液压系统主动维护中目标清洁度的设置和优化

液压系统主动维护的首要问题为系统设定目标清洁度,最佳的目标清洁度应在系统的工作可靠性和维护成本之间取得平衡。介绍了目标清洁度设置的一般方法和步骤,并提出了进一步优化目标清洁度的理论和方法。目标清洁度的设置和优化是液压系统污染控制智能化研究的一个重要内容。     

改进装载机液压油箱焊接结构和焊接工艺提高油箱清洁度

本文阐述了液压油箱的结构和制造工艺.通过改进油箱结构,方便了焊接操作;通过细化焊接工艺,进一步明确了应焊焊缝及焊接规范.从而控制了焊接飞溅,减少了油箱内的清理量,提高了液压油箱的清洁度.     

机油清洁度检测与污染控制的研究

阐述了开展机油清洁度检测与机油污染控制工作的重要性，介绍了机油清洁度检测方法，提出了机油清洁度铁谱分析检测法，我国机械设备的机油清洁度检测规范，常用机械设备的机油清洁度控制等级以及防止机油污染的措施。     

滚动轴承洁净度及评定方法的商榷

通过对滚动轴承洁净度测试结果的分析和总结，指出JB/T7050—1993标准的一些不足，提出了密封轴承洁净度的另一种有效的测试方法——分离法，解决了轴承行业普遍面临的部分密封轴承油脂溶解难的问题，并提出了提高轴承洁净度水平的途径。     

Effects of Aryl Phosphate Ester Lubricant Additives on Crack Growth in Soda-Lime Glass

The growth of cone cracks in soda-lime glass during static loading with a spherical indenter shows that crack growth is accelerated at low energy release rates (low crack velocity) by tricresyl phosphate. Other aryl phosphate ester lubricant additive mixtures that contain predominantly larger molecules, as well as a synthetic hydrocarbon oil formulated with one of the mixtures, do not show enhancement of crack growth. Although reactivity in a test with static load can predict reactivity in a cyclically loaded test, lack of reactivity in a static test may not predict lack of reactivity in a cyclic test. Comparative tests with neat hydrocarbon oil and formulated oil under the same cyclically loaded conditions are needed to definitively determine whether the additives that are unreactive in these static tests influence crack growth in a bearing.     

含硫极压抗磨添加剂在菜籽油中的摩擦学性能研究

利用四球磨损试验机考察了以硫化异丁烯和硫化棉籽油作为菜籽油极压抗磨添加剂时的摩擦学性能,通过测定2种添加剂在不同含量下的最大无卡咬负荷(pB)和不同条件下的磨斑直径(WSD),分析和研究了载荷、摩擦时间、添加剂含量对菜籽油摩擦学性能的影响。试验结果表明:硫化异丁烯可以明显提高菜籽油的承载能力和抗磨性能,硫化棉籽油对提高菜籽油的承载能力和抗磨性能效果不明显,硫化异丁烯在菜籽油中的承载能力和抗磨性能明显优于硫化棉籽油。试验还表明添加剂的含量并非越高越好,否则WSD值将增大。     

Combined Effect of Nano-SiO2 and Nano-Al2O3 on Improving the Tribological Properties of Kevlar Fabric/Phenolic Laminate in Water

The combined effect of nano-SiO₂ and nano-Al₂O₃ as fillers on the tribological properties of Kevlar fabric/phenolic laminate (KFPL) in water was investigated. Results showed that the single addition of nano-SiO₂ at a proper content decreased the friction coefficient of KFPL to an ultralow value at the cost of an increased wear rate. The single addition of nano-Al₂O₃ at a proper content reduced the wear rate of KFPL with fluctuation in the friction coefficient curve. The combined addition of nano-SiO₂ and nano-Al₂O₃ not only endowed KFPL with an ultralow friction coefficient originated from nano-SiO₂ but also improved the wear resistance. This means that the combined addition of nano-SiO₂ and nano-Al₂O₃ can have positive effects and inhibit their negative aspects to some extent.     

Effects of lubricant additives on the performance of hydrodynamically lubricated journal bearings

A non-Newtonian rheological model to investigate theoretically the effects of lubricant additives on the steady state performance of hydrodynamically lubricated finite journal bearings is introduced. In this model, the non-Newtonian behavior resulting from blending the lubricant with polymer additives is simulated by Stokes couple stress fluid model. The formed boundary layer at the bearing surface is described through the use of a hypothetical porous medium layer that adheres to the bearing surface. The Brinkman-extended Darcy equations are utilized to model the flow in the porous region. A stress jump boundary condition is applied at the porous media/fluid film interface. A modified form of the Reynolds equation is derived and solved numerically using a finite difference scheme. The effects of bearing geometry, and non-Newtonian behavior of the lubricant on the steady-state performance characteristics such as pressure distribution, load carrying capacity, side leakage flow, and coefficient of friction are presented and discussed. The results showed that lubricant additives significantly increase the load carrying capacity and reduce both the coefficient of friction and the side leakage as compared to the Newtonian lubricants.     

磷酸酯与其它添加剂在菜籽油中摩擦相互作用研究

采用均匀试验设汁方法研究了磷酸三丁酯和磷酸三苯酯作为植物油基润滑油的抗磨剂与降凝剂T803-B、粘度指数改进剂ECA8358、清净剂T102、分散剂T152及L117之间的配伍性，探讨了相互作用摩擦机理。结果表明：T803B能增加其承载能力，T152能够促进其减摩性能，T102能降低磷酸三丁酯的抗磨作用。     

Lubricant Effects on White Etching Cracking Failures in Thrust Bearing Rig Tests

Abstract

White etching cracking (WEC) is a subsurface bearing failure mechanism influenced by a number of factors, including lubricant composition. Certain metal-containing lubricants have been reported to promote WEC-induced failure; however, the exact mechanisms linking lubricant effects on WEC propensity are still not fully understood. An interesting field that has not been elucidated is the influence of additive concentration and tribofilm growth on WEC initiation, propagation, and failure. The investigations conducted in this work involved two series of oil formulations: one with additives that give rise to WEC (WEC oils) in different combinations and concentrations and another with additives that do not cause WEC (non-WEC oils). A mini traction machine (MTM) in combination with a spacer layer imaging machine (SLIM) was employed to study the growth of tribofilms and their influence on friction response. Insights from the MTM-SLIM study allowed for better interpretation of FE8 bearing tests. When using oils that contribute to WEC formation, the tribofilm-induced WEC mechanism was confirmed, with cracks initiating as early as after 20 h of FE8 testing. Metal-containing additives were found to favor the formation of WECs by generating a high-friction tribofilm and increasing the water content in the lubricant. Furthermore, the source of subsurface H associated with WEC failure is investigated using heavy water (D2O)-saturated oil. A mechanism of water dissociation induced in tribofilm growth (incubation period) is proposed in this article.     

Combined Effect of Chemical Surface Treatment of Kevlar Fabric and PTFE Fillers on the Water-Involved Tribological Performance of Kevlar Fabric/Phenolic Laminate

The combined effect of chemical surface treatment of Kevlar fabric and solid lubricant polytetrafluoroethylene (PTFE) fillers on the water-involved tribological performance of Kevlar fabric/phenolic resin laminate was investigated. Results showed that the interfacial adhesion between Kevlar fabric and resin was improved because of chemical surface treatment on the Kevlar fabric, leading to a decreased wear rate but an increased friction coefficient of the laminate. The addition of PTFE fillers not only enhanced the wear resistance of the laminate but reduced its friction coefficient. Furthermore, the combination of surface treatment on Kevlar fabric and the PTFE filling can improve the wear resistance and friction-reducing property of the laminate to the largest extent.     

AV40-12轴流鼓风机伺服液压系统污染控制的研究与应用

对AV40-12轴流鼓风机伺服液压系统故障的主要原因进行分析后,从设计、安装、维护管理等上面提出了解决办法,通过从源头上人手,增加过滤油箱用以提高系统的清洁度,从而将油液污染度控制在许可值之内.     

Effect of Graphite on Friction and Wear Characteristics of Molybdenum Dithiocarbamate

The effects of graphite powder on the friction and wear characteristics of molybdenum dithiocarbamate MoDTC were studied in reciprocated sliding contact using a ball-on-plate type tester. The oil used was squalane, a pure hydrocarbon. The addition of MoDTC alone to the oil showed a high coefficient of friction at an early stage of a rubbing test, since the extent of the formation of a surface film containing MoS₂ was insufficient to decrease the coefficient of friction. The high friction at the early stage brought about noticeable wear. On the other hand, the addition of graphite powder together with succinimide-type dispersant to the oil containing MoDTC considerably improved the friction and wear performance not only at the early stage but also at the steady stage. The added graphite powder seems to cover the part of rubbing surfaces without a film containing MoS₂ to reduce the friction and wear, not only at the steady stage after the running-in process, but also in the running-in process or at the early stage.     

Effects of blended vegetable‐based cutting fluids with extreme pressure on tool wear and force components in turning of Al 7075‐T6

In this study, performances of four different types of vegetable‐based cutting fluids (VBCFs) over a commercial mineral cutting fluid were evaluated for machinability of Al 7075‐T6. Lubrication properties of VBCFs were improved with additive of extreme pressure. Cutting force and tool wear data were obtained for performance analyses of cutting fluids during longitudinal turning of Al 7075‐T6. Cutting, feed and radial forces indicated 1.70–38.25% improvements for VBCFs over the commercial mineral cutting fluid. The lowest average values of flank and nose wears obtained with blended cutting fluid containing 12% of extreme pressure were 0.09 and 0.10 mm, respectively, whereas these values for the commercial mineral cutting fluid were 0.18 and 0.15 mm. The scanning electron microscope results showed adherence of workpiece material occurred on rake and flank faces, and flank and nose wears were the dominant wear modes. It was found that performances of VBCFs during turning of Al 7075‐T6 were better than that of the commercial mineral cutting fluid. Copyright © 2012 John Wiley & Sons, Ltd.     

汽车自动变速箱过滤系统设计方法与试验研究

液压控制系统是电液控制自动变速箱的核心,而油液过滤系统正常工作是自动变速箱电液系统能够正常工作的基本保证。以某款自动变速箱为例,对比了不同油液环境下的自动变速箱电磁阀控制曲线,说明了油液污染带来的危害;分析了自动变速箱不同类型的过滤系统,阐明了过滤系统的设计过程及应重点注意事项,同时结合过滤试验方法和试验结果,说明了自动变速箱过滤系统的开发和试验过程。同时,针对自动变速箱的零件清洁度控制提出有效的辅助控制手段。     

Additives for Rape Seed Oil 1: Preparation and Tribological Behaviour of a Sulphurised Rape Seed Oil Lubricant Additive

A new type of environmentally friendly lubricant additive ‐ a sulphurised rape seed oil additive ‐ was prepared, and the chemical structure characterised using infrared spectroscopy. The tribological properties of the additive in a rape seed base oil were evaluated using a friction tester. The morphologies and tribochemical species of worn surfaces were analysed by means of X‐ray photoelectron spectroscopy. The results show that the additive increased the load‐carrying capacity and improved the antiwear and friction‐reducing properties of the rape seed oil. The inferred lubrication mechanism is that a high‐strength adsorption film and a tribochemical reaction film form on rubbing surfaces due to the carrier effect of the long‐chain rape seed oil molecules, the high reactivity of sulphur, and their synergism.     

废润滑油再生中的过滤分离工艺技术研究

介绍了国内外废润滑油再生的现状，对再生过程选择适宜的白土进行精制及精制后的润滑油与白土的过滤分离条件进行了研究。     

硫、磷系添加剂对菜子油生物降解性能影响的研究

以精制菜子油为基础油，考察了几种硫化脂肪添加剂和磷系添加剂对其生物降解性能的影响。试验结果表明，菜子油中加入添加剂后会对其生物降解性能产生影响。添加剂的种类不同，对菜子油的生物降解性能的影响也不相同。所添加的几种添加剂都不同程度地降低了菜子油的生物降解性能，但降幅不大，其生物降解率仍在95％以上。硫、磷系极压抗磨添加剂配伍对菜子油生物降解性能有一定的影响。其中RC2317与P120配伍对菜子油的生物降解性影响不大，而RC2526和RC2540与P120配伍，则使菜子油的生物降解率下降很大。     

硫化异丁烯与ZDDP复配对菜籽油摩擦学性能的影响

以菜籽油为基础油,选择硫化异丁烯(T321)为极压添加剂、ZDDP为抗氧抗腐剂,采用均匀试验方法设计试验方案,并测定在不同添加剂含量下的pB值(最大无卡咬负荷)和WSD值(磨斑直径),利用逐步回归法和扫描电子显微镜(SEM)分析了基础油和添加剂之间的配伍性及其对菜籽油摩擦学性能的影响。结果表明:当硫化异丁烯的含量低时会降低菜籽油的承载能力,当含量高时可提高菜籽油的承载能力,ZDDP无论在低含量还是高含量均可提高菜籽油的承载能力。ZDDP对菜籽油抗磨性能的作用大于硫化异丁烯。