轴向柱塞泵配流副液膜空化流动机理及润滑性能研究

Axial piston pump is an important high-end hydraulic product. Cavitation in the gap between cylinder block and valve plate causes a number of accidents, which needs to be investigated. A tribological pair composed of floating valve plate and fixed block will be investigated in the project. A mathematical model for the film cavitation and its corresponding numerical method will be developed to discover the mechanism of film cavitation under several given conditions. A simulation of hydraulic system based on axial piston pump will be performed to obtain the characteristics of hydraulic load on the distributing system. Based on the analysis of mechanics of the cylinder block-valve plate pair, a dynamic lubrication model considering film cavitation will be established, which is used to clarify the regularities of the impacts on lubrication performance caused by film cavitation. A test bench of model pump will be set up to develop a multi-approach method to measure the lubrication performance. The above model will also be verified experimentally. Not only does the application of the project help to improve the overall performance of the key tribological pairs in axial piston pump, but also it lays a foundation for the optimal design of the basic mechanical elements such as bearings and seals.

轴向柱塞泵是重要的高端液压元件。配流副间隙内的液膜空化流动问题可诱发多种故障状况，亟待开展深入的基础研究工作。本申请以浮动配流盘与固定缸体组成的配流副为研究对象，提出基于配流副特征的液膜空化流动数学模型及数值求解方法，研究特定条件下的液膜空化流动机理；建立轴向柱塞泵系统动态性能仿真模型，研究配流系统流体动态载荷特征分布规律；分析配流副的结构与力学特性，建立考虑液膜空化效应的配流副润滑动力学模型，揭示液膜空化对配流副润滑性能的影响规律；开发模型泵试验装置与试验平台，研究多手段协同测量配流副润滑性能参数的实验方法，完成实验验证。本项目的成功实施不仅有助于提升轴向柱塞泵关键摩擦副的综合性能，还对滑动轴承、机械密封等基础件的优化设计提供一定的依据。

本项目针对轴向柱塞泵配流副液膜空化流动问题，开展了数学建模、数值方法和实验测试等研究工作。通过考虑液压动态载荷与表面相对运动耦合产生的瞬态效应，提出了基于配流副特征的液膜空化流动数学模型及数值求解方法，掌握了配流系统动态载荷特征分布规律；建立了考虑液膜空化效应的配流副润滑动力学模型，开展了在不同工况条件下配流副润滑和密封性能分析对比；搭建配流副模型实验研究平台，研究了基于配流副表面接触特征的性能测试和分析方法。液膜空化程度与配流副转速和液压载荷大小呈正相关特点，这是源于两者对配流副间隙倾斜程度产生了较大的影响。随着配流盘腰形孔与缸体柱塞孔的依次接通，液膜空化面积发生着周期性的瞬变，造成了复杂的润滑状态，进而显著影响了配流副的宏观摩擦学性能（泄漏量、摩擦扭矩和轴向支撑）。以上工作为实现液压元件等基础件的性能优化设计提供了科学依据与理论支撑。