斜盘泵滑靴副剧烈磨损过程的动态特性分析

斜盘泵在发生滑靴副磨损故障时表现出与正常状态下完全不同的动态特性。为深入分析滑靴磨损量对滑靴副动态特性的影响,在不考虑滑靴倾斜的条件下,建立了描述滑靴剧烈磨损的动力学模型。通过对滑靴磨损过程的发展机理分析,采用近似圆弧进行拟合的方法得到磨损量与磨损轮廓的数学描述方程;同时给出滑靴磨损状态的压力控制方程、膜厚方程、流量平衡方程和力平衡方程,由此建立滑靴在压油区的动力学模型。通过数值分析得出磨损量与滑靴副泄漏量、压力分布、滑靴承载力以及最小油膜厚度之间的变化规律。结果表明:滑靴泄漏量随滑靴磨损量的增加而变大,从而加快滑靴底面油膜压力沿滑靴径向的递减速度,进而降低滑靴的承载力,减小滑靴的最小油膜厚度,削弱滑靴副适应载荷变化的能力。     

考虑表面接触力的滑靴副油膜特性分析方法

由于受倾覆力及刚体表面粗糙度影响,液压柱塞泵斜盘-滑靴运动副(滑靴副)在相对运动时处于混合润滑状态。斜盘和滑靴表面接触引起弹性和塑性变形,进而产生表面接触力。接触力与油膜厚度密切相关,在油膜特性分析时不应被忽略。提出一种基于流体动压润滑理论的滑靴副油膜特性(油膜厚度、压力分布、油膜间隙流量)的分析与计算方法,考虑了滑靴副粗糙表面的支撑力影响。在雷诺流体动压润滑方程基础上,考虑滑靴副刚体表面粗糙度水平和油膜厚度,计算液压柱塞泵不同工况下的表面接触支撑力,并将接触力融入运动副的受力方程。提出了基于改进的雷诺流体动压润滑方程的数值计算方法,并进行了仿真分析,通过间接对比滑靴副间隙流量的仿真结果,证实了提出方法的有效性和结果的准确性。     

基于CFD的轴向柱塞泵滑靴副的流场仿真

在斜盘式轴向柱塞泵中,滑靴副是主要的摩擦副之一。对滑靴副油膜的形成和流动状况的研究,对于改善其偏磨、烧盘等现象,增加使用寿命,减小泄漏量,提高泵的整体性能有着重要的意义。利用CFD技术对滑靴副流场进行模拟分析,得出压力分布,与通过静压平衡理论公式的计算结果对比,通过仿真结果定量直观地分析了造成磨损的原因,同时说明油膜了在滑靴副中的重要作用。分析表明,滑靴副的结构及其油膜的作用是减小磨损的重要方面。运用Fluent模拟仿真的结果和理论公式计算得出的结果基本吻合,说明Fluent仿真的可行性。     

强冲击载荷对滑靴副磨损过程承载特性的影响

超负荷加载运行是使液压泵寿命加速退化的常用方法,强冲击载荷是其中一种有效的加载形式,为研究强冲击载荷作用下滑靴副磨损过程的承载特性变化规律及液压泵寿命退化机制,考虑滑靴沿斜盘表面的倾覆,建立滑靴副正常状态的承载特性方程;通过确定冲击载荷作用产生磨损的条件,定义滑靴底面磨损轮廓结构参数,推导滑靴副在强冲击载荷作用下磨损过程的油膜承载特性方程,探索强冲击载荷对油膜压力分布、油膜厚度分布以及抗冲击载荷参数的影响。分析结果表明:随着强冲击载荷和冲击次数的增加,最小油膜厚度均有减小的趋势;而随着强冲击载荷冲击次数的增加,滑靴磨损量将逐步增大,在磨损轮廓处油膜厚度将逐渐减小,油膜压力将逐渐降低;密封带宽度将逐渐变窄,抗冲击载荷能力将逐渐变弱且磨损程度愈发严重。     

静压支承式滑靴副油膜动态特性研究

考虑斜盘式轴向柱塞泵滑靴副油膜的挤压效应,不考虑滑靴倾覆,分析了滑靴副润滑油膜的动态特性,包括压力跃变响应与实泵输入响应,并分析了滑靴副结构参数对于油膜动态响应的影响。分析结果表明,减小滑靴中心油室的体积,有利于改善油膜动态响应品质,但油室体积不能过小;为兼顾滑靴副动态润滑特性与泄漏量,需要合理设计阻尼管的液阻;在保证建立油膜的情况下,缝隙阻尼的有效支承面积越小,滑靴副动态油膜的润滑品质越好。实泵输入动态响应中,在高低压区工作时,油膜的压力变化虽然较大,但静压支承式滑靴膜厚的波动范围很小。     

液压柱塞泵运动副磨损特性研究综述

针对液压柱塞泵的3对主要运动副:柱塞-缸体副(柱塞副)、缸体-配流盘副(配流盘副)、斜盘-滑靴副(滑靴副),对国内外围绕3对运动副磨损特性相关的研究进行了汇总和总结。柱塞泵运动副间隙的润滑形式为粘弹性动力润滑(EHL),磨损特性与油膜、介质、污染、运动副材料及表面形貌等密切相关。主要介绍了柱塞泵运动副的润滑磨损理论研究,影响磨损特性的运动副油膜特性相关研究成果,以及适用于柱塞泵运动副的磨损模型。对比分析了柱塞泵磨损特性研究常用的解析方法、仿真方法、实验方法,介绍了每种方法的优势及局限性。最后对影响柱塞泵运动副磨损特性的关键因素进行了总结,给出了有待解决的问题及研究方案。     

液压马达柱塞滑靴小孔堵塞影响分析

一、节流小孔的作用原理斜盘式输向柱塞液压马达柱塞及沿靴中心均设有节流小孔。该小孔不仅将压力油引到球面和平面间进行润滑，更重要的是，在滑靴端面与斜盘表面间形成能承受一定负载的动力油膜，使滑靴浮起，从而极大地减少两表面间的摩擦，减小二者的磨损，提高其使用寿命。二、小孔堵塞影响的分析滑靴的工作原理见图1。（1）若液压马达柱塞小孔f或滑靴小孔g因某种原因堵塞，造成无压力油进入滑靴端面与斜盘表面间的油腔A内，在两表面间形不成油膜，不能使滑靴浮起。在油压产的作用下，使滑靴与斜盘紧贴在一起对磨，所产生的摩擦力严重…     

轴向柱塞泵滑靴副楔形油膜特性分析

轴向柱塞泵工作过程中,滑靴会在倾覆力矩作用下相对于斜盘表面形成一定的楔形油膜,在油膜静压支承力和油膜动压效应和挤压效应作用下滑靴副楔形油膜压力场始终与滑靴所受的外力和外力矩处在动态的平衡中。本文采用一种新的研究方法对滑靴油膜动态特性进行研究,用牛顿迭代算法对滑靴受力/力矩情况和滑靴副油膜的耦合关系进行研究。在Matlab软件中以低层编程的方法揭示滑靴副楔形油膜动态特性,从而对滑靴副工作特性进行预测。     

基于润滑机理的智能液压元件本体性能预测方法

以液压泵为例,以其最为薄弱的环节--滑靴副为研究对象,并以滑靴磨损作为性能退化原因,结合滑靴磨损数学描述方程、泄漏流量公式和柱塞腔压力瞬时变化模型,建立了滑靴磨损过程的油膜润滑特性方程组;揭示了液压泵性能失稳失效机理,计算了失稳和失效临界点;对液压泵性能退化状态进行区域划分,分析液压泵不同状态下滑靴磨损量与油膜润滑特性参数及性能退化参数的变化规律,建立了性能预测模型;通过仿真分析验证理论模型的正确性,通过液压泵性能测试试验验证预测模型的有效性和预测精度,结果表明,所构建的模型能够精确预测液压泵性能。     

轴向柱塞泵滑靴副润滑特性分析

滑靴副的润滑特性直接影响着轴向柱塞泵的效率和使用寿命等工作性能,而油膜厚度和承载力是其衡量润滑特性的重要指标,为此开展柱塞泵滑靴副的油膜厚度及承载力的研究。在静压支承的基础上确立了滑靴副油室压力反馈模型,根据损失功率最小求得最佳油膜厚度,计算滑靴密封带处油膜压力分布。再通过建立滑靴副三维流道模型,进行流体仿真验证压力计算数值模型。理论模型和数值分析揭示了轴向柱塞泵滑靴副油膜承载能力的变化规律,为液压源的设计和开发打下了理论基础。     

Experimental Research on the Dynamic Lubricating Performance of Slipper/Swash Plate Interface in Axial Piston Pumps

The interface between the slipper/swash plate is one of the most important frication pairs in axial piston pumps. The test of this interface in a real pump is very challenging. In this paper, a novel pump prototype is designed and a test rig is set up to study the dynamic lubricating performance of the slipper/swash-plate interface in axial piston machines. Such an experimental setup can simulate the operating condition of a real axial piston pump without changing the relative motion relationship of the interfaces. Considering the lubricant oil film thickness as the main measurement parameter, the attitude of the slipper under the conditions of different load pressure, rotation speed and charge pressure are studied experimentally. After the test, the wear state of the swash plate is observed. According to the friction trace on the surface of the swash plate, the prediction for the attitude of the slipper and the zone easy to wear are verified.     

轴向柱塞泵滑靴的动力学特性仿真分析

滑靴与斜盘、柱塞、回程盘之间的配合是保证柱塞泵正常工作的重要条件,滑靴的磨损失效会影响与之配合零件的正常工作。首先对A4VG125型柱塞泵滑靴进行理论受力分析,应用SimulationX建立柱塞泵的一维液压模型和三维MBS模型,仿真柱塞底部所受液压力。然后与ADAMS和ANSYS建立的柱塞泵动力学模型进行联合,完成柱塞泵的刚柔与液固耦合仿真模型。在仿真工作参数作用下,研究滑靴与斜盘、柱塞、回程盘之间摩擦副的动力学特性。结果表明:当斜盘倾角增大、主轴转速提高时,对滑靴总体的受力/力矩情况影响较大;滑靴与柱塞之间的球铰副受工作参数变化影响较为明显,受力/力矩波动较为严重。     

Tribological study on hydrostatic slipper bearing with annular orifice damper for water hydraulic axial piston motor

Hydrostatic slipper bearing is an effective way to maintain a fluid film between slipper pad and swash plate that slide against each other, and thereby mitigate direct surface-to-surface contact in water hydraulic axial piston motor (WHAPM). The hydrostatic slipper bearing with an annular orifice damper is proposed, and the reaction force of the bearing in WHAPM is investigated. The effects from the friction within the cylinder bore, the dynamics of the piston, and the centrifugal force of the piston–slipper assembly are examined. The characteristic equation of the hydrostatic slipper bearing with an annular orifice damper is formulated, where the effects of various geometric parameters (e.g. damping length, supporting length, and clearance between the piston and the cylinder bore) are reflected. The relevant criterion for designing the hydrostatic slipper bearing can then be established. Results of the theoretical analyses indicate that (a) the friction coefficient, the swash plate angle, and the inertia and centrifugal loads (generated under a high motor rotating speed) would have significant influences on the reaction force; (b) an appropriate swash plate angle can help eliminate the fluctuation of the reaction force; (c) the load-carrying capacity of the hydrostatic slipper bearing is more sensitive to the damping length than to the supporting length of the piston; (d) a short damping length can help enhance the load-carrying capacity; (e) a small clearance between the piston and the cylinder bore would help improve the adaptive ability to the varying load for the hydrostatic slipper bearing, when clearance between the slipper pad and the swash plate ranges from 5 to 20 μm. Experimental studies of the slipper pads sliding against the swash plates are conducted at a custom-manufactured test apparatus, given different material combinations and design methods. The experimental results indicate that the hydrostatic slipper bearing with an annular orifice damper would decrease the possibility of the severe wear between the slipper pad and the swash plate in comparison with the hydrostatic clamping ratio bearing in the WHAPM, and the CRA laser cladding (compared to the ZrO₂·MgO-plasma-sprayed coating and the stainless steel 2Cr13) is a promising candidate as the tribo-material when sliding against composite materials in water lubrication system. The hydrostatic slipper bearing with an annular orifice damper has been successfully applied to a WHAPM developed at the Huazhong University Science and Technology. The result demonstrates that the developed bearing has a satisfactory tribolgical performance, and can be extended to the manufacture of water hydraulic axial piston pumps.     

Integrated slipper retainer mechanism to eliminate slipper wear in high-speed axial piston pumps

The power density of axial piston pumps can greatly benefit from increasing the speed level. However, traditional slippers in axial piston pumps are exposed to continuous sliding on the swash plate, suffering from serious wear at high rotational speeds. Therefore, this paper presents a new integrated slipper retainer mechanism for high-speed axial piston pumps, which can avoid direct contact between the slippers and the swash plate and thereby eliminate slipper wear under severe operating conditions. A lubrication model was developed for this specific slipper retainer mechanism, and experiments were carried out on a pump prototype operating at high rotational speed up to 10000 r/min. Experimental results qualitatively validated the theoretical model and confirmed the effectiveness of the new slipper design.     

Lubrication characteristics analysis of slipper bearing in axial piston pump considering thermal effect

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.     

A11VLO190轴向柱塞泵柱塞副泄漏与润滑特性研究

将轴向柱塞泵柱塞副的泄漏看做偏心圆环缝隙的流动,使用Matlab进行仿真,分析得到了柱塞副泄漏量与负载压力、配合间隙、工作转速和斜盘倾角的关系。采用有限差分法求解二维雷诺方程,该文在考虑油膜动压效应和挤压效应的条件下,得到了柱塞在缸体内的倾角、柱塞自转速度、进口压力对柱塞副油膜分布压力的影响,为提高柱塞副的效率、改善润滑、减少摩擦磨损和增加使用寿命提供了一些参考意见。     

盾构机液压柱塞泵损坏原因解析

该文分析斜轴式液压柱塞泵损坏原因及柱塞滑靴与斜盘摩擦副静压油膜机理,论述不同转速、压力下滑靴油膜特性。     

海水液压柱塞泵中新型滑盘副的设计及其润滑特性研究

传统海水液压柱塞泵中,滑靴的固有结构形式使其易发生偏磨、烧靴等问题。提出了一种新型滑盘结构,从根本上消除了因离心力产生的滑靴倾覆问题,并减小了柱塞所受的侧向力。建立了滑盘副润滑数学模型,并分析了温度和工况参数对滑盘副的润滑特性及能耗特性的影响。结果表明：随着介质温度的升高,滑盘副的动压效应减弱,水膜厚度减小,导致泄漏量降低;同时,黏度随温度升高而降低,滑盘所受到的摩擦力减小,黏性摩擦功率损失降低;随着泵工作压力的升高,水膜厚度变大,泄漏量增大,相反黏性摩擦功率损失降低;而随着泵的工作转速的增大,滑盘副的泄漏量功率损失和黏性摩擦功率损失均有所增加。