微型超高压单柱塞泵密封和气穴特性研究

发布时间：2018-11-26 10:59

【摘要】：液压泵作为液压系统的动力源,其泄漏约占液压系统总泄漏量的7.5%,液压泵的泄漏不仅影响泵的容积效率、降低泵的工作寿命、造成资源的浪费、甚至还造成环境污染,因此液压泵的防泄漏问题尤为重要。气穴现象是诱发液压元件噪声最普遍、最主要的原因之一,它会使液压泵的效率降低、损坏零件、缩短液压元件和管道的寿命、造成流量和压力的脉动。因此,为了设计低泄漏、低气穴的液压泵,研究液压泵的密封和气穴问题非常重要。论文的主要内容如下：第1章,阐述了本课题研究的目的和意义；分别概述了柱塞泵的密封和气穴问题的研究现状；对流固耦合技术和多相流理论及其在课题中的应用也分别做了简单的概括。第2章,对单柱塞泵往复密封的流固耦合数值模拟所涉及到的液压柱塞往复密封理论以及气穴流场数值模拟中所涉及到的气泡动力学理论做了简要的介绍。第3章,对单柱塞泵往复密封这种典型的流固耦合问题,运用ANSYS Workbench和CFX软件进行联合仿真,得出不同压力下密封间隙的压力分布、泄漏量、密封间隙的径向位移分布等结论。在实验方面,采用了无0型密封圈和有0型密封圈两套实验装置来对比测试柱塞腔的油液泄漏量大小。将仿真和实验结果进行比较,模拟得到的柱塞腔的泄漏量与实验得到的泄漏量比较吻合,表明该流固耦合的仿真模型是有效的。第4章,针对单柱塞泵工作容腔的气穴现象,运用Fluent软件对柱塞泵工作容腔的气穴流场进行了数值模拟,采用了非平衡壁面函数的K-ε模型和带有空化作用的多相流混合模型,得出了不同阀口开度和入口速度下柱塞泵工作容腔的气穴流场的分布规律。在实验方面,采用了不带补油泵和带补油泵两套实验装置来对比测试柱塞泵工作容腔的真空度大小。将仿真和实验结果进行比较,模拟得到的柱塞泵工作容腔的真空度和实验得到的真空度比较吻合,表明非平衡壁面函数的K-ε模型和带有空化作用的多相流混合模型能够有效地预测柱塞泵工作容腔气穴流场的分布规律。第5章,对本论文的研究工作和成果进行了总结,展望了下一步的研究工作。
[Abstract]:Hydraulic pump as the power source of hydraulic system, its leakage accounts for about 7.5% of the total leakage of hydraulic system. The leakage of hydraulic pump not only affects the pump's volumetric efficiency, reduces the pump's working life, causes the waste of resources, but also causes environmental pollution. Therefore, the hydraulic pump leakage prevention problem is particularly important. The cavitation phenomenon is one of the most common and main reasons that induce the noise of hydraulic components. It can reduce the efficiency of hydraulic pump, damage parts, shorten the life of hydraulic components and pipes, and cause flow and pressure pulsation. Therefore, in order to design the hydraulic pump with low leakage and low cavitation, it is very important to study the sealing and cavitation of hydraulic pump. The main contents of this paper are as follows: in Chapter 1, the purpose and significance of this research are described, and the research status of sealing and cavitation of piston pump is summarized respectively. The convection-solid coupling technique and the theory of multiphase flow and their applications in the subject are also briefly summarized. In chapter 2, the theory of hydraulic plunger reciprocating seal and the theory of bubble dynamics involved in numerical simulation of single piston pump reciprocating seal are briefly introduced. In chapter 3, the typical fluid-solid coupling problem of reciprocating seal of single piston pump is simulated by ANSYS Workbench and CFX software, and the results of pressure distribution, leakage amount and radial displacement distribution of seal clearance under different pressure are obtained. In the aspect of experiment, the oil leakage of plunger cavity is measured by two sets of experimental devices: no 0 seal ring and 0 type seal ring. By comparing the simulation results with the experimental results, the leakage of the simulated plunger cavity is in good agreement with the experimental leakage, which shows that the simulation model of fluid-solid coupling is effective. In chapter 4, according to the cavitation phenomenon of single piston pump working cavity, the cavitation flow field of piston pump working cavity is numerically simulated by Fluent software. The K- 蔚 model of non-equilibrium wall function and the mixed model of multiphase flow with cavitation are adopted. The distribution of cavitation flow field in piston pump working cavity with different opening and inlet velocity is obtained. In the aspect of experiment, the vacuum degree of the piston pump working cavity is compared with that of the oil pump without oil supply and the pump with oil supply. By comparing the simulation results with the experimental results, the vacuum degree of the piston pump working cavity obtained by the simulation is in good agreement with the experimental vacuum degree. It is shown that the K- 蔚 model of non-equilibrium wall function and the mixed model of multiphase flow with cavitation can effectively predict the distribution of cavitation flow field in piston pump. Chapter 5 summarizes the research work and results of this paper, and looks forward to the next research work.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH322

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