胶乳分离机传动系统磨损状态的油样分析

分析了胶乳分离机传动系统中主要摩擦副的工作条件,采用铁谱和光谱分析技术对齿轮箱油样的磨粒浓度、磨粒特征及其成分进行了较系统的研究.结果表明,油样中磨粒浓度大,以细小尺寸的正常磨损磨粒为主,并含有相当数量的异常磨粒,磨粒主要来自铜基齿轮和下轴承,磨粒浓度的增幅、异常磨粒的出现率与机器工况、振动值及润滑有直接关系,铁谱与光谱分析结果有良好的吻合性.本研究对考察铜基齿轮材质、铸造工艺以及分离机的设计、制造和维护具有指导意义.     

基于在线铁谱图像的磨损机理智能辨识

基于状态的维护(Condition based maintenance,CBM)理念为机器健康状态维护提出了实时监测的新挑战。现有研究由于缺乏在线信息获取手段,磨损状态监测逐渐成为CBM的技术瓶颈。基于特征磨粒的磨损机理判断方法已经被广泛应用在离线磨损分析中,但是在线磨损机理的表征依然是一个很大的问题。针对基于在线铁谱图像的磨损机理开展研究。为了在一副在线铁谱图像中获得分离的磨粒图像,研究磨粒在在线铁谱传感器中的沉积机理。研究结果表明,磨粒链是图像中的主要形态,这是由于先前沉积的磨粒产生的局部磁场所致。设计一种依靠自适应调节沉积时间的在线磨粒沉积方法。运用该方法可以在在线铁谱图像中获得分离的磨粒,为特征磨粒的特征辨识提供了便利。参考分析铁谱知识,提取特征磨粒的4种形态学特征(当量尺寸、长径比、形状因子和分形维数)以综合表征4种典型磨损机理,包括正常、切削、疲劳、严重滑动磨损。采用反馈式人工神经网络构建自动磨损机理辨识模型。采用离线铁谱图像样本验证所建模型,结果表明该模型可以识别在线磨粒图像中的特征磨粒。对在线磨损机理表征方法进行了有意义的探索,所得研究成果将为在线磨损状态表征提供可行方法。     

铁谱技术在判断发动机磨损状态中的应用研究

发动机中各摩擦副的工作环境恶劣,磨拟状态复杂,很难精确描述。而发动机所处的磨损状态是判断其是否正常工作的重要标准,因此建立发动机磨损状态监测具有重大的经济和社会效益。笔者利用铁谱技术作为一种监测手段,通过磨粒分析来判断发动机的磨损状态。     

重型车辆齿轮油污染度和铁谱磨粒含量的关联分析

利用灰色关联分析方法对重型车辆变速箱齿轮油油样监测实验数据进行了分析,探讨了铁谱磨粒浓度和油液污染度之间的关联性.结果表明:重型车辆的齿轮传动系中,铁系颗粒的磨粒含量和大磨粒含量与油液污染度的关联性较强,可利用铁谱磨粒含量的变化趋势来估算润滑油的污染度等级.     

炼化设备油液分析诊断软件开发

介绍炼化设备油液分析诊断软件,该软件由铁谱定量分析模块、自动铁谱显微图像分析模块、油液分析数据库模块、磨损状态评判模块和诊断报告输出模块组成,通过铁谱分析仪、铁谱显微镜获取油样磨损信息,监测大型炼化设备润滑油品质量,并对磨损状况智能分级,为设备维护和管理提供依据。     

铁谱技术中非铁磁性磨损颗粒的监测研究

在使用铁谱技术进行机械工况监测过程中，由于铁谱仪的磁场很难收集到摩擦副产生的非铁磁性磨损颗粒，往往会导致监测结果产生偏差或不正确。以钢一铜试件对磨后获得的油样为例进行铁谱对比实验，研究了磁流体在非铁磁性磨粒监测方面的应用。结果表明，在磁流体的作用下，油液中的非铁磁性磨粒将被磁化而有效沉积到铁谱片上，从而使油液的监测分析结果更为全面和准确。此外，介绍了磁流体的组成，分析了磁流体使非铁磁性磨粒磁化的机理。     

基于反相灰度图二值化修正的铁谱图像磨粒特征提取

为准确获取铁谱图像中磨粒几何形状和特征参数,提出一种图像处理算法并对其进行验证。针对铁谱图像底色特征及磨粒特征提取精度要求,提出基于反相操作的铁谱图像灰度图转化方案,得到边缘清晰的铁谱灰度图;提出一种三段式阈值分割方案,利用腐蚀和膨胀操作解决二值化对铁谱图像有效磨粒区域的影响,讨论油污等干扰因素的消除策略;确定磨粒特征参数及磨粒识别方案,完成标准的正常滑动磨损图像处理和某实际的齿轮箱磨粒铁谱图像处理验证。结果表明:所提出的算法能够准确提取铁谱图像中磨粒所在区域的几何特征,通过磨粒标定计算得到了8个特征参数值,证明齿轮箱正处于滑动磨损状态。     

基于磨粒特征的矿用减速器磨损状态在线监测方法研究

为实现在线磨损状态监测技术在矿用减速器的工程应用,进行了在线铁谱磨粒特征与减速器磨损状态的映射关系的研究。首先,利用在线铁谱图像自动采集系统获取磨粒图像。进而利用数字图像处理技术获取磨损颗粒信息,主要包括:采用Otsu's自动阈值分割法将目标磨粒从图像背景中分离出来;通过像素扫描和边缘检测等方法提取磨粒的相对浓度和最大宽度尺寸信息。最后,获取设备运行过程中磨粒的统计学特征在时间序列上的变化趋势,实现矿用减速器的磨损状态在线分析。所提出的方法通过在线磨损的工程试验结果进行了有效性验证,为矿用设备的自动化监测与智能维护提供了新的技术手段。     

基于铁谱技术的内燃机的应用研究

介绍了内燃机的磨损及典型磨粒特点,利用铁谱技术作为一种监测手段,通过磨粒分析来判断内燃机的磨损状态.     

金属切削过程中的刀具磨料磨损研究

为了研究切削过程中刀具的磨料磨损,通过热等静压技术分别制作了Al_2O_3含量为0%、0. 5%、1%和2%的珠光体钢工件,然后用同种刀具切削这些工件。通过扫描电镜观察实验后的刀具和磨屑,并加以分析,得到以下结论:刀具的后刀面磨损随着磨粒含量的增加而明显增大,而刀具的前刀面磨损会随磨粒含量的增加有微弱的减小。温度增加会使刀具磨损增加;金属切削过程中磨料磨损率在初始阶段较高,但随着切削时间的增加会明显降低。     

On the wear and failure of high speed roller bearings

A laboratory bearing test rig was constructed to study wear and failure mechanisms in high speed roller bearings under different conditions of loading and lubrication. The design of the rig permitted three bearings to be tested simultaneously. A test run of 720 h duration was performed during which wear of the bearings was monitored using ferrography and atomic absorption oil analysis. Wear debris particles collected from the bearings by ferrography were studied with scanning electron microscopy using energy-dispersive X-ray analysis. The results of ferrography were correlated with the metallographic observations made on the worn bearings.It was found that for lightly loaded high speed roller bearings rolling contact fatigue including surface pitting is not a significant wear or failure mechanism. However, misalignment due to shaft deflection above a critical point cannot be tolerated. Wear of high speed engine bearings can successfully be monitored by ferrography but, as the wear condition accelerates, frequent oil sample collections are beneficial.     

齿轮磨损状态的在线铁谱监测试验研究

对ＯＬＦ１在线铁谱仪用于齿轮磨损状态的监测进行了研究。试验数据分析表明，ＯＬＦ－１在线铁谱仪对大磨粒有很强的敏感性，其采样值的大小和变化反映了齿面状态的变化。在正常磨损情况下，采样值曲线比较平稳；而一旦采样值出现无规律波动，则意味着不正常磨损的开始。与分析铁谱仪数据对比，也显示出非常近似的变化趋势。因而，ＯＬＦ－１在线铁谱仪用于齿轮磨损状态的实时和连续监测具有良好的性能。本文同时指出，ＯＬＦ－１在线铁谱与其它油液分析技术相结合，可以更准确地进行齿轮磨损状态的监测和诊断     

Condition monitoring of steam turbine-generator through contamination analysis of used lubricating oil

The objective of this paper is to present a systematic analysis of wear particles contained in used lubricant of steam turbine-generator of a thermal power station. The turbogenerator was condition-monitored over a period of two years through wear debris and particulate contamination analysis of the oil. Various sophisticated techniques such as automatic particle counter, ferrography, inductively coupled plasma atomic emission spectrometry (ICPAES), scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDAX) have been employed to extract the relevant information about the health of the machine. Eventually, a correlation of different techniques of wear debris monitoring on the basis of current investigation ascertains the significance of the collective approach of various techniques to avoid catastrophic breakdowns and expensive component replacements.     

The use of ferrography and spectrographic oil analysis to monitor the performances of three 90 kW gearboxes

An account is given of the monitoring of the condition of three 90 kW gearboxes tested at the National Coal Board's Mining Research and Development Establishment. The techniques used were ferrography and spectrographic oil analysis. The gearboxes were tested primarily to examine the effect of two types-of loading on life and the monitoring techniques were applied to assess their usefulness within the laboratory with machinery having a high level of contamination by wear particles. Four failures occurred during the running of the three gearboxes and of these all were detected by spectrographic oil analysis, but only three were detected by ferrography. The discussion of the results includes comments on their analysis and on the basis on which failure is predicted.     

油液污染度分析在船用舵桨装置状态监测中的应用

应用污染度检测仪对2条港口作业拖船的舵浆装置润滑油进行了污染度检测,通过对所测污染度数据的分析并辅以油液光谱分析和铁谱分析,对船用舵桨装置运动副的磨损状态及发展趋势进行了评价和预测。指出油液污染度分析不仅可对机械设备的磨损状态进行监测、评价和趋势预报,而且简单方便可行,是设备状态监测与故障诊断的一种重要技术手段。     

Advances in quantitative analytical ferrography and the evaluation of a high gradient magnetic separator for the study of diesel engine wear

Several sources of variation in quantitative analytical ferrography are investigated. A standard ferrography analysis procedure is developed. Normalization of ferrographic data to account for the amount of oil used to make the Ferrograms is discussed. Procedures to minimize the errors involved in calculating three quantitative ferrography parameters, i.e. the area A_L (% (ml of oil)⁻¹) covered by the large particles, the area A_S (% (ml of oil)⁻¹) covered by the small particles and the area under the curve (millimeters per cent per milliliter of oil) are outlined. Ferrographic data are presented which show that the volume and dilution ratio of the oil sample being analyzed have a major effect on the accuracy of the analysis. Several variables which influence the area-covered readings of the particle deposit on a Ferrogram are discussed. The accuracy of quantitative analytical ferrography is assessed.

Quantitative analytical ferrography is used to evaluate a high gradient magnetic separator (HGMS), both as a tool for engine wear research and as an oil filter. Laboratory tests indicate that the HGMS is an order of magnitude more efficient than conventional paper oil filters in removing magnetic wear debris from the lubricating oil.     

Application of magnetization measurements to wear debris analysis

Spectrometric oil analysis for total wear metal amounts is often used to monitor lubricated machinery. In many cases iron is the dominant wear metal, and spectrometric analysis gives good results for total iron. However, iron may be present in several forms such as metal particles, oxides, carbides, sulfates and dissolved ions. A breakdown of total iron into the amounts and forms of iron present should give further valuable insight into wear phenomena taking place inside the machine.In this paper the use of magnetization measurements on samples of used oils and oil filters to obtain information on the forms of iron present in wear debris from lubricated machines is introduced. The measurement technique is described and the magnetic properties of some iron species that might be expected in wear debris are reviewed. This technique provides information on both ferromagnetic and paramagnetic species through the observation of various magnetic properties. Several illustrative examples are included. The ability of this technique to detect the paramagnetic as well as the ferromagnetic components is important because it is often found that the majority of the iron in wear debris is paramagnetic. A correspondence between the measured ferromagnetic component and ferrography is also shown for some cases.     

Correlation between the tribological behaviour and wear particle morphology—case of grey cast iron 250 versus Graphite and PTFE

Wear particles are produced as a result of interaction of two surfaces in mechanical systems. After extracting and separating particles by different techniques (filtration, ferrography …), their morphology, which is a function of the condition of tribological system (tribosystem), can be related directly to the wear process. In order to understand wear mechanisms, it is interesting to study the relationship between the characterization of wear particles (aspect ratio, shape factor, spike parameter) and the mechanical factors of wear. Therefore, a series of tests were conducted with polytetrafluoroethylene (PTFE) versus cast iron, and flake graphite versus cast iron. Wear particles were studied in a particular tribosystem to understand debris formation and wear. Consequently, after friction tests according to a plane on plane contact, wear particles were collected. After separation tests, particle morphology obtained through image analysis techniques, was used to determine how debris are produced and to elucidate wear mechanisms. Finally, we propose a wear mechanism with these particular tribosystems.