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对液压系统的常见故障及常用监测方法进行了分析,提出将静电传感器技术运用到液压系统在线监测中;研究了液压系统油液在线监测机理、磨粒荷电量的影响因素;设计了一套适用于液压系统的油液在线监测系统;研究了磨粒浓度、大小及材质与传感器测量电压之间的关系.运用静电传感器在线监测液压系统工作介质中磨损颗粒的荷电情况,得到液压系统磨损的监测结果,验证了静电监测方法在液压系统在线监测中的有效性与可行性. 相似文献
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滚动轴承性能退化静电监测方法及试验 总被引:2,自引:0,他引:2
采用静电方法对滚动轴承进行在线监测以及退化评估的研究。在滚动轴承寿命强化试验机平台上,使用自研磨损区域静电传感器对滚动轴承进行在线监测,通过多组试验采集得到滚动轴承磨损静电信号,在对滚动轴承磨损过程静电产生机理分析的基础上,进行静电信号的特征提取,通过加速疲劳全寿命周期试验进行滚动轴承性能退化评估,并与振动信号与温度信号进行对比验证。研究结果表明,磨损区域静电监测技术可以实现滚动轴承性能退化的在线监测,该研究是机械系统在线监测以及故障诊断和预测的重要组成部分,并为仪器实现产品化奠定了基础。 相似文献
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采用粉末冶金方法制备一种银-铜-石墨-碳纤维复合材料,利用环块式摩擦磨损试验机对该复合材料和黄铜滑环组成的摩擦副在大气条件下进行载流摩擦磨损试验,分析不同速度下载流大小对摩擦因数、接触表面电阻、接触表面电噪声、磨损量的影响。研究结果表明,摩擦因数、接触电阻、磨损量随载流的增大而增大,接触表面电噪声与电流呈非线性关系;该银基复合材料与黄铜滑环摩擦副的磨损机制在纯机械摩擦磨损条件下主要为黏着磨损,在载流条件下为磨粒磨损,电弧产生的电蚀促进了磨粒磨损的发生。该银基复合材料与黄铜滑环摩擦副的电噪声符合相关标准,具有较高的可靠性。 相似文献
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应用QG-700型高温气氛摩擦磨损试验机,研究了常温下CrNiMo钢/黄铜配副在不同氮/氧混合气氛比例条件下的干滑动摩擦磨损性能,利用扫描电子显微镜(SEM)、EDAX能谱仪(EDS)和X射线光电子能谱仪(XPS)分析其磨损机制。试验结果表明:随着氮/氧混合气氛中氧气气氛比例的增加,销试样磨损率和配副的摩擦因数整体均呈现降低趋势;磨损机制逐渐由黏着磨损和磨粒磨损向氧化磨损、磨粒磨损和黏着磨损共同作用机制转变;摩擦表面生成铁和铜的氧化物,且氧化物的成分随着氧气含量不同而有所不同。 相似文献
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Hongxia Ma 《Tribology International》2009,42(6):869-874
Polyelectrolyte multilayers (PEMs) were prepared on Si substrates by alternative deposition of poly(sodium 4-styrenesulfonate) (PSS) as polyanion and poly (diallyldimethylammonium chloride) (PDDA) as polycation. The PEM film was characterized by means of ultraviolet-visible light absorption spectrometry and atomic force microscopy. The friction and wear behavior of the polymer film sliding against brass, 440C stainless steel, Si3N4 and WC balls was evaluated on a microtribometer. It was found that the multilayer film was uniform and compact, and it registered a lowered friction coefficient and extended antiwear life while sliding against soft counterparts, in particular, a brass ball. This could be because the polymeric transfer film had an enhanced adhesion on the soft metallic counterpart in the presence of inter-transferred metallic debris. Contrary to the above, the PEM film had a higher friction coefficient and shorter antiwear life while sliding against Si3N4 and WC balls, possibly owing to a higher shearing stress in the presence of stiff and hardly deformable hard counterparts. In other words, the polymeric transfer film on the hard couterparts, if any, would be easily scaled off, leading to decreased antiwear life. Moreover, the differences in the friction and wear behavior of the PEM film sliding against different counterparts were closely related to the differences in the chemical and crystallographic structure of the counterparts (ceramics Si3N4 and WC, and metals brass and stainless steel). 相似文献
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In this article, wear and friction characteristics of a magnetorheological (MR) fluid were studied under different magnetic fields. Using a pin-on-disc tribometer, the wear loss and friction coefficient were obtained with and without a magnetic field. The friction and wear of three typical materials under magnetic field were investigated at various normal loads and rotating speeds. After the wear tests, the worn surfaces of specimens were observed using a scanning electron microscope (SEM) in order to investigate the wear mechanisms, and the contacting surfaces were analyzed by energy-dispersive X-ray spectroscopy (EDS) to investigate the variation of elemental composition on the worn surface. Test results showed that the MR fluid exhibits better tribological characteristics under a magnetic field compared to the case without a magnetic field. The general morphology of the MR particles and wear debris was observed to assist with the analysis of friction and wear. The SEM micrographs and EDS spectra of the worn surfaces showed that the predominant wear mechanism in the case of the steel and brass specimens was abrasive wear by asperities and MR particles on the worn surfaces, whereas a mixed wear mechanism that included adhesive wear and abrasive wear was observed in the case of the aluminum specimen. 相似文献
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Machine dynamics can contribute to a difference between results in coefficient of friction, vibration level and wear rate of the same tribo-couple concerning the compliance of the support provided to a sliding counterbody. The aim of the present work is revealing the effect of loading system inertia on laboratory tests results. A developed pendulum-type tribo-tester was used for testing ceramic–ceramic, ceramic–metal and metal–metal sliding contact combinations. Diamond-like, AlTiN, TiCN and AlCrN/Si3N4 PVD coatings and bare EN X30WCrV9-3 steel disks were tested against yttria-stabilized zirconia and EN 100Cr6 steel balls. Discussion on the mechanisms of materials degradation is based on SEM and EDS observations. It was found that inertia of loading system influences compaction of wear debris. 相似文献
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A.D. Sarkar 《Wear》1981,73(2):311-323
Surfaces of a 40–60 brass worn by three-body abrasion with SiC grits were observed under the scanning electron microscope. Similar observations were carried out on targets of steel and commercially pure aluminium which had been impacted with hardened steel balls. The brass develops alternating bands of hills and valleys when undergoing three-body abrasion. The hills wear by direct rubbing against the steel counterface. The valleys, however, are embedded with grits which are later removed and probably carry an amount of brass during their departure. The impact process creates craters which show severe deformation. Radial plastic flow of metal also occurs in the target around a crater. It appears that under repeated attack these deformed areas produce wear debris by microspalling. Metal may also be removed by nucleation and propagation of cracks. 相似文献
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Response surface methodology (RSM) based on a D-optimal design was employed to investigate the tribological characteristics of journal bearing materials such as brass, bronze, and copper lubricated by a biolubricant, chemically modified rapeseed oil (CMRO). The wear and friction performance were observed for the bearing materials tested with TiO2, WS2, and CuO nanoadditives dispersed in the CMRO. The tests were performed by selecting sliding speed and load as numerical factors and nano-based biolubricant/bearing materials as the categorical factor to evaluate the tribological characteristics such as the coefficient of friction (COF) and specific wear rate. The results showed that RSM based on a D-optimal design was instrumental in the selection of suitable journal bearing materials for a typical system, especially one lubricated by nano-based biolubricant. At a sliding speed of 2.0 m/s and load of 100 N, the bronze bearing material with CMRO containing CuO nanoparticles had the lowest COF and wear rate. In addition, scanning electron microscopy (SEM) examination of the worn bearing surfaces showed that the bronze bearing material lubricated with CMRO containing CuO nanoadditive is smoother than copper/brass bearing material. 相似文献
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为了实现油液金属磨粒的高精度测量,基于微流体制备了一种可检测电阻-电感参数的磨粒传感器。通过仿真获得了金属颗粒在时谐磁场中的磁化和涡流效应特征,并通过实验研究了电阻-电感检测的电压特性和频率特性。高频激励可以增强金属颗粒内部的涡流效应,而激励电压对传感器检测结果的影响不大。研究表明电感参数对铁磁性金属的检测能力强,电阻参数对非铁磁性金属的检测能力强。采用2.0 V、2.0 MHz的激励,通过比较分析电阻和电感检测结果,该传感器可有效识别直径60μm的铜颗粒和直径16μm的铁颗粒。这种基于线圈电阻参数检测非铁磁性金属磨粒的方法为增强磨粒传感器的综合测量性能提供了新思路。 相似文献
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Influence of surface roughness on the friction of TiC/a-C nanocomposite coatings while sliding against bearing steel balls
in humid air was examined by detailed analyses of the wear surfaces and the wear scar on the ball counterparts by atomic force
microscopy, optical, and confocal microscopy. It was observed that the surface roughness of the coatings essentially determines
the wear behavior of the ball counterpart, which consequently influences the transfer film formation. A rough coating causes
abrasive wear of the steel ball during the running-in period, which impedes the formation of a stable transfer film and leads
to higher values of coefficient of friction (CoF). Moreover, the CoF does not show a decreasing trend after the running-in
period, although the roughness of the coating was greatly reduced. Replacing the worn ball with a new one after the running-in
period yields lower CoF values similar to that observed for a smooth coating. In both of the cases, no wear of the steel ball
occurs and a stable transfer film forms and effectively covers the contact area. The influence of the wear debris on the formation
of the transfer film is also discussed. 相似文献
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