水液压泵柱塞副密封间隙的自动补偿机理研究

Due to the urgent need for high performance water hydraulic pump in each department of our national economy, especially the field of ocean exploitation, and the technical bottleneck in the seal and wear of piston cylinder interface within water hydraulic pump, this research puts forward a technical scheme of automatic compensation for piston interface gap. Centering on the law of piston bush deformation under multi-field coupling influence, and the stable control of the piston interface gap, the working mechanism and experimental research on the automatic compensation of piston pair seal clearance will be conducted systematically. Firstly, this research will emphatically reveal the deformation characteristics of the piston bush under annular fluid pressure. Then the multi-field coupling influence on the lubrication characteristics and energy dissipation of the piston pair shall be illustrated. In order to decrease the leakage and energy dissipation in the piston pair, the characteristic parameters optimization of the piston pair will be studied. Finally, the prototype will be developed to verify the theory in this research. Afterwards, this research will obtain the mapping principle between the piston bush deformation and the lubrication characteristics and energy dissipation of the piston pair, as well as the balance design criterion consideration to annular clearance leakage and friction loss in the piston pair. Then the optimal allocation of the piston pair parameters will be provided, to achieve the efficient seal and automatic compensation of the wear clearance of the piston pair within water hydraulic pump. The original achievements of the prototype structure and theoretical method will be hopefully gained, and the design theory and technical level of the water hydraulic pump of our country will be increased to a new level.

以我国国民经济各部门尤其是海洋开发领域对高性能水液压泵的迫切需求为牵引，针对目前水液压泵柱塞副在密封、磨损方面存在的技术瓶颈，本项目提出一种柱塞副密封间隙自动补偿方案。围绕所涉及的多场耦合作用下柱塞套的变形规律、柱塞副密封间隙稳定控制的关键科学问题，系统地开展柱塞副密封间隙自动补偿的工作机理研究。重点揭示环形流体压力作用下柱塞套的变形特性，阐明多场耦合作用对柱塞副润滑特性和能量损耗的作用机制，研究以降低柱塞副泄漏和摩擦损耗为目标的柱塞副特性参数优化方法，并开展样机研制和试验验证。获取多场耦合作用下柱塞套变形和柱塞副润滑特性、能量损耗的映射规律，建立兼顾柱塞副环形缝隙泄漏和摩擦损耗的平衡设计准则，对柱塞副特性参数进行优化配置，实现水液压泵柱塞副的高效密封和磨损间隙的自动补偿。本项目有望在理论方法和样机结构上取得创新成果，提升我国水液压泵的设计理论和技术水平。

为实现水液压泵柱塞副的高效密封并自动补偿其磨损后的配合间隙，本项目提出了一种柱塞副密封间隙自动补偿结构。通过流固耦合仿真技术研究了不同柱塞套厚度和环形槽宽度下柱塞套在内侧环形流体和外侧环形缝隙流体耦合作用下的变形特性。仿真结果表明，在相同的工作压力、流体域边界条件下，当环形槽宽不变时，随着工程塑料PEEK材质的柱塞套厚度的增加，柱塞套变形量逐渐减小；当柱塞套厚度不变时，柱塞套变形量随着环形槽宽的增加而逐渐增大。建立了考虑弹性流体动力学行为、粘温效应和深海环境的水液压泵柱塞副参数化弹流润滑模型。讨论了不同工况下柱塞套的变形、水膜的承载机理和能量损失特性。结果表明，在水膜和深海压力的作用下，PEEK柱塞套的变形量为微米级，增加了柱塞副的泄漏量和粘滞摩擦功率损失。在深海环境中，弹流动压润滑计算的泄漏量和粘滞摩擦功率损失总是大于动压润滑模型计算的泄漏量和粘滞摩擦功率损失，并且随着工作压力、主轴转速、间隙尺寸、海洋深度、海水温度和活塞套厚度的增加而增大。随着海水温度的升高，粘性摩擦损失减小。得到了动压润滑和弹流动压润滑条件下的水膜承载机理、柱塞套的变形特性和柱塞副的能量损失特性。比较分析了工作压力、主轴转速、柱塞副间隙尺寸、海水温度、海洋深度和柱塞套厚度对柱塞副能量损失特性的影响规律。从而建立了一套流固耦合作用下柱塞副动压水膜理论模型，揭示出柱塞副间隙自动补偿机理和结构优化设计方法，并形成了初步的理论架构。完成了柱塞副流固耦合特性研究，实现了关键系统参数的优化，并据此研制出了水液压泵密封间隙自动补偿柱塞副原理样机。搭建了柱塞副间隙水膜厚度检测试验系统，完成了柱塞副间隙自动补偿性能试验，试验数据和仿真结果基本一致。本项目研究成果丰富了水液压泵柱塞副润滑和密封理论，并在实际水液压泵中取得了应用，具有重要的理论意义和工程价值。