重载高速间隙密封伺服液压缸非均质摩擦界面弹流润滑机理与结构优化设计研究

Heavy-duty and high-speed servo hydraulic cylinders in our country depend on import in long-term, and the import rate climbs up to 90%. How to reduce the friction and enhance frequency response are the major technical difficulties to be resolved. The existing clearance seal is poor in eccentric resistance and dynamic and static characteristics and wear seriously under heavy duty. This project takes the decrease friction of clearance gap seal servo hydraulic cylinder in the high-speed heavy-load as the goal，and combines the research contents of elastohydrodynamic lubrication (EHL) and metallic inclusion theory to produce the particle reinforced copper matrix composite coating with controllable elasticity deformation, put forward the thinking of controllable clearance of hydraulic cylinder piston, and resolve the following three issues: (1)The elastohydrodynamic lubrication characteristic of the heterogeneous friction interface by reciprocating motion of the high-frequency and heavy-load servo hydraulic cylinder; (2)The coupling optimization method between geometrical shape of the piston surface and the subsurface particle reinforcement features; (3) Elastohydrodynamic lubrication test system which conforms to the actual working condition of clearance gap seal servo hydraulic cylinder. Through the above study, it is to settle the theoretical and technical issues about the friction characteristics and friction reduction of clearance gap seal of the high-speed and heavy-load servo hydraulic cylinder under unbalance conditions, enrich the development connotation of clearance seal, expand the application scope of elastohydrodynamic lubrication and metallic inclusion theory on reciprocating motion, and provide the basis of designing variable clearance seal structure of hydraulic servo cylinder and developing clearance seal of hydraulic components.

我国重载高速伺服液压缸长期依赖进口，进口率达到90%以上，如何减小摩擦与提高频响是亟需解决的技术难题。在重载工况下现有的间隙密封技术液压缸抗偏载能力和动静态特性较差,磨损较严重。本项目以减小重载高速间隙密封伺服液压缸摩擦力为目标，结合弹性流体动压润滑（EHL）与金属夹杂理论，构造弹性形变可控的颗粒增强体铜基复合材料镀层，提出液压缸活塞密封间隙可变的思想，重点解决以下三个问题：（1）重载高速伺服液压缸往复运动非均质摩擦界面弹流润滑机理；（2）活塞几何形状与亚表层颗粒增强体耦合优化设计方法；（3）符合实际工况的间隙密封伺服液压缸弹流润滑试验系统。通过上述研究，从材料学角度解决偏载工况下重载高速伺服液压缸间隙密封摩擦特性及减磨的理论和技术问题，丰富间隙密封的发展内涵，拓展金属夹杂与弹流润滑理论在往复运动问题上的应用范围，为伺服液压缸变间隙密封结构设计及间隙密封液压元件设计提供依据。

我国重载高速伺服液压缸长期依赖进口，进口率达到90%以上，如何减小摩擦与提高频响是亟需解决的技术难题。在重载工况下现有的间隙密封技术液压缸抗偏载能力和动静态特性较差,磨损较严重。本项目以减小重载高速间隙密封伺服液压缸摩擦力为目标，结合弹性流体动压润滑（EHL）与金属夹杂理论，构造弹性形变可控的颗粒增强体铜基复合材料镀层，提出液压缸活塞密封间隙可变的思想，在以下几个方面进行了研究：1）基于弹流润滑的非均质摩擦界面多物理场耦合关系与增强体分布对界面几何形变的关系的研究。主要研究颗粒性质、粒径、埋藏深度和颗粒间距离对弹流润滑的影响，并且对颗粒结构参数进行了优化；2）颗粒脱黏对异质摩擦界面点接触弹流润滑影响的研究。主要建立了异质摩擦界面点接触弹流润滑模型；3）基于滑移/非滑移异质界面的动压润滑性能的优化研究。主要建立了一组离散式二次方程来描述滑移区和非滑移区拼接轨迹，并得到最优化轨迹；4）重载高速伺服液压缸摩擦界面弹流润滑特性的测试技术研究。主要提出了弹流润滑试验机测试方案。通过上述研究，从材料学角度解决偏载工况下重载高速伺服液压缸间隙密封摩擦特性及减磨的理论和技术问题，丰富间隙密封的发展内涵，拓展金属夹杂与弹流润滑理论在往复运动问题上的应用范围，为伺服液压缸变间隙密封结构设计及间隙密封液压元件设计提供依据。