油气润滑最佳供油量研究

研究了不同的工况参数s与所需的润滑油供油量的关系,发现在不同工况参数s下都存在最佳的供油量.通过试验和分析,得到系统所需供油量与系统工况参数s之间的关系式,应用该公式可以预测轴承-主轴系统的最佳供油量.     

高速轧辊磨床主轴系统动静压轴承供油液压系统的开发

介绍了普通轧辊磨床主轴系统动静压轴承供油方式的特点,并对常用的普通动静压轴承的恒流量供油系统和恒压供油系统进行了详细的对比分析,在此基础上,设计了高速轧辊磨床主轴系统动静压轴承的供油液压系统,结果表明,相较于常用的普通动静压轴承的恒压供油系统,高速动静压轴承的恒压供油系统的压力稳定性更好,压力调节更方便和可靠.     

航空发动机主供油路压力脉动仿真分析

供油系统工作性能的好坏将直接影响到发动机的工作性能与使用寿命。为了寻找解决供油压力脉动现象的途径,需模拟供油系统典型工作状态下的压力脉动情况。采用理论分析和数值仿真相结合的方法,基于AMESim仿真平台建立供油系统各部件模型,通过仿真结果与实验结果的对比,验证仿真方法的正确性。结果表明溢流阀弹簧预紧力、弹簧钢度和阀座直径均对主供油路压力值及脉动幅值产生影响。计算在溢流阀出口处增设蓄能器的情况,发现主供油路压力脉动程度明显减小,为供油系统的优化提供依据。     

柴油机供油系统的检测与研究

柴油机的油压波形中包含了大量可作为供油系统故障诊断的特征参数。本文通过对供油压力波形分析研究,提取故障诊断特征参数,设计了油压的检测诊断系统。实验表明,这种供油系统的检测与诊断方法是有效的、可行的。     

气液蓄能器供油系统的辨认与调整

气液蓄能器供油系统(泵-气液蓄能器供油系统的简称)理想的情况是,流量和压力的变化完全一致。但是,绝大多数的系统并非如此,往往是能满足执行器速度要求就不能满足其压力要求,从而导致与容积变化对应的压力出现一定的差值。要使各式各样的气液蓄能器供油系统正常工作,须对它们进行辨认及调整。     

供油系统设计概述

本文阐述了供油系统的性能要求,并结合实践详述了供油系统的开发流程,以及供油系统各零件的性能要求。     

基于模糊控制的供油系统改进

对现有钢板静电涂油机的液压供油系统进行了分析。针对其不足进行了改进设计．研制出新型的性能更好的液压供油系统，并采取参数自调整模糊控制算法提高了液压供油系统的响应速度及稳定性。     

机场油库操作管理仿真系统开发

机场油库及机场供油的主要对象是易燃、易爆且质量要求更高的成品油——航空煤油。其生产系统工艺流程复杂,误操作的后果严重,是高危作业场所。实际生产基地远离城市且严禁无资质人员操作,搭建实物实验设备耗资巨大存在安全风险且场地有限,这直接影响学生动手能力的培养,缺乏创新意识。鉴于此,开发了一套民航机场供油仿真系统。本仿真系统综合国内多家机场的现场生产数据,并参照国标文献,使用可视化技术(Visualization)、交互技术(Interaction)和优化技术(Optimization)设计而成,基于C语言、Action Script和蚁群算法进行开发。本系统由两部分组成:民航机场供油简介系统和机场供油实时仿真系统。本仿真系统通过控制供油系统中泵与阀等管件的启闭,可模拟整套机场供油系统中油库的收油、管线的供油、机场的加油等工艺流程,同时实时显示油罐内液位与管道压力、流量等参数变化,使操作者能及时观察了解每一种安全工况和事故工况下理论知识的完美呈现。     

静电涂油机的供油系统改型

对现有钢板静电涂油机的液压供油系统进行了分析.针对其不足进行了改进设计,研制出新型的性能更好的液压供油系统,并采取参数自调整模糊控制算法提高了液压供油系统的响应速度及稳定性.     

油田注汽站脱氧塔液位及供油系统的自控技术升级

在分析油田注汽站脱氧系统及供油系统自动控制的基础上,提出应用变频节能装置自动控制脱氧系统液位及恒压供油系统的控制方案,实施后取得明显效果。     

Effect of working position on vertical motion straightness of open hydrostatic guideways in grinding machine

Hydrostatic guideways have various applications in precision machine tools due to their high motion accuracy. The analysis of motion straightness in hydrostatic guideways is generally ignoring the external load on the slider. A variation force also exists, caused by the different working positions, together with the dead load of the slider and that of other auxiliary devices. The effect of working position on vertical motion straightness is investigated based on the equivalent static model, considering the error averaging effort of pressured oil film in open hydrostatic guideways. Open hydrostatic guideways in LGF1000 are analyzed with this approach. The theoretical results show that the slider has maximum vertical motion straightness when the working position is closer the guiderail of Y axis. The vertical motion straightness reaches a minimum value as the working position is located at the center of the two guiderails on the Y axis. The difference between the maximum and minimum vertical motion straightness is 34.7%. The smaller vertical motion straightness is attributed to the smaller spacing of the two pads centers, along the Y direction. The experimental results show that the vertical motion straightness is 4.15 μm/1200 mm, when the working position is located in the middle of the X beam, and 5.08 μm/1200 mm, when the working position is approaching the Y guiderails, denoting an increase of 18.3%. The changing trends of the measured results validate the correctness of the theoretical model. The research work can be used to reveal the variation law of accuracy of the open hydrostatic guideways, under different working positions, to predict the machining precision, and provides the basis for an error compensation strategy for gantry type grinding machines.     

扇形静压转台结构设计与仿真分析

为解决平面二次环面蜗杆数控磨床加工中出现形位超差和精度不足的问题,通过研究磨床的整体结构和转台工况确定了扇形静压转台的主体结构方案和设计参数,通过理论计算推导出承载力与位移率和面积比的关系和刚度与压力比与面积比的关系,根据面积比最优计算得到油垫的承载力和刚度,并利用FLUENT软件分别对口字型和工字型油腔结构的油垫进行流体力学仿真分析,证明计算得到的油腔尺寸参数可以使转台产生足够的承载力,满足磨床设计要求,分析了矩形油垫中不同的油腔内部结构,得到口字型油腔结构比工字型油腔结构产生的更大承载能力且承载更均匀,油腔内部无内壁阻隔更适合于静压油腔选型的结论。     

Effect of self-assembled monolayers modified slider on head-disk tribology under volatile organic contamination

Self-assembled monolayers (SAMs) with different endgroups were established on slider surface. The effect of the SAMs coated slider on head-disk tribology under volatile organic contamination (VOC) of octamethylcyclotetrasiloxane (D₄) was investigated using a contact start/stop (CSS) tester. The slider surfaces before and after the CSS tests were analyzed using Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). The contact angle measurement and TOF-SIMS analysis proved that the SAMs were successfully formed on the slider surface. All the SAMs reduced the friction under the pollutant vapor. The transfer of lubricating oil onto the slider surface was detected after the CSS tests. It was found that the slider with a low surface free energy associated with small amount of lubricating oil transfer. The little the lubricating oil transfer was, the low the frictions were. These results indicate that a slider with low surface free energy can reduce the loss of lubricating oil from the disk surface, and hence improve the tribological properties of hard-disk interface (HDI) under VOC.     

液体圆柱静压导轨设计参数对其性能的影响

为研究液体圆柱静压导轨的初始参数对导轨性能的影响,以内反馈节流形式的液体圆柱静压导轨为研究对象,列出力平衡方程、流量连续性方程,经推导和线性化处理得到液体圆柱静压导轨的线性化微分方程组,利用Laplace变换得到传递函数,推导出液体圆柱静压导轨的数学模型。从时域、频域内分别分析初始油膜厚度、油液黏度、供油压力对导轨性能的影响。研究表明在低频段减小初始油膜厚度、增大油液黏度和供油压力,在高频段增大初始油膜厚度,可增大导轨动态刚度,提高支承的稳定性,减小导轨间隙相对稳态位移值。在高频段,油液黏度、供油压力对液体圆柱静压导轨的动态性能影响不大。研究工作对液体圆柱静压导轨的设计提供参考价值。     

滚滑轴承滑块的油-气两相流润滑分析

为改善滚滑轴承的润滑,运用两相流理论对其滑块进行油气润滑设计,建立滑块的油-气两相流CFD模型,分析不同入口角度、进气速度、进油速度和润滑油黏度对流场油相分布的影响。结果表明:油-气混合润滑方式能在内外滚道接触区形成有效的润滑油膜;油气管道夹角影响油滴分布,角度过大时大量油滴会在滑块侧面上附着,角度过小时油滴会在外滚道入口处堆积,造成供油连续性不好,油膜稳定性下降;进气速度过大会降低油滴附着率,无法形成有效油膜,而进油速度过大会造成润滑油累积,出现搅油现象,因此选择合适的进气和进油速度,才能控制油滴的大小和保持润滑过程的连续性;润滑油黏度会影响油滴在滑块上的附着效果,合理地选择润滑油黏度,才能保证流场油相分布均匀。     

Effect of volatile organic contamination on head-disk interface tribology and a method for its reduction

Volatile organic contamination is known to be one of the factors to cause the failure of head-disk interface (HDI). Therefore, reduction of its harmful effects and improvement of the stability and reliability of HDI is becoming an important issue. In this study, the effects of some model compounds of volatile organic contamination on the tribological characteristics of HDI were systematically investigated using a contact start/stop (CSS) tester. The slider surface after the CSS tests was analyzed using Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). Transfer of lubricating oil onto the slider surface was detected after the CSS tests. The organic contaminants promoted the transfer and resulted in high and unstable friction force. Fluorinated self-assembled monolayers (SAMs) were applied on the slider surface for reducing the transferred amount of the lubricating oil. Tribological performance of the slider coated with the SAMs and the transfer amount of lubricating oil onto the slider surface in the presence of contaminant was investigated. The friction force was low and stable in the case of the SAMs coated slider even under environmental contaminant. This result could be explained by the reduction of the transferred lubricating oil because the SAMs that coated on the slider surface were low surface energy.     

轴向柱塞泵配流副油膜试验原理及控制特性

为研究油、水介质下轴向柱塞泵几类关键摩擦副的润滑特性,提出采用电液单元对润滑油膜进行主、被动控制的专用试验系统原理。论述该试验系统用油膜厚度反馈控制配流副密封间隙的模拟试验装置的原理与构成,将微缝隙流对电液控制系统的作用简化为弹簧中阻尼器负载,建立配流副对润滑油膜厚度的阀控缸物理模型并推导精密缸位移控制方程,分析影响润滑性能的主控参量及相互关系,仿真研究油膜厚度控制的动态特性。运用该试验系统进行了初步的平面配流副油膜试验。研究表明,油膜平衡的仿真与试验基本一致,供油压力、摩擦转矩等对润滑油膜的形成影响较大。伺服比例阀的反馈控制原理使系统的油膜厚度动态反馈性能趋于稳定,但在供油压力斜坡变化时油膜厚度平衡值在设定范围内有一定变化。     

有限元数值模拟在静压轴承设计中的应用

采用有限元法，借助ANSYS软件和自编子程序计算出了一定载荷下静压轴承流场的速度分布、压力分布及油膜的承载能力，得出了该载荷下保持液体摩擦状态所需的油腔供油压力，并根据计算结果设计了静压轴承的供油系统，经实用和跟踪测试证明，该系统工作良好。     

Performance of Hydrostatic Textured Thrust Bearing with Supply Holes Operating with Non-Newtonian Lubricant

The present article proposes a technique to improve the performance of textured hydrostatic thrust bearings with the use of oil supply holes. The article provides a comparison between smooth and surface-textured hydrostatic thrust bearings. To get an accurate prediction of the caviation regime, the Jakobsson-Floberg-Olsson (JFO) mass conservation algorithm has been used instead of the Reynolds boundary conditions. It has been observed that surface texture results in a significant decrease in friction power loss along with an improvement in other performance parameters. The study also reveals that the location of the supply hole for the lubricant system significantly affects the bearing performance.     

密闭压力油罐补油性能研究

液压闭式回路的补油问题直接影响着闭式回路的性能,为了使系统工作可靠,一般采用动力补油的方法,在一定程度上能解决提高系统的性能,但是却增加了成本与系统的体积。为解决液压闭式回路在无动力情况下的补油问题,提出一种球式补油阀加密闭压力油罐的方案,并介绍了密闭压力油罐的结构与工作原理。经试验研究,在无动力的情况下,该方案完全可以很好的起到补油的作用,从而消除系统产生的爬行与噪音。还给出了密闭压力油罐在设计时需注意的一些问题与设计方法,从而为其设计给出了理论依据。