高压高速柱塞液压泵热力学机理及温度特性研究

This project is aimed at analyzing the inherent thermal problems of a high pressure and high rotational speed hydraulic piston pump. Since the mapping relationships of the structures, geometry dimensions, techniques, and the thermodynamic reliability and the thermodynamic mechanisms have not been revealed clearly now days, these type pumps are still rely on import seriously in our country. Researches will focus on the thermodynamic mechanisms and processes of the friction units including piston-cylinder pairs, slipper pairs and a valve plate pair. An integral thermodynamic model and a temperature field model of the fluid will be built up by considerably analyzing of heat transfer theorems, thermodynamics, elastohydrodynamics and tribology. Complicated heat transfer laws of the integral and parts of the pump will be obtained by analyses based on these models. Heat transfer processes between the friction units and structures, dynamic condition and its influence factors forming the thermal equilibrium, will be grasped. All these research will clarify the inherent relationship between the reliability and the thermodynamic processes of a piston pump. A dynamic thermal equilibrium model of oil film will be built up, the relationships between materials, structures and surface roughness of the friction units and the thermodynamic boundary of the film will be analyzed, and the relationships between operating parameters of the pump and the working dynamic boundary of the film will also be analyzed. These researches will yield out thermodynamic analyzing methods and steps. Build up the temperature spectrums of a piston pump under different pressures and rotational speeds, resolve the temperature relationships between the pump shell and internal parts, the reservior and ambient conditions. The basic theorem and method of evaluation and control of the pump temperature characteristics will be obtained by considering the thermodynamic processes of the pump. These will provide fundamental theorems and techniques for our basic elements research and development.

针对高速高压液压柱塞泵热力学机理以及结构、几何尺寸、工艺方法与热力学可靠性之间的映射关系尚不明确，关键基础件依赖进口的现状，研究液压泵包括柱塞副、滑靴副、配流副等重要摩擦副的热力学过程与机理，进行传热学、热动力学、流体动力学、弹性流体力学和摩擦学的深入分析，建立柱塞泵整体热力学模型以及流体温度场模型，取得整体及部件复杂传热过程的规律，掌握液压泵偶件传热过程和热平衡点形成的动态条件及其影响因素，阐明柱塞泵热力学过程与可靠性的内在关系。建立摩擦副油膜动态热平衡模型，分析摩擦副材料、结构、表面粗糙度与油膜热力学边界的关系，分析柱塞泵工作参数与摩擦副工作动力学边界的关系；取得液压泵热设计方法和措施。建立不同压力和转速下柱塞泵的温度特性谱，解析泵壳体、泵部件、油箱及环境的温度关系，取得考虑热力学过程的柱塞泵特性评价和控制的基本理论和方法，为我国核心基础件研究与开发提供基础理论和技术。

柱塞液压泵是航空航天、工程机械等领域机械装备液压传动系统的核心动力元件。系统大功率、节能的发展需求，使得柱塞液压泵朝着高压、高速、大容量、低噪声和长寿命方趋势发展。要实现这些目标的关键之一在于合理设计柱塞液压泵中各种类型的摩擦副，使之能形成适当的油膜，提高效率、降低温升、减轻磨损，提高寿命与可靠性。因此，本项目针对柱塞液压泵的热力学机理，利用传热学、热动力学、流体力学、弹性流体力学及摩擦学等相关理论，对柱塞液压泵的发热机理、摩擦副油膜的形成与发展机制、摩擦副与油膜间的热流固耦合机理、摩擦副油膜特征和温度特性，以及工况参数、材料性能、结构尺寸及环境因素对其的影响规律进行了深入解析。. 项目实施过程中，以工程机械A4V型泵和某型航空柱塞液压泵为对象，对其柱塞副、滑靴副和配流副和泵整体热特性开展了理论分析、仿真计算和试验研究，取得的主要研究成果如下：.1）建立了轴向柱塞泵摩擦副热流体动力润滑模型，揭示了摩擦副油膜动力学特征，并以此取得了摩擦副润滑机理与接触表面磨损失效形式的关联性。.2）利用摩擦副与油膜的传热特征，引入摩擦副的受热变形，结合能量守恒定律，建立了摩擦副油膜热力学参数化模型，解析了多物理场耦合下摩擦副热力耦合变形及摩擦磨损性能，为轴向柱塞泵摩擦副间隙优化提供理论支持； .3）通过对不同结构形状、工作参数条件下摩擦副油膜的油膜厚度、泄漏流量、摩擦力矩的耦合关系进行解析，阐明了轴向柱塞泵摩擦副油膜的润滑承载特性与工况条件、结构参数的映射关系。.4）利用热流体控制体和流固耦合传热原理，建立了泵内部发热与壳体热特性及壳体回油温度量化计算模型，为泵体强制散热设计提供理论依据。.5）针对机载泵源系统压力与负载压力的匹配问题，建立了负载敏感控制泵的温度计算模型，并对现有恒压力控制泵源系统与负载敏感变压力控制系统的温度特性进行了仿真分析，可为负载敏感泵与系统匹配设计提供参考。