单色光干涉面接触润滑膜厚在线测量

提出了滑块-玻璃盘形成的面接触润滑油膜厚度光干涉在线测量方法。以单色激光为光源,根据油膜厚度变化引起平行干涉条纹平移的物理特征,基于光流和动态时间规整技术构造复合算法,测量干涉图像相邻帧空间域上一维光强曲线的位移,从而得到相邻帧之间的油膜厚度差。从零速度开始记录每一帧干涉图像对应的膜厚变化,实时计算出当前帧对应的膜厚,实现了膜厚的在线测量。当前算法的测量结果与离线膜厚测量结果进行了对比,验证了该系统的测量准确性。进行了阶跃载荷、匀加速及匀减速工况下的膜厚测量,揭示了膜厚变化规律。     

用冲击脉冲法测量轴承油膜厚度

介绍了在油膜厚度测试台上用瑞典SPM公司的BAS-10型轴承分析仪器对航海陀螺仪用精密球轴承C106018A_2之外沟与钢球接触点油膜厚度的测量原理和测量方法。对影响轴承油膜厚度的相关因素进行了试验分析,得出了相应的膜厚状态曲线。结果表明,用冲击脉冲法测量轴承油膜厚度是一种非常灵敏、有效和可靠的方法,测量精度可达到0.025μm。附图6幅,表2个。     

线性/非线性时间序列模型在推力轴承油膜厚度测量中的应用

通过对推力轴承油膜厚度特征量的采集、提取。利用GNAR模型对数据进行拟合并和实际测量值进行比对,较小的误差验证了非线性时间序列模型GNAR适用于轴承油膜厚度的状态识别和动态预测,并在时序图上发现轴承油膜厚度与轴承转速和轴承所受载荷存在密切的关系。     

推力轴承模型试验件承载能力的实验

将一透平机械中的中型推力轴承通过相似模型化得到模型试验小型轴承,对其承载能力进行了实验,得到了轴瓦的进、出油温度和支点处的油膜厚度。实验表明,可用支点处的油膜厚度来代替最小油膜厚度的测量,为工程实际提供了一种新的测量思路     

面接触油膜润滑测量系统

介绍了一种能够实现面接触油膜润滑测量的试验系统,该系统以静止的刚性滑块和旋转的透明玻璃盘组成润滑副。滑块的定位采用柔性并联机构,可进行面接触倾角的微小调节。油膜厚度测量采用多光束干涉技术。照明采用激光外部同轴照明,可有效扩大图像视场和膜厚的测量范围。利用该系统测量了恒倾角面接触薄膜润滑的膜厚特性和摩擦力特性,结果与已有理论有较好的一致性。     

高速轧辊磨头油膜轴承的设计及其润滑技术研究

为了实现高速轧辊磨床的国产化,通过对比分析普通轧辊磨头油膜轴承与高速轧辊磨头油膜轴承在设计及其润滑技术上的异同,设计出一种适合于高速轧辊磨头的新型油膜轴承,该油膜轴承具有油膜均化作用强,散热性能好以及油膜刚度好等优点.在此基础上,对该高速轧辊磨头油膜轴承的润滑技术进行研究,并设计出此油膜轴承的润滑供油系统.     

偏心圆凸轮油膜润滑测试系统

为准确测量凸轮-挺杆接触的油膜厚度,设计制造凸轮-挺杆润滑油膜光干涉测量系统。该系统采用偏心球-玻璃盘接触副模拟凸轮-平底挺杆的点接触,通过同步带轮带动偏心球转动,实现偏心球运动过程中摩擦力、载荷的测量,同时通过双色光干涉技术对偏心圆凸轮-挺杆接触的油膜厚度进行测量。使用该系统对不同条件下偏心圆凸轮-挺杆机构油膜厚度、摩擦力进行测量,测量结果表明:载荷越大,油膜厚度越小;转速越高,膜厚越大,"鼻尖"处的惯性力越大;相同工况下,偏心距较大时,在区间0°～90°、270°～360°膜厚较高,在90°～270°区间膜厚略低;随转速的增大摩擦力最大值所在的位置前移。     

基于光强反射式光纤传感器法的推力轴承瓦油膜厚度测量研究

综述推力轴承油膜厚度的测试方法及理论。在推力轴承油膜厚度的测量研究领域中,光纤传感技术在目前已经成为一种较先进的方法,阐述在此技术基础上研制的油膜厚度测量系统。     

滚动轴承弹流油膜测试仪的研制与应用

利用阻容振荡原理,通过电路参数优化,研制出一台滚动轴承弹流油膜厚度测试仪。仪器的分辨率为３．５Ｈｚ／ｐＦ,测量范围为０￣２．２ｎＦ。仪器在全膜弹流润滑时可定量测量弹流膜厚;在部分膜时可根据振荡波形分析非金属时间接触率。利用仪器实测某惯性轮轴承的弹流油膜厚度,并考虑热和乏油的影响,对轴承的弹流油膜厚度进行理论计算,实测结果与理论计算结果基本一致。     

润滑油膜光干涉测量系统与技术研究进展

光干涉是润滑油膜厚度测量中最广泛采用的手段,干涉图像的光强与色度学信息反映出接触区内部油膜的厚度与形状。概述光干涉技术在油膜测量领域的发展历程,介绍比色法、光谱分析法、相对光强法等3种典型的光干涉油膜测量方法和新发展的双色光光强调制测量方案。阐述润滑油膜测量光干涉测量系统的理论建模方法和系统设计的关键,并展望光干涉油膜测量系统的发展方向,如开发专用的光干涉油膜测量仪器,实现多光源的同步测量等。     

Application of Ultrasonic Sensing to Monitoring Lubrication Conditions in a Refrigeration Compressor

Understanding lubrication conditions in a refrigeration compressor is valuable for machine design and ensures the reliability of air conditioners. In this work, the lubrication conditions of a journal bearing in a scroll compressor were evaluated by applying ultrasonic sensing. An ultrasonic probe was attached to a journal bearing supporting a crank shaft in the compressor. The probe transmitted ultrasonic pulses toward the lubricant film between the shaft and the bearing and then received reflections. The lubricant film can be monitored by measuring the reflection amplitude of the ultrasound, which increases with the thickness of the thin lubricant film. With the whirling shaft in the bearing, the minimum reflection amplitude was measured as an index of the minimum lubricant film thickness in the bearing during stable and transient operations of the compressor. Then the measured reflection amplitude was compared with the Sommerfeld number, which is also known to increase with lubricant film thickness. The measured minimum reflection amplitude mostly changed in trend similar to that of the Sommerfeld number. However, the measured minimum reflection amplitude behaved differently during the first 400 s in the startup process. An observation of the lubricant reservoir showed generation of small bubbles in the lubricant in the period. Overall, test results support the usability of the ultrasonic measurement to trend monitoring of the lubricant film thickness in the journal bearing in the compressor. The existence of bubbles in the journal bearing was indicated by the results of the ultrasonic measurement and observation.     

基于超声波的液体滑动轴承润滑油厚度的测定

在深入研究超声波脉冲反射式测厚原理的基础上,构建了一套完整的液体滑动轴承润滑油膜厚度的超声波在线检测系统,并进行了详细的分析和简易实验,实验数据与理论数据基本吻合。     

Effect of wear of bearing surfaces on elastohydrodynamic lubrication of metal-on-metal hip implants

The effect of geometry change of the bearing surfaces owing to wear on the elastohydrodynamic lubrication (EHL) of metal-on-metal (MOM) hip bearings has been investigated theoretically in the present study. A particular MOM Metasul bearing (Zimmer GmbH) was considered, and was tested in a hip simulator using diluted bovine serum. The geometry of the worn bearing surface was measured using a coordinate measuring machine (CMM) and was modelled theoretically on the assumption of spherical geometries determined from the maximum linear wear depth and the angle of the worn region. Both the CMM measurement and the theoretical calculation were directly incorporated into the elastohydrodynamic lubrication analysis. It was found that the geometry of the original machined bearing surfaces, particularly of the femoral head with its out-of-roundness, could lead to a large reduction in the predicted lubricant film thickness and an increase in pressure. However, these non-spherical deviations can be expected to be smoothed out quickly during the initial running-in period. For a given worn bearing surface, the predicted lubricant film thickness and pressure distribution, based on CMM measurement, were found to be in good overall agreement with those obtained with the theoretical model based on the maximum linear wear depth and the angle of the worn region. The gradual increase in linear wear during the running-in period resulted in an improvement in the conformity and consequently an increase in the predicted lubricant film thickness and a decrease in the pressure. For the Metasul bearing tested in an AMTI hip simulator, a maximum total linear wear depth of approximately 13 microm was measured after 1 million cycles and remained unchanged up to 5 million cycles. This resulted in a threefold increase in the predicted average lubricant film thickness. Consequently, it was possible for the Metasul bearing to achieve a fluid film lubrication regime during this period, and this was consistent with the minimal wear observed between 1 and 5 million cycles. However, under adverse in vivo conditions associated with start-up and stopping and depleted lubrication, wear of the bearing surfaces can still occur. An increase in the wear depth beyond a certain limit was shown to lead to the constriction of the lubricant film around the edge of the contact conjunction and consequently to a decrease in the lubricant film thickness. Continuous cycles of a running-in wear period followed by a steady state wear period may be inevitable in MOM hip implants. This highlights the importance of minimizing the wear in these devices during the initial running-in period, particularly from design and manufacturing points of view.     

基于推力轴承结构的润滑膜厚与摩擦因数测量系统

开发一种基于推力轴承结构的润滑膜厚与摩擦因数测量系统。该测量系统在较低速度下可实现膜厚与摩擦因数的同步测量，在较高速度下可通过保持架固定和玻璃盘回转模式实现润滑油膜测量，通过保持架自由回转和玻璃盘固定模式实现摩擦因数的测量。通过测量不同载荷下的润滑油膜厚度随速度变化曲线，以及与单点接触的测量结果进行定量对比，验证了该测量系统的可靠性。测量得到的摩擦因数曲线表明了滚动体打滑现象的存在。该测量装置为润滑剂特性和滚动轴承润滑特性研究提供了一种评价方法。     

基于FRAP的微间隙润滑油膜流速测量方法

薄油膜润滑广泛存在于各类精密机械与微机电系统中。微纳米间隙内的润滑油流动是影响薄膜润滑承载力的重要因素,但目前薄润滑油膜的流速测量仍然缺少有效手段。本文基于荧光漂白恢复显微技术和漂白区域形状演化过程的成像分析,建立了油膜流速测量系统,可以对微米间隙润滑油膜的速度分布进行原位测量。利用建立的系统获得了厚度为8μm时聚丁烯PB450润滑油膜的库埃特流速分布。重建的荧光漂白强度分布曲线和实验测量结果的皮尔森相关系数大于0.95,且流速分布符合已有润滑理论,证明了测量结果的可靠性。     

润滑油膜厚度光纤检测系统的智能化设计

在研究应用光纤位移传感器原理检测润滑油膜厚度状态技术的基础上，组建了一套完整的智能在线检测系统并对其进行了标定和运行实验。实验结果表明：所设计的测量系统不仅切实可行且反应灵敏、检测效果良好；所研制的信号采集电路及其与上位机串行通讯运行平稳可靠、反应迅速及时且精度高;开发的数据处理程序和虚拟仪器用户界面操作简便、运行状态良好;该测试系统能够应用到润滑油膜厚度的状态监测中,且具有鲜明的智能化特性。     

In Situ Raman Microspectrometry of Lubricated Tribologic Contacts. Part Two: Simultaneous Measurements of Pressure,Lubricant Film Thickness and Temperature Distributions in a Running EHD Contact

Raman micro-spectrometry is used to acquire point spectra in a running EHL contact. The quantitative method developed in part one of this study, measuring the lubricant film thickness, is complemented by a data treatment yielding quantitative values of the pressure and temperature in the lubricant. The comparison between experimentally measured pressure and film thickness distributions and numerical calculations shows an excellent quantitative agreement. The simultaneous quantitative measurement of pressure, film thickness and temperature distribution carried under pure rolling afforded a direct and quantitative correlation between the three parameters.     

流体动压润滑油膜厚度及油池的荧光测量

基于面接触润滑油膜厚度荧光测量系统,研究润滑油中荧光剂强度与剪应变率的关系,筛选得到适合油膜厚度测量的润滑油和荧光剂的组合,并研究荧光强度和油膜厚度之间的关系。结果表明:R6G荧光剂和PEG400润滑油组合与Coumarin6荧光剂和PAO8润滑油组合的荧光强度不受剪应变率影响,可用于油膜厚度的荧光测量;荧光强度和油膜厚度存在单值线性关系,通过测量荧光强度可以求解油膜厚度。建立接触区周围油膜厚度及油池分布的测量方法,研究载荷和速度对油膜厚度以及接触区周围润滑剂的迁移特性的影响。结果表明:油膜厚度随速度增加而增加,随载荷增加而减小;随着速度增加,滑块入口处油池产生润滑剂堆积,出口处油池出现双侧脊分离,两侧面油池无明显变化;油池的变化是表面力、机械分离力和离心力综合作用的结果。     

Monochromatic image analysis of elastohydrodynamic lubrication film thickness by fringe intensity computation

Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by image processing method for the images from an optical interferometer with monochromatic incident light. Interference between the reflected lights both on half mirrorCr coating of glass disk and on super finished ball makes circular fringes depending on the contact conditions such as sliding velocity, applied load, viscosity-pressure characteristics and viscosity of lubricant under ambient pressure. In this situation the film thickness is regarded as the difference of optical paths between those reflected lights, which make dark and bright fringes with monochromatic incident light. The film thickness is computed by numbering the dark and bright fringe orders and the intensity (gray scale image) in each fringe regime is mapped to the corresponding film thickness. In this work, we developed a measuring technique for EHL film thickness by dividing the image patterns into two typical types under the condition of monochromatic incident light. During the image processing, the captured image is converted into digitally formatted data over the contact area without any loss of the image information of interferogram and it is also interpreted with consistency regardless of the observer’ s experimental experience. It is expected that the developed image processing method will provide a valuable basis to develop the image processing technique for color fringes, which is generally used for the measurement of relatively thin films in higher resolution.