulic cylinder clearance seal structure parameters,further establish the hydraulic cylinder seal gap flow field of geometric model,the deformation curve of piston in heterogeneous materials and fluid mechanics theory,according to the theory of annular gap flow model for analysis,and through the gap flow field with FLUENT software of the geometric model for flow field simulation analysis,the analysis of the flow field under different heterogeneous thickness pressure,velocity distribution and the change of leakage.The results of simulation and theoretical calculation are compared.(3)Optimization of piston heteroring seal structure based on fluid-solid coupling.In hydraulic cylinder seal gap flow field model,on the basis of heterogeneous ring piston three-dimensional fluid-structure coupling model is established,analyzed and discussed heterogeneous ring structure parameters on the influence of the clearance seal leakage in the hydraulic cylinder,and analyzes the heterogeneous ring piston stress results under different working conditions,in order to reduce the clearance seal leakage in the hydraulic cylinder for the purpose of heterogeneous ring piston structure parameter optimization,in ensuring gap sealing hydraulic cylinder piston and cylinder friction pair under the premise of the lubrication performance,realized the leakage control.