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Experimental and Analytical Investigation of Floating Valve Plate Motion in an Axial Piston Pump 总被引:1,自引:0,他引:1
The purpose of this investigation was to experimentally measure the motion of the floating valve plate in an axial piston pump under various operating conditions and to develop a model to determine how the floating valve plate motion affected the lubricating pressures between the valve plate and cylinder block. In order to achieve the objectives, a hydraulic circuit was designed and developed to incorporate and operate a floating valve plate axial piston pump. The hydraulic circuit integrating the axial piston pump (axial piston pump apparatus, APPA) consists of a series of valves, pressure sensors, a charge pump, flow meters, temperature sensors, a heat exchanger, and proximity probes. The floating valve plate axial piston pump housing was modified to incorporate three proximity probes to measure the valve plate position and motion relative to the cylinder block, thus allowing for determination of the film thickness within this contact. The results illustrate that as the pump starts up the valve plate experiences vibrations and begins to lift relative to the cylinder block. Then as the pump reaches steady-state operation the valve plate achieves a fixed position and tilt. The results also demonstrate that under steady-state operation, the valve plate vibrates and this vibration correlates well with the speed and the number of pistons in the pump. The measured film thickness results were then used in a lubrication model to determine the pressures generated between the floating valve plate and the cylinder block. The analytical results highlight how the motion of the valve plate directly correlates to the pressure pulsations seen in the lubricating gap. 相似文献
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The design of an axial piston pump for electro-hydrostatic transmission systems requires accurate information where and how
much the internal friction and flow losses are produced. This study is particularly focused on the friction losses of a bent-axis
type hydraulic piston pump, aiming at finding out which design factors influence its torque efficiency most significantly.
To this end, the friction coefficients of the pump parts such as piston heads, spherical joints, shaft bearings, and valve
plate were experimentally identified by a specially constructed tribometer. Applying the experimental data to the equations
of motion for pistons as well as to the theoretical friction models for the pump parts, the friction torques produced by them
were computed. The accuracy of the computed results was confirmed by the comparison with the practical input torque of the
pump. In this paper, it is shown that the viscous friction forces on the valve plate and input shaft bearing are the primary
source of the friction losses of the bent-axis type pump, while the friction forces and moments on the piston are of little
significance. 相似文献
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当斜盘轴向柱塞泵处于高压工况时,其配流盘会产生翘曲变形。基于弹性流体动力润滑理论,建立斜盘轴向柱塞泵配流副流固耦合模型,求解配流副润滑控制方程,分析了斜盘轴向柱塞泵缸体转速、缸体倾角、液压油黏度、配流副油膜厚度、配流副密封带宽度等工况与结构参数对其配流盘发生翘曲变形的影响。研究显示:斜盘轴向柱塞泵配流盘变形云图以腰形槽中心连线为轴线呈现一定的对称分布;配流盘高压侧外密封带区域变形最大,配流盘低压侧外密封带区域变形最小;在相同工况下,配流盘的材料与结构影响配流副油膜厚度与形状。 相似文献
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Current researches mainly focus on the investigations of the valve plate utilizing pressure relief grooves. However,air?release and cavitation can occur near the grooves. The valve plate utilizing damping holes show excellent perfor?mance in avoiding air?release and cavitation. This study aims to reduce the noise emitted from an axial piston pump using a novel valve plate utilizing damping holes. A dynamic pump model is developed,in which the fluid properties are carefully modeled to capture the phenomena of air release and cavitation. The causes of di erent noise sources are investigated using the model. A comprehensive parametric analysis is conducted to enhance the understanding of the e ects of the valve plate parameters on the noise sources. A multi?objective genetic algorithm optimization method is proposed to optimize the parameters of valve plate. The amplitudes of the swash plate moment and flow rates in the inlet and outlet ports are defined as the objective functions. The pressure overshoot and undershoot in the piston chamber are limited by properly constraining the highest and lowest pressure values. A comparison of the various noise sources between the original and optimized designs over a wide range of pressure levels shows that the noise sources are reduced at high pressures. The results of the sound pressure level measurements show that the optimized valve plate reduces the noise level by 1.6 d B(A) at the rated working condition. The proposed method is e ective in reducing the noise of axial piston pumps and contributes to the development of quieter axial piston machines. 相似文献
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A study on the pressure ripple characteristics in a bent-axis type oil hydraulic piston pump 总被引:1,自引:0,他引:1
To improve the performance of a bent-axis type axial piston pump driven by tapered pistons, it is necessary to know the pressure ripple characteristics. The purpose of this paper is to understand the effect on the pressure ripple characteristics, and to predict by comparing experimental and theoretical analysis results. The simulation model of a bent-axis type axial piston pump is developed in the AMESim environment using the geometrical dimension, and the driving mechanism of the piston pump, such as the stroke of pump, the velocity of piston, the instantaneous volumetric flow, the overlap area of valve plate opening to cylinder bore, the angle of notch, and so on. The results show that theoretical analysis results of the bent-axis type axial piston pump by using the AMESim approximate the pressure ripple characteristic of the test pump, and through this, simulations can be obtained that predict the performance characteristics of a bentaxis type axial piston pump. 相似文献
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为了进行供油压力高、输出流量大的轴向柱塞泵配流副、滑靴副等关键摩擦副润滑膜性能试验,基于试验供油油路与加载油路分离原则,研制了轴向柱塞泵摩擦副润滑性能试验系统。论述了轴向柱塞泵摩擦副润滑特性研究的必要性及目前试验研究存在的主要问题,根据润滑理论模型分析了试验研究的主要内容,针对其难点提出了基于精密位置反馈的新型电液控制润滑膜动态试验系统组成、特点及关键技术等。通过在研制的试验系统上进行实际的油膜平衡、密封带多点膜厚实测及泄漏流量与膜厚等试验的数据分析表明,该试验系统稳定、可靠,能够完成预期设计的试验对系统的要求,亦可开展相关摩擦副润滑特性试验研究。 相似文献
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为了研究双排式轴向柱塞泵的流量脉动特性,对双排式轴向柱塞泵柱塞的排列方式进行了分类,列写流量方程并计算不同错位角下柱塞泵的流量不均匀系数,分析柱塞排列方式和错位角的变化对双排式轴向柱塞泵流量脉动特性的影响。研究发现内外排柱塞数相同且同为奇数时,改变错位角得到的最小流量不均匀系数小于同等柱塞数的单排式轴向柱塞泵的流量不均匀系数,双排式轴向柱塞泵的流量脉动特性得到显著改善。同时还发现内外排柱塞数均为5,且错位角为π/10的双排式轴向柱塞泵具有较小的流量脉动,是一种比较理想的选择。 相似文献
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非对称轴向柱塞泵直接闭式控制单出杆液压缸系统具有结构紧凑、能效高和噪声低的优势,其排量控制特性直接影响泵控系统运行特性。基于此,提出基于斜盘摆角位移反馈的排量控制方案,根据电液比例排量调节工作原理,考虑弹性负载刚度及外负载力干扰的影响,建立了非对称轴向柱塞泵的变排量控制系统模型。通过MATLAB/Simulink仿真分析了不同活塞直径、负载刚度、斜盘摆角、负载压力对泵的出口流量动态特性的影响。仿真结果表明,减小液压缸活塞直径、增大负载刚度可以加快响应速度;增大负载压力可以提高响应稳定性。通过实验验证了仿真结果正确性,实验表明非对称泵的变排量工作性能稳定可靠。 相似文献
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In this study, the lubrication characteristics of a slipper bearing for axial piston pump considering oil thermal effect have been investigated. A mathematical model is developed to predict the film thickness and temperature on the slipper/swash plate interface under different operating conditions. Based on the mathematical model, a parametric study is conducted to evaluate the slipper lubrication performance. It is found that the slipper is characterised by an unstable behaviour and the behaviour is enhanced by lower pressure and higher rotational speed. As the film temperature increases rapidly due to high shaft speed and piston chamber pressure, the overall result is a rather low decline in the film thickness. The leakage flow rate increases with increasing speed or oil film thickness. The structure parameter can be optimised to obtain satisfactory slipper performance. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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浮杯原理是继斜盘式和斜轴式之后一种新的轴向柱塞概念,将现有泵原理的优点结合在了一起。最显著特征是结构镜像对称设计以及柱塞固接在转子上,且每个活塞对应一个独立的杯状缸筒,它可以沿旋转斜盘面自由浮动。浮杯泵具有结构紧凑、质量小、泄漏小、受力平衡、力矩损失小、波动小、噪声小、效率高、生产成本低等优点。浮杯原理将被广泛应用在液压定量和变量泵、液压变压器和液压马达等方面。该文针对浮杯泵的研发现状、结构特点、优点等方面进行了详细的分析和梳理,对浮杯原理在定量/变量泵、液压变压器、液压马达的应用发展状况进行了介绍。该文将为浮杯泵的进一步研发及浮杯原理更广泛应用提供参考。 相似文献
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为研制变排量非对称轴向柱塞泵,依据三配流窗口轴向柱塞泵的配流思想,提出基于斜盘摆角位置反馈的排量控制方案,建立变排量非对称轴向柱塞泵的数学模型,对其频率响应影响因素进行分析。通过AMESim对该泵的变排量特性进行研究,仿真结果表明:当配流窗口A吸油、配流窗口B和T排油时,柱塞对斜盘的合力作用点轨迹具有较长的作用力臂,若配流窗口B和T压差过大,则斜盘摆角减小时响应将显著降低;当配流窗口B和T吸油、配流窗口A排油时,柱塞对斜盘的合力作用点轨迹与对称式轴向柱塞泵相似,配流窗口A压力对斜盘响应影响较小。通过试验验证了仿真模型的正确性,同时试验表明该泵具有较好的动态特性。 相似文献
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轴向柱塞泵配流副润滑特性的研究进展 总被引:8,自引:0,他引:8
介绍了国内外有关轴向柱塞泵配流副润滑特性方面的研究成果,并进行了综合分析和比较。指出需借鉴国外现有的关于轴向柱塞泵配流副压力分布规律的理论,确定最佳剩余压紧系数,现有的配流副结构设计方法和理论依据需进一步完善。建立了轴向柱塞泵配流副润滑特性试验平台,可在不同压力、温度、转速、结构下测试配流副间隙并得出配流副润滑膜的形成及变化规律。通过润滑特性测试平台还可以确定最佳水液压柱塞泵配流副润滑结构和材料配对,为研制出性能良好的轴向柱塞式水液压泵奠定实验基础。 相似文献
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A numerical procedure to analyze wavy thrust bearings is described. The numerical model is developed by assuming that two circular plates rotate relative to each other. The upper plate is assumed to be flat and rotating, whereas the lower plate is assumed to be stationary and wavy in surface geometry. A Reynolds-equation-based procedure is used to simulate the dynamics engendered by various wavy geometries and loading conditions. The equilibrium position of the journal results from the equilibrium between the forces generated by the fluid-film pressures and the externally applied loads. A numerical small perturbation technique is applied to calculate the linear stiffness and damping characteristics of the bearing at the equilibrium position. Using a three-degrees-of-freedom system with one axial and two rotational displacements, nine linear stiffness coefficients (three principal and six cross-coupled coefficients) and nine linear damping coefficients are calculated. These linear coefficients are then used to calculate the eigenvalues of the system by solving the homogeneous equations of motion. The stability of the bearing system is then expressed using the lowest logarithmic decrement obtained from these eigenvalues. Using this procedure, a parametric study is carried out to examine the effects of external load, location of the applied load, bearing number, and bearing wave amplitude on journal equilibrium position, bearing linear stiffness, damping characteristics, and bearing stability. 相似文献