机械设备摩擦磨损标准铁谱图谱分析技术研究

针对铁谱分析图谱识别与诊断困难的问题,运用长期积累的知识和铁谱图,根据机械设备摩擦磨损的规律、形式与磨损程度,对铁谱图形进行分类分级,形成了正常、切削、滑动、疲劳和复合五大磨损磨粒。对各类磨损磨粒进行分级,定义各类各级铁谱磨粒的特征,形成了标准铁谱分析图,为铁谱图的可靠分析提供重要的参考。     

基于灰靶理论和磨粒浓度的磨损状态自动识别

利用图像分割算法可得到铁谱图像上按尺寸分布的各个级别的磨粒浓度,但如何据此对磨损状态进行自动识别是自动化铁谱分析的难点。将灰靶理论引入到磨损状态自动识别中,依据图像各尺寸的磨粒浓度建立模式序列,并从模式序列中构造标准模式;然后计算出贡献度加权值,并将贡献度权值引入靶心度的计算;再通过靶心度和设备磨损状态的分级,实现对设备磨损状态的自动识别。     

基于铁谱分析技术的齿轮磨损研究

齿轮副的磨粒本身携带相当丰富的信息,根据磨粒的识别特征可以判断齿轮副处于何种磨损方式和磨损程度.提出了基于铁谱分析技术的齿轮磨损分析方法,对某铁路机车车轴齿轮箱润滑油样进行了铁谱分析,探讨了该齿轮的磨损阶段和磨损机制,提出了齿轮箱的合理使用措施.     

铁谱定量技术研究

在机器工作过程中,润滑油中磨损颗粒含量、组成、尺寸、粒度分布是一动态系统。在正常磨损期内,磨损速率维持在自身的一个平衡点附近,一旦磨损出现异常,将打破磨损过程的动态平衡,向失稳方向发展。 油样铁谱分析是目前使用最广泛最有发展前途的油润零件无损检验手段,它可在机     

铁谱分析技术在发动机早期磨损检测中的应用

介绍了利用铁谱分析技术对工作一段时间后的发动机润滑油用磁性方法把混于其中的铁质磨粉分离出来,并按其尺寸大小依次、不重叠地沉淀到一块透明的基片上,以进行定性分析的应用方法。对发动机的早期磨损进行随时检测,及时发现问题,解决问题。保证汽车发动机在磨合期的早期磨损中尽量减少非正常磨损。     

铁谱分析技术在石化行业的应用及前景展望

论述了铁谱分析技术在国内外各行业的研究和应用现状及其在石化行业的应用前景,讨论了铁谱分析技术应用的最新进展,认为铁谱分析技术的研究热点是建立摩擦学系统的铁谱磨损数学模型、多种油液监测技术综合使用、磨粒自动识别技术和新型在线铁谱仪研制与开发。根据分析论证,认为铁谱技术可以为石油化工设备的安、稳、长、满、优运行提供有力的保障。     

铁谱分析技术必须向前跨一步

铁谱分析技术的发展自70年代初以来,已有20多个年头,在机械失效分析方面做了不少工作,在工况监测和机械的失效预报方面也积累了不少经验,但同时也暴露出传统铁谱分析技术存在的根本性问题,使得铁谱分析技术无法进一步发展和在工业界真正推广使用.1.铁谱分析技术作为机械失效预报的依据是什么?一般认为,磨屑是磨损的直接产物,磨屑带来了磨损工况或机械运转工况的信息.问题在于除了正常、异常信息外,是否可以提供机械磨损的具体有效信息?或曰根据油内磨屑的状况能否给出机械设备失效预报方面的正确提示?笔者以为传统铁谱技术并未能回答这些问题,当然影响了该技术的真正推广使用.这有理论上的原因和使用工具——铁谱仪本身缺点的原因.     

煤矿提升机滑动轴承的磨损失效分析

运用油液分析和铁谱分析技术手段,探讨了煤矿提升机滑动轴承的磨损失效机制,分析了巴氏合金摩擦聚合物的成因、结构与形貌特征;讨论了提升机滑动轴承的润滑方式和润滑油的选择.滑动轴承巴氏合金轴承衬偶合副磨损失效的主要形式是粘着磨损,巴氏合金轴承衬产生的磨屑是以巴氏合金为载体和粘和剂的多种材料成分的微粒共存的聚合物,在对提升机滑动轴承进行润滑磨损状态监测时,要同时分析巴氏合金摩擦聚合物的尺寸及其在润滑油中的含量.     

因子分析理论在重型车辆油液分析及状态监测中的应用

对某重型车辆动力系统的润滑油进行光谱分析和PQ分析,利用因子分析原理提取润滑油液中表征磨损信息的主要因子,运用统计学原理得出该车辆监测诊断标准的关键运行状态分界点,研究其磨损状况。该方法分析结果与铁谱分析结果一致,为了解和判断该车辆的磨损可靠性情况提供了依据。     

一种航空发动机磨损故障模糊融合诊断方法

为提高航空发动机滚动轴承的磨损故障诊断的精度,综合利用多种油液分析方法的优点,提出一种航空发动机磨损故障的模糊融合诊断方法.首先,针对光谱分析、铁谱分析、颗粒计数分析、理化分析数据的各自特点,基于自定义隶属度函数对油液分析数据进行模糊化处理,从而得到表征光谱分析、铁谱分析、颗粒计数分析、理化分析数据的证据可信度和规则可...     

钢质齿轮副在微纳米混合磨合油中的磨合试验研究

将微米和纳米固体粉末单独或混合加入到68#机械油中,配制了5种微米、纳米或微纳米混合磨合油,并试验研究了5种磨合油分别应用于钢质粗糙软齿轮副间的磨合磨损行为和作用机制。研究结果表明:当混合磨合油中微米颗粒粒度比齿面三维粗糙度Sa值小时,磨粒磨损并不显著,且纳米微粒起到加剧磨合磨损的作用。当混合磨合油中微米颗粒粒度比齿面三维粗糙度Sa值大时,磨粒磨损显著,但纳米微粒起到缓和磨合磨损的作用。齿面三维形貌表明纳米颗粒对齿轮副表面有填充作用,对磨合后齿面形貌的结构有较大影响。磨合试验中还发现了因齿面副两表面磨损率差形成的负电阻现象。     

齿轮点蚀破坏中磨损与振动关系的试验研究

利用铁谱分析技术和振动分析技术中的时频分析方法研究了模拟点蚀故障齿轮磨损与振动的关系。分析结果表明点蚀齿轮磨损和4个时域特征值从一面一点、一面三点到多面多点依次变大,多面多点蚀齿轮磨损严重,磨粒数量最多;点蚀齿轮出现以输入输出端的啮合频率为中心,以转频为调制频率的边频带。齿轮磨损与振动相互关联,磨损量的变化率与振动方差变化率在3种点蚀齿轮中表现明显;但磨损量的增长率不仅与齿面点蚀的程度有关,还与点蚀的齿数有关;而齿轮的振动强度与齿轮齿面点蚀的程度最相关,即齿面点蚀破坏越厉害,振动越剧烈。     

Automated classification of wear particles based on their surface texture and shape features

In this study, the automated classification system, developed previously by the authors, was used to classify wear particles. Three kinds of wear particles, fatigue, abrasive and adhesive, were classified. The fatigue wear particles were generated using an FZG back-to-back gear test rig. A pin-on-disk tribometer was used to generate the abrasive and adhesive wear particles. Scanning electron microscope (SEM) images of wear particles were acquired, forming a database for further analysis. The particle images were divided into three groups or classes, each class representing a different wear mechanism. Each particle class was first examined visually. Next, area, perimeter, convexity and elongation parameters were determined for each class using image analysis software and the parameters were statistically analysed. Each particle class was then assessed using the automated classification system, based on particle surface texture. The results of the automated particle classification were compared to both the visual assessment of particle morphology and the numerical parameter values. The results showed that the texture-based classification system was a more efficient and accurate way of distinguishing between various wear particles than classification based on size and shape of wear particles. It seems that the texture-based classification method developed has great potential to become a very useful tool in the machine condition monitoring industry.     

Micropitting performance of nitrided steel gears lubricated with mineral and ester oils

This study compares the gear micropitting performance of high pressure nitriding (HPN) steel gears, lubricated with three different gear oils: a standard mineral lubricant, containing a special micropitting additive package, and two biodegradable esters with low toxicity additivation. The physical, chemical and wear properties of the three lubricants were determined, as well as their biodegradability and toxicity characteristics. The gear material and the corresponding heat treatment are presented.Gear simulation tests were performed in a Falex machine, using a roller-disc geometry, in order to evaluate the lubricant temperature and friction coefficient corresponding to each gear oil.Gear micropitting tests were performed on the FZG machine, using type C gears, and lubricant samples were collected during the tests for wear particle analysis. Post-test analysis included the mass loss measurement of the gear (pinion and wheel), the ferrometric analysis of the lubricant samples and the teeth flank roughness measurement below and above the pitch line. The teeth flanks were inspected using scanning electron microscopy (SEM) and surface topography measurements to assess the number and depth of micropits. Metallurgical cuts were done to observe the size and depth of micropits as well as contact fatigue crack initiation and propagation.The ester lubricants show better micropitting performance than the mineral oil, confirming the potential of environmental friendly fluids as high-performance gear oils.     

The Slow-Speed Wear Behavior of Case-Carburized Gears Lubricated with NLGI 00 Grease under Boundary Lubrication Conditions

NLGI 00 greases are often used to lubricate gears running at low pitch line velocities, such as, for example, in large open gear drives. At low pitch line velocities, sliding wear, which under these operating conditions is referred to as slow speed wear, is often the limiting factor to gear lifetime. A thorough knowledge of the effect of different grease components on the wear behavior is therefore important when selecting a grease to effectively reduce gear wear in a given gear drive. In order to systematically investigate and analyze the influence of different grease components on the slow-speed wear behavior of case-carburized gears, systematic gear tests using the Gear Research Center's (FZG) back-to-back gear test rig were conducted. Primarily, the focus of the experimental investigations is on the influence of the base oil viscosity and type, the additive type, and also the type of soap thickener on the gear wear behavior at low pitch line velocities. To experimentally determine the influence of these different grease components on the wear behavior of case-carburized gears, a modified, more stringent wear test, based on the standard DGMK slow-speed wear test for gear oils, was developed. Different NLGI 00 greases with base oil viscosities between ν₄₀ = 70 and 1,200 mm²/s were investigated.

Base oil type and base oil viscosity were shown to have only a minor effect on the wear behavior under boundary lubrication conditions. On the other hand, the thickener type and especially the additive type play an important role in determining the wear behavior.     

Effect of sursulf treatment on fatigue life of medium carbon steel spur gears

Medium carbon steel gears untreated as well as Sursulf treated were tested in a back-to-back gear test rig. The failure of the test gears was by pitting. The contact stress-pitting life curves have been established for both untreated and Sursulf treated conditions. Sursulf treated gears exhibited low wear compared to untreated. Wear particle analysis of lubricating oil was carried out to analyse the nature of failure. Cumulative wear particle concentration at pitting limit has been suggested as a basis for predicting the onset of the failure in the gears.     

带式啮合介质齿轮传动的磨损仿真分析

带式啮合介质齿轮传动中,齿轮副的接触由高模量的齿轮对接触转化为高模量齿轮与低模量介质带的接触,磨损主要发生在柔性介质带上。应用Archard黏着磨损理论,建立带式啮合介质齿轮传动磨损数学模型,用Solid Works三维建模软件建立带式啮合介质齿轮的实体模型,并对其结构静力学进行分析;根据磨损数学模型和接触应力的分布情况,模拟计算出介质带的磨损量。结果表明:带式啮合介质齿轮传动最大接触应力发生在啮合节点处,弹性应变主要发生在介质带上,啮合节点处应变值最大;介质带的磨损量随载荷和滑动距离的增加而增加,最大磨损量发生在啮合节点处,在齿轮啮合线上不同节点处磨损量略有差距,边缘处磨损量最大。     

齿轮全齿磨损的胞映射全局动力学分析

含故障齿轮非线性系统的全局性态分析是对齿轮正确故障诊断的状态依据,运用能够反映非线性系统复杂全局性态的简单胞映射方法,把故障齿轮非线性系统所处的状态空间转化为胞空间,对齿轮非线性系统在不同程度磨损故障状态下的动力系统的全局特性进行了分析,通过对比不同程度故障下系统的吸引域及其吸引胞,得到磨损故障齿轮非线性系统全局特性的变化规律,为齿轮非线性系统的故障诊断提供了另一种研究思路和方法。     

Polymer gear surface thermal wear and its performance prediction

This paper will concentrate on acetal gear wear behaviour and its performance prediction based on the extensive investigations on the gear thermal mechanical contact both experimentally and numerically. It has been found from the tests that acetal gear wear rate will be increased dramatically when the load reaches a critical value for a specific geometry and running speed. The gear surface will wear slowly with a low specific wear rate if the gear is loaded below the critical one. The possible reason of the sudden increase in wear rate is due to the gear operating temperature reaching the material melting point under the critical load condition. Gear surface temperature has been then investigated in details through three components: ambient, bulk and flash temperatures. Through extensive experimental investigations and modelling on gear surface temperature variations, a general relation has been built up between gear surface temperature and gear load capacity. An approach for acetal gear transition torque prediction has been proposed and this method is based on the link between polymer gear wear rate and its surface temperature. The method has been related to test results under different operating speeds and gear geometries. Good agreements have been achieved between the proposed method predictions and experimental test results.     

应用Hilbert-Huang变换的齿轮磨损故障诊断研究

提出了一种基于H ilbert-Huang变换的齿轮磨损故障诊断的新方法。H ilbert-Huang变换是先把时间序列信号,用经验模态分解方法分解成不同特征时间尺度的固有模态函数,然后经过H ilbert变换获得频谱的信号处理新方法。介绍了该方法的基本原理,并将H ilbert-Huang变换应用于齿轮箱中齿轮磨损故障诊断的研究,通过选取表征齿轮磨损故障的IM F分量进行边际谱和能量谱分析,就可提取齿轮故障振动信号的特征。齿轮故障实验信号的研究结果表明,H ilbert-Huang变换时频分析方法,能有效地诊断齿轮的磨损故障。