高水基径向柱塞泵往复密封摩擦副润滑与密封性能研究.pdf

万方数据 万方数据 学位论文答辩信息表 论文题目 高水基径向柱塞泵往复密封摩擦副润滑与密封性能 研究 课题来源* 省科技厅项目液压支架用高水基高速自润滑径向 柱塞泵研制（201903D121050） 论文答辩日期 2020 年 5 月 29 日 答辩秘书 张旭飞 学位论文答辩委员会成员 姓名 职称 博导 工作单位 答辩委员 会主席 徐格宁 教授 是 太原科技大学 答辩委员1 李运华 教授 是 北京航空航天大学 答辩委员2 吕明 教授 是 太原理工大学 答辩委员3 权龙 教授 是 太原理工大学 答辩委员4 王铁 教授 是 太原理工大学 *课题来源可填国家重点研发计划项目、国家自然科学基金项目、 国家社科基金项目、教育部人文社科项目、国家其他部委项目、省科 技厅项目、省教育厅项目、企事业单位委托项目、其他 摘要 I 摘 要 高水基柱塞泵是煤矿综采装备的动力核心元件，主要为液压支架提供 高压流体，被誉为综采装备的“心脏”。柱塞副作为柱塞泵的关键摩擦副， 其密封组件不仅需要具备防腐耐磨特性，还要实现良好的润滑与密封等功 能，其摩擦、磨损、润滑与密封性能直接决定着柱塞泵的容积效率与使用 寿命，对综采装备液压传动系统的可靠性、安全性起着重要作用。受粘度 低、腐蚀性强等物化性能影响，高水基柱塞副摩擦磨损、泄漏和腐蚀等问 题更为突出。因此，研究密封结构的摩擦与泄漏特性，揭示往复密封运动 过程的润滑与密封机理，对提高柱塞泵、尤其是高水基柱塞泵的往复密封 可靠性具有十分重要的理论与应用价值。本论文以高水基柱塞泵为研究对 象，采用理论计算、数值仿真与实验测试相结合的方法，对往复高水基柱 塞副的润滑与密封性能进行研究，论文主要研究工作如下 基于 IHL 逆解法，结合表面粗糙度接触理论，建立了既考虑流体粘性 又包含粗糙度接触的往复密封混合润滑模型。采用 ANSYS 有限元仿真软 件对密封结构的形变与接触行为进行分析，得到密封元件的固体力学和接 触力学特征；通过 MATLAB 程序语言对泄漏量与摩擦力等参数进行求解， 得到了柱塞副往复密封的摩擦学特性。该模型利用 IHL 方法把偏微分方程 转化为一元三次代数方程计算油膜流体压力的特点，有效避免了求解雷诺 方程迭代计算耗时多、数值解收敛困难等问题。此外，通过对比往复密封 摩擦力实验结果，相比传统 IHL 纯油膜剪切方法研究往复密封摩擦性能， 该模型在油膜粘性摩擦力的基础上引入粗糙度接触摩擦力，具有更高的精 度和良好的鲁棒性。 为进一步考虑密封区流体与密封元件的流-固耦合作用，基于弹性半空 间变形理论，通过在雷诺方程中引入平均流动因子和空化因子，建立了综 合考虑表面粗糙度与流体空化效应的往复密封混合弹流润滑模型。分别采 用有限体积法和基于一阶拉格朗日形函数的有限元素法对雷诺方程和弹性 变形方程进行迭代求解，模拟流体压力与密封元件弹性变形的流-固耦合过 程，得到密封区的油膜流体压力、油膜厚度与流场分布等特征，在此基础 上计算往复密封的摩擦力与泄漏量等密封性能参数。该方法有效避免了传 统混合弹流润滑模型建模过程中计算影响系数矩阵效率不高的问题。进一 步通过对比摩擦力的计算值与实验值对构建的润滑模型进行验证，计算摩 太原理工大学博士学位论文 II 擦力与实验结果吻合较好，验证了该模型的合理性与可行性。 利用上述高水基柱塞副的往复密封数值计算模型，定量分析了密封元 件安装预压缩量、流体密封压力、柱塞运动速度和密封元件表面粗糙度等 多种因素对高水基柱塞泵密封组件往复密封与润滑性能的影响。分析讨论 了往复摩擦力、泄漏量、密封区的油膜厚度、油膜流体压力、粗糙度接触 压力和流体速度场的分布规律，探明了密封结构及相关工况参数对高水基 柱塞泵往复密封性能的影响机制， 揭示了高水基柱塞副的润滑与密封机理。 结果表明，提高柱塞速度可增强流体的动压效应从而使得摩擦力减小，而 增大密封圈表面粗糙度可显著减弱流体的动压效应。当柱塞运动速度较小 时，密封圈表面粗糙度对往复密封摩擦力的影响很小；当柱塞运动速度较 大时，往复密封摩擦力随密封表面粗糙度的减小明显减小。此外，当密封 表面较光滑时，提高柱塞速度可显著降低往复密封摩擦力；当密封表面粗 糙度较大时，往复密封摩擦力随柱塞速度的增大无明显变化。通过分析密 封区 Poiseuille-Couette 流动各组分的流量演变规律，给出了高水基柱塞副 在往复行程无泄漏的柱塞速度和密封粗糙度的临界值。相比传统润滑油介 质，高水基介质柱塞副在往复行程实现零泄漏的临界粗糙度远小于润滑油 介质对应的临界粗糙度。研究结果对提高柱塞副往复密封可靠性，实现高 水基柱塞泵的高速化具有重要意义。 关键词柱塞泵；高水基柱塞副；混合润滑；摩擦力；泄漏量 ABSTRACT III ABSTRACT The water-based hydraulic piston pump generally serves as the core power source and known as the heart element of fully mechanized coal mining equipment. It mainly provides high fluid pressure to the hydraulic roof supports. As the key friction pair of the piston pump, the assembled seal of the piston pair not only requires great anti-corrosion and wear resistance capabilities, but also achieves effective lubrication and sealing functions. It plays a significant role in the reliability and safety of the hydraulic transmission system of comprehensive mining equipment for the reason that the friction, wear, lubrication and sealing perance of assembled piston seals directly determine the volumetric efficiency and service life of the piston pump. The problems of friction, wear, leakage and corrosion of the high water-based piston pairs are more prominent due to its physical and chemical properties, such as low viscosity and strong corrosion. Therefore, attempts to explore the friction and leakage characteristics of reciprocating seals, and further reveal the lubrication and sealing mechanisms are of great importance for the theory and application to improve of the reliability of piston pump, especially for the reliability of high water-based pump. In this thesis, a combination of theoretical calculation, numerical simulation, and experiment test was applied to investigate the lubrication and sealing perance of the high water-based piston pair. The main research contents are introduced as follows An innovative partial lubrication numerical model of the reciprocating seal was established which connects the pure film stress IHL theory and the asperity contact model. The model takes the fluid viscosity and asperity contact into account. The finite element software ANSYS was used to simulate the solid deation and contact mechanics of sealing element and the MATLAB program code was applied to calculate the tribological behaviors in terms of the reciprocating friction force and leakage. The proposed model effectively overcomes the defect of prohibitively large computation time and difficulty in converging numerical solutions based on fact that the IHL theory converts the partial differential equations into one-dimensional cubic algebraic equations to 太原理工大学博士学位论文 IV calculate the fluid film pressure. In addition, the advantages of this approach over the conventional IHL numerical model lie with that it considers not only the fluid viscosity friction, but also includes the asperity contact friction. Compared with reciprocating test data and the pure film stress IHL theory, the present model is more accurate, robust and effective to describe the reciprocating sealing perance. To further consider the fluid-structure coupling interaction between the fluid and sealing element, an effective elastohydrodynamic partial lubrication model of reciprocating seal was proposed based on the elastic half-space theory. The flow factors and cavitation factors were introduced into the Reynolds equation to represent the effect of the surface roughness and fluid cavitation behaviors. The finite volume and finite elements based on the first order Lagrange shape function were used to interactively solve the modified Reynolds equation and elastic equation respectively, which simulates the fluid-structure process between the fluid pressure and the elastic deation. The reciprocating sealing perance in terms of friction and leakage were determined based on the computed dynamic fluid film pressure, film thickness and fluid velocity field. The present model overcomes the low efficiency in calculating the influence coefficient matrix in the modeling process of the traditional EHL partial lubrication model. The accuracy and reliability of the EHL partial lubrication model were validated with the test data and good agreements were observed. According to the proposed partial lubrication models of the high water-based piston pair, the corresponding effects of interference fit of sealing element, fluid sealed pressure, rod velocity and surface roughness parameters of sealing element on the lubrication and sealing perance were conducted. The characteristics of the friction force, leakage, film thickness, fluid film pressure, asperity contact pressure and fluid velocity field were analyzed and discussed. The influence mechanism of the seal structure as well as the working related parameters on the sealing perance of the high water-based piston pump were clarified, and the lubrication and sealing mechanism of high water-based piston pair were revealed. The results show that an increase of the rod velocity could enhance the fluid dynamic effect accompanied with the reduced friction force, while the surface roughness could considerably weaken the fluid dynamic ABSTRACT V effect. It should be mentioned that the surface roughness have little effect on the friction force when the rod velocity is small. However, the friction force is significantly reduced as the surface roughness decreases for the situations that the rod velocity experiences a high number. In addition, when the seal surface is relatively smooth, an increase of the rod velocity could considerably reduces the frciton force. The friction force shows little difference as the rod velocity increases for a larger amount of the surface roughness of seal. The evolution analysis of the fluid transport between the Poiseuille-Couette fluid components at the sealing interface were pered to get the critical RMS roughness of the sealing friction pairs was achieved for zero net leakage during a complete stroke of the high water-based piston pump. Compared with the conventional lubricating oil, the critical roughness of the zero net leakage during a complete stroke under high water-based fluid is much smaller than that corresponding to the oil lubricant. The results are of great significance for improving the reliability of the reciprocating seal for the piston pair and realizing the high speed of the high water-based piston pump. Key Words Piston Pump; High Water-Based Piston Pairs; Partial Lubrication; Friction Force; Leakage 目录 VII 目 录 摘 要 ......................................................................................................................................... I ABSTRACT ............................................................................................................................. III 目 录 ...................................................................................................................................... VII 附图清单 .................................................................................................................................. XI 附表清单 ............................................................................................................................... XXI 符号清单 ............................................................................................................................ XXIII 第 1 章 绪论 .............................................................................................................................. 1 1.1 选题背景及意义 .......................................................................................................... 1 1.2 国内外研究现状 .......................................................................................................... 3 1.2.1 往复密封结构有限元分析 ................................................................................ 3 1.2.2 往复密封润滑理论 ............................................................................................ 6 1.2.3 往复密封实验测试 ............................................................................................ 8 1.3 现有研究的不足 ........................................................................................................ 11 1.4 主要研究内容与技术路线 ........................................................................................ 13 1.4.1 主要研究内容 .................................................................................................. 13 1.4.2 技术路线 .......................................................................................................... 15 第 2 章 基于 IHL 理论的混合润滑模型 ............................................................................... 17 2.1 引言 ............................................................................................................................ 17 2.2 基于 IHL 的混合润滑模型 ....................................................................................... 18 2.2.1 模型假设 .......................................................................................................... 20 2.2.2 密封区润滑油膜的流体力学 .......................................................................... 20 2.2.3 密封表面粗糙度接触模型 .............................................................................. 24 2.2.4 摩擦力与泄漏模型 .......................................................................................... 27 2.2.5 表面形貌参数 .................................................................................................. 30 2.2.6 数值计算流程 .................................................................................................. 35 2.3 模型有效性验证 ........................................................................................................ 35 2.4 小结 ............................................................................................................................ 38 第 3 章 基于弹性半空间的混合弹流润滑模型 .................................................................... 39 太原理工大学博士学位论文 VIII 3.1 引言 ............................................................................................................................ 39 3.2 控制方程 .................................................................................................................... 40 3.2.1 考虑表面粗糙度形貌与空化效应的平均雷诺方程 ...................................... 40 3.2.2 粗糙度接触方程 .............................................................................................. 44 3.2.3 油膜厚度方程 .................................................................................................. 45 3.2.4 密封元件微弹性变形方程 .............................................................................. 45 3.2.5 往复密封摩擦力与泄漏量 .............................................................................. 47 3.2.6 边界条件 .......................................................................................................... 48 3.3 数值计算方法 ............................................................................................................ 48 3.3.1 空间计算区域的离散化 .................................................................................. 48 3.3.2 控制方程的离散 .............................................................................................. 50 3.3.3 TDMA 算法 ...................................................................................................... 57 3.3.4 数值计算流程 .................................................................................................. 58 3.4 模型有效性验证 ........................................................................................................ 60 3.5 小结 ............................................................................................................................ 61 第 4 章 高水基柱塞副往复密封的摩擦与泄漏特性 ............................................................ 63 4.1 引言 ............................................................................................................................ 63 4.2 密封结构有限元模型 ................................................................................................ 63 4.2.1 几何模型 .......................................................................................................... 64 4.2.2 单元类型与接触算法 ...................................................................................... 65 4.2.3 材料属性 .......................................................................................................... 65 4.2.4 边界条件 .......................................................................................................... 67 4.2.5 网格收敛性验证 .............................................................................................. 68 4.3 柱塞副静态变形与接触力学分析 ............................................................................ 69 4.3.1 静态密封性能关键参数 .................................................................................. 69 4.3.2 安装过盈量对静密封性能的影响 .................................................................. 70 4.3.3 密封压力对静密封性能的影响 ...................................................................... 72 4.4 基于 IHL 的斯特封柱塞副混合摩擦与泄漏特性 ................................................... 75 4.4.1 密封压力与往复速度的影响 .......................................................................... 75 4.4.2 过盈量与往复速度的影响 .............................................................................. 77 4.4.3 表