球塞式内曲线液压马达失效分析与径向力不平衡问题

发布时间：2019-07-06 20:17

【摘要】：低速大扭矩液压马达因为功率密度大、低速稳定性好、启动转矩大等优点普遍应用在各类行走机械的液压系统上。球塞式内曲线液压马达更以其体积小、结构简单、价格低廉等优势在许多工程机械中得到应用。但在使用过程中也发现了诸多问题,主要是马达寿命短、使用一段时间后效率急剧下降等。本文针对球塞式液压马达在使用过程中出现柱塞变形和磨损严重,导轨出现点蚀和断裂问题,对球塞式液压马达进行了受力分析和失效分析;在内曲线液压马达的设计计算中,一般认为回油背压为恒定值,本文通过CFD流场解析和力学分析,发现各柱塞回油背压存在较大差别,并导致内曲线液压马达转子径向力不平衡;在提出内曲线液压马达径向力不平衡问题的同时,指出了不平衡径向力与导轨断裂现象的关系。本文的主要内容: 第1章,阐述了本课题研究的目的、意义及本课题的研究背景;概述了内曲线液压马达的国内外研究及发展概况;概括了本论文的主要研究内容。第2章,阐述了球塞式内曲线液压马达的结构及工作原理;运用PROE软件对内曲线液压马达导轨进行参数化设计;在内曲线液压马达基本理论的基础上,运用MATLAB软件对球塞式内曲线液压马达的运动学和力学特性进行解析,为球塞式内曲线液压马达进一步研究奠定了基础。第3章,针对球塞式液压马达在使用过程中出现柱塞变形和磨损严重,导轨出现点蚀和断裂问题,对球塞式液压马达进行了失效分析;对液压马达工况进行了实验测试,实车测试表明马达运转过程中系统压力波动剧烈,提出了通过提高安全阀动态性能或加设蓄能器以减小系统压力波动,从而解决因压力波动引起导轨失效的问题。第4章,分析了球塞式液压马达转子工作过程;通过CFD流场解析和力学分析,发现各柱塞回油背压存在较大差别,并导致内曲线液压马达转子径向力不平衡;在提出内曲线液压马达径向力不平衡问题的同时,分析了不平衡径向力与导轨断裂现象的关系;指出内曲线液压马达的转子与各柱塞所形成腔体内回油背压变化会产生附加转矩脉动;指出转子在径向不平衡力的作用下与配流轴所形成的间隙之间会发生周期性涡动现象。
文内图片：

图片说明：内曲线导轨CAD模型
[Abstract]:Low speed and high torque hydraulic motor is widely used in hydraulic system of all kinds of walking machinery because of its high power density, good low speed stability and large starting torque. Ball plug internal curve hydraulic motor has been applied in many construction machinery because of its small volume, simple structure and low price. However, many problems have also been found in the process of use, mainly because of the short life of the motor and the sharp decline of efficiency after a period of use. In view of the serious deformation and wear of plunger and the pitting corrosion and fracture of guide rail in the course of using ball plug hydraulic motor, the force analysis and failure analysis of ball plug hydraulic motor are carried out in this paper. In the design and calculation of inner curve hydraulic motor, it is generally considered that the back pressure of return oil is a constant value. Through CFD flow field analysis and mechanical analysis, it is found that there are great differences in the back pressure of plunger return oil, which leads to the imbalance of radial force of rotor of inner curve hydraulic motor, and the relationship between unbalanced radial force and fracture phenomenon of guideway is pointed out while the imbalance of radial force of inner curve hydraulic motor is put forward. The main contents of this paper are as follows: in chapter 1, the purpose, significance and research background of this subject are described, the research and development of internal curve hydraulic motor at home and abroad are summarized, and the main research contents of this paper are summarized. In chapter 2, the structure and working principle of ball plug internal curve hydraulic motor are described; the parametric design of inner curve hydraulic motor guide rail is carried out by using PROE software; on the basis of the basic theory of inner curve hydraulic motor, the kinematic and mechanical characteristics of ball plug internal curve hydraulic motor are analyzed by using MATLAB software, which lays a foundation for the further study of ball plug internal curve hydraulic motor. In chapter 3, the failure analysis of the ball plug hydraulic motor is carried out in view of the serious deformation and wear of the plunger and the pitting corrosion and fracture of the guideway during the use of the ball plug hydraulic motor. The experimental test of hydraulic motor is carried out. The real vehicle test shows that the pressure of the system fluctuates violently during the operation of the motor. It is proposed to reduce the pressure fluctuation of the system by improving the dynamic performance of the safety valve or adding an accumulator, so as to solve the problem of guideway failure caused by the pressure fluctuation. In chapter 4, the working process of ball plug hydraulic motor rotor is analyzed, through CFD flow field analysis and mechanical analysis, it is found that there are great differences in the back pressure of each plunger back oil, which leads to the imbalance of radial force of inner curve hydraulic motor rotor, and the relationship between unbalanced radial force and guide rail fracture phenomenon is analyzed while the imbalance of radial force of inner curve hydraulic motor is put forward. It is pointed out that the change of return back pressure between the rotor of the inner curve hydraulic motor and each plunger will produce additional torque pulsation, and it is pointed out that the periodic vortex phenomenon will occur between the rotor and the gap formed by the distribution shaft under the action of the radial imbalance force.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137.51

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