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液体静压支承 2

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Dynamic modeling of hydrostatic guideway considering compressibility and inertia effect

Yikang DU,Kuanmin MAO,Yaming ZHU,Fengyun WANG,Xiaobo MAO,Bin LI

《机械工程前沿（英文）》 2015年第10卷第1期页码 78-88 doi: 10.1007/s11465-015-0331-4

摘要：

Hydrostatic guideways are used as an alternative to contact bearings due to high stiffness and high damping in heavy machine tools. To improve the dynamic characteristic of bearing structure, the dynamic modeling of the hydrostatic guidway should be accurately known. This paper presents a “mass-spring-Maxwell” model considering the effects of inertia, squeeze, compressibility and static bearing. To determine the dynamic model coefficients, numerical simulation of different cases between displacement and dynamic force of oil film are performed with fluent code. Simulation results show that hydrostatic guidway can be taken as a linear system when it is subjected to a small oscillation amplitude. Based on a dynamic model and numerical simulation, every dynamic model’s parameters are calculated by the Levenberg-Marquardt algorithm. Identification results show that “mass-spring-damper” model is the most appropriate dynamic model of the hydrostatic guidway. This paper provides a reference and preparation for the analysis of the dynamic model of the similar hydrostatic bearings.

关键词： hydrostatic guidway dynamic model dynamic mesh technique Levenberg-Marquardt mass-spring-damper model

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Influence of boundary conditions and turntable speeds on the stability of hydrostatic oil cavity

Zhaomiao LIU, Chengyin ZHANG, Feng SHEN

《机械工程前沿（英文）》 2011年第6卷第3期页码 359-368 doi: 10.1007/s11465-011-0222-2

摘要：

The flow, bearing, and carrying capacity of the cycloidal hydrostatic oil cavity in hydrostatic turntable systems are numerically simulated, considering the rotation speeds of a turntable from 0 to 5 m/s and different boundary conditions. The vortex effect is weakened, and the stability of the oil cavity is enhanced with the increase in lubricant viscosity. However, the increase in inlet speed, depth, and inlet radius of the oil cavity causes the vortex effect to increase and the stability of oil cavity to reduce. With the increase in the oil film thickness, the carrying capacity of the oil cavity diminishes. The oil cavity pressure increases along the direction of the motion of the turntable; it is distributed unevenly because of the rotation of the turntable. With the increase in turntable speed, the location and size of the vortex scope in the oil cavity flow field and the strength of the vortex near the entrance gradually weaken and move away from the entry. The distribution of pressure is determined by the locations of the vortex. When the vortex is close to the wall, the wall pressure increases at its location. Otherwise, the wall pressure decreases first and then increases after the center of the vortex.

关键词： hydrostatic oil cavity flow state oil cavity pressure stability vortex

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液体静压支承动态性能新表达式探索与实验验证

孟心斋,杨建玺,孟昭焱

《中国工程科学》 2003年第5卷第3期页码 62-66

摘要：

液体静压支承具有很多优良性能：高运动精度，低摩擦功耗，小轴心偏移，大承载能力，强抗振性能与长使用寿命等，但这些优良的静态性能必须在上佳的动态性能保证下才能充分显示出来，因此，液体静压支承静态性能保证机床运动与加工精度，而动态性能则保证设备的安全与工作条件。文章根据力平衡与流量连续条件建立支承系统传递函数，导出支承系统动态性能新表达式即稳定性判别、抗瞬态干扰能力、固有频率与在稳态周期干扰力作用下产生的动刚度与最大振幅。通过试验台实验证实，液体静压支承动态性能新表达式计算结果可靠而且物理概念清晰，公式简单，故可用于实际。

关键词：动态性能传递函数动刚度谐振频率液体静压支承

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液体静压支承静态性能新表达式探索

孟心斋,杨建玺,孟昭焱

《中国工程科学》 2002年第4卷第5期页码 63-66

摘要：

文章分析了液体静压支承传统的静态性能表达式存在的严重缺陷及其产生原因，提出了新的静态性能表达式。这种新的静态性能表达式精确地表达了外加载荷与轴承间隙之间的非线性关系，真实地反映了支承的静态性能。新的静态性能通用表达式可表达各种传统节流器与新型可变节流器节流时支承的主要静态性能，很有应用价值。新的静态性能表达式只有一个变量即外加载荷与油垫推力比，故可在支承节流与尺寸参数未确定之前知道支承的主要静态性能，它有利于事先选择与确定支承在应用时的主要性能，为正确应用液体静压支承提供了可靠的技术基础。

关键词：液体静压支承传统节流器新型可变节流器静态性能

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Changes in structure and functional properties of whey proteins induced by high hydrostatic pressure:

Xiaoming LIU, Jia NING, Stephanie CLARK,

《化学科学与工程前沿（英文）》 2009年第3卷第4期页码 436-442 doi: 10.1007/s11705-009-0251-0

摘要： High hydrostatic pressure (HHP) is an alternative technology to heat processing for food product modifications. It does not cause environmental pollution and eliminates the use of chemical additives in food products. This review covers the research conducted to understand the effect of HHP on structure and functional properties of whey proteins. In this paper, the mechanism underlying pressure-induced changes in -lactoglobulin and -lactabumin is also discussed and how they related to functional properties such as hydrophobicity, foam stability, and flavor-binding capacity.

关键词： -lactoglobulin processing functional alternative technology environmental

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Equivalent thermal conductivity of heat pipes

LU Zesheng, MA Binghui

《机械工程前沿（英文）》 2008年第3卷第4期页码 462-466 doi: 10.1007/s11465-008-0087-1

摘要： In precision machining, the machining error from thermal distortion carries a high proportion of the total errors. If a precision machining tool can transfer heat fast, the thermal distortion will be reduced and the machining precision will be improved. A heat pipe working based on phase transitions of the inner working liquid transfers heat with high efficiency and is widely applied in spaceflight and chemical industries. In mechanics, applications of heat pipes are correspondingly less. When a heat pipe is applied to a hydrostatic motorized spindle, the thermal distortion cannot be solved during the heat transfer process because thermal conductivity or equivalent thermal conductivity should be provided first for special application in mechanics. An equivalent thermal conductivity model based on equivalent thermal resistances is established. Performance tests for a screen wick pipe, gravity pipe, and rotation heat pipe are done to validate the efficiency of the equivalent thermal conductivity model. The proposed model provides a calculation method for the thermal distortion analysis of heat pipes applied in the motorized spindle.

关键词： proposed distortion analysis hydrostatic motorized motorized spindle Performance

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Multi-objective optimization of surface texture for the slipperswash plate interface in EHA pumps

《机械工程前沿（英文）》 2022年第17卷第4期 doi: 10.1007/s11465-022-0704-4

摘要： Well-designed surface textures can improve the tribological properties and the efficiency of the electro-hydrostatic actuator (EHA) pump under high-speed and high-pressure conditions. This study proposes a multi-objective optimization model to obtain the arbitrarily surface textures design of the slipper/swash plate interface for improving the mechanical and volumetric efficiency of the EHA pump. The model is composed of the lubrication film model, the component dynamic model considering the spinning motion, and the multi-objective optimization model. In this way, the arbitrary-shaped surface texture with the best comprehensive effect in the EHA pump is achieved and its positive effects in the EHA pump prototype are verified. Experimental results show a reduction in wear and an improvement in mechanical and volumetric efficiency by 1.4% and 0.8%, respectively, with the textured swash plate compared with the untextured one.

关键词： electro-hydrostatic actuator axial piston pump slipper/swash plate interface multi-objective optimization surface texture

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静液驱动二次调节扭矩加载系统实验

战兴群,张炎华,赵克定

《中国工程科学》 2001年第3卷第11期页码 70-73

摘要：

针对柔性航天器动力学模型的降阶问题，综述了动力学建模中几种常用的模态集，介绍了用于选择系统保留模态的有关准则。通常的模态价值分析和内平衡理论是用于航天器系统模态的选取，而不是直接用于动力学建模时的部件模态或系统结构弹性变形模态的选取，因而存在如何应用上述准则于动力学建模的问题。为此，提出了一个动力学建模时的降阶策略；还提供了一个数值例子，以对采用不同的模态集建模时的结果进行比较，并表明如何采用上述准则于航天器的动力学建模。

关键词：航天器柔性体动力学模型降阶

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节流性能优异的新型液体静压支承节流器

孟心斋,孟昭焱

《中国工程科学》 2005年第7卷第3期页码 49-52

摘要：

传统的液体静压支承节流器存在严重缺陷，性能不佳，不能消除支承间隙随外加载荷增加而剧减的缺点，严重影响其实际应用。新型节流器节流变量指数b≥3，能够保持节流器进油与油囊排油速度接近一致。此外，当有外加载荷作用于支承时，油囊压力会升高，迫使节流变量产生附加增量，从而弥补了因油囊压力升高而减少供油量与油囊增加的排油量。因此，新型节流器能够保证在有外加载荷作用时支承间隙变化很小或近于不变。新型节流器节流性能优良，结构简单，成本低廉，体积较小，具有实用价值。

关键词：变隙滑阀节流器变隙薄板节流器变径毛细管节流器节流变量指数

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二次调节扭矩加载系统动态特性的研究

战兴群,张炎华,赵克定

《中国工程科学》 2000年第2卷第7期页码 47-54

摘要：

静液驱动二次调节技术是一项新型的液压传动技术。它具有控制方便、容易组成类似于电气系统的网络执行机构以及液压能回收与重新利用，甚至比电气系统更为简便等一系列突出的优点。二次调节技术的研究将极大地提高液压传动技术的应用范围和产品的竞争力。扭矩伺服加载系统是二次调节技术研究的一个典型装置，同时它也具有很好的应用背景。文章通过对二次调节加载装置全系统建模，分析了二次调节技术的一些内在动态特性，建立了二次调节扭矩加载计算机控制系统，用部分实验曲线验证了理论分析的正确性。

关键词：静液驱动二次调节加载数学模型动态特性