Design and optimization of fluid lubricated bearings operated with extreme working performances——a comprehensive review

Fluid lubricated bearings have been widely adopted as support components for high-end equipment in metrology,semiconductor devices,aviation,strategic defense,ultraprecision manufacturing,medical treatment,and power generation.In all these applications,the equipment must deliver extreme working performances such as ultraprecise movement,ultrahigh rotation speed,ultraheavy bearing loads,ultrahigh environmental temperatures,strong radiation resistance,and high vacuum operation,which have challenged the design and optimization of reliable fluid lubricated bearings.Breakthrough of any related bottlenecks will promote the development course of high-end equipment.To promote the advancement of high-end equipment,this paper reviews the design and optimization of fluid lubricated bearings operated at typical extreme working performances,targeting the realization of extreme working performances,current challenges and solutions,underlying deficiencies,and promising developmental directions.This paper can guide the selection of suitable fluid lubricated bearings and optimize their structures to meet their required working performances.

Molecular Mechanism and Molecular Design of Lubricating Oil Antioxidants

To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established here.The molecular mechanism of the antioxidant reaction of hindered phenol,diphenylamine,and alkyl sulfide are studied via molecular simulations.Calculation results show that the strong electron-donating ability and high hydrogen-donating activity of the antioxidant molecule and the low hydrogen-abstracting activity of free radicals formed after dehydrogenation are the internal molecular causes of the shielding of phenol and diphenylamine from scavenging peroxy free radicals,and the strong electron-donating ability is the internal molecular cause of the high activity of thioether in decomposing alkyl hydrogen peroxide.Based on this antioxidant molecular mechanism,a molecular design rule of antioxidant is proposed,namely“high EHOMO,large Q(S),low bond dissociation energy BDE(O—H)and BDE(N—H)”.Two new antioxidants,PAS-I and PAS-II,are designed and prepared by chemical bonding of hindered phenol,diphenylamine,and sulfur atoms.Experimental results show that these antioxidants both have excellent antioxidant effects in lubricating oil,and that PAS-II is the superior antioxidant,consistent with theoretical predictions.

Effect of Surface Roughness on Lubrication Performance of Bump-Type Gas Foil Bearings

Taking bump-type gas foil bearings as the research object,a deformation model of bump foil and a thin-plate finite element model of top foil were proposed.By solving Reynolds equation and energy equation,the pressure distribution and the temperature distribution of gas films in foil bearings were obtained.Further,a numerical method for calculating the lubrication performance of gas foil bearings with considering the surface roughness was proposed.With a specific example,effects of the surface roughness on the bearing lubrication performance were parametrically studied.The results indicate that rougher journal surface can lead to larger fluctuation of the lubrication performance,while surface roughness of top foil has few effects on the fluctuation.Moreover,the mean values of performance parameters almost remain constant at different values of surface roughness.

Assessment of Lubrication Property and Machining Performance of Nanofluid Composite Electrostatic Spraying(NCES)Using Different Types of Vegetable Oils as Base Fluids of External Fluid

The current study of minimum quantity lubrication(MQL)concentrates on its performance improvement.By contrast with nanofluid MQL and electrostatic atomization(EA),the proposed nanofluid composite electrostatic spraying(NCES)can enhance the performance of MQL more comprehensively.However,it is largely influenced by the base fluid of external fluid.In this paper,the lubrication property and machining performance of NCES with different types of vegetable oils(castor,palm,soybean,rapeseed,and LB2000 oil)as the base fluids of external fluid were compared and evaluated by friction and milling tests under different flow ratios of external and internal fluids.The spraying current and electrowetting angle were tested to analyze the influence of vegetable oil type as the base fluid of external fluid on NCES performances.The friction test results show that relative to NCES with other vegetable oils as the base fluids of external fluid,NCES with LB2000 as the base fluid of external fluid reduced the friction coefficient and wear loss by 9.4%-27.7%and 7.6%-26.5%,respectively.The milling test results display that the milling force and milling temperature for NCES with LB2000 as the base fluid of external fluid were 1.4%-13.2%and 3.6%-11.2%lower than those for NCES with other vegetable oils as the base fluids of external fluid,respectively.When LB2000/multi-walled carbon nanotube(MWCNT)water-based nanofluid was used as the external/internal fluid and the flow ratio of external and internal fluids was 2:1,NCES showed the best milling performance.This study provides theoretical and technical support for the selection of the base fluid of NCES external fluid.

Investigation on Relationship between Lubricating Performance and Stability of Emulsion for Cold Strip Rolling

比率的影响和为冷长带滚动的阴离子乳剂的稳定性上的 emulsifiers 的内容在学习也调查了的在场的这 paper.The 被调查 HLB ( hydrophile-lipophile 平衡)的效果不同稳定性和不同集中的效果上的没有离子的 emulsions.Based 的稳定性上的价值和 emulsifier 内容 adsorptivity 和磨擦系数上的乳剂，当时。

Research on the Relationship between Molecular Activity of Additives and Lubricating Performance of Aluminum Rolling Oil

In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.

Research on the Influencing Factors of Performance Management Innovation in Inspection Institutions on Enterprise Standardization Construction

As Chinese market economy develops rapidly,the market competing toward that of highlighting product quality level has become increasingly competitive,and enterprise standardization management also starts to play a more critical role in the competition.There is a statement of“extrasuperior enterprises sell standards”favored in the business circle,as standard is the magic weapon to improve the market competition of an enterprise and win the competition.In this paper,it firstly analyzes the current development conditions in domestic and foreign inspection institutions,and then studies the influencing factors of performance management innovation in inspection institutions on the enterprise standardization capacity.By analyzing factors influencing performance management innovation,it puts forward the hypothesis for the influence of performance management innovation in inspection institutions on the enterprise standardization construction,and draws a conclusion that the performance management innovation in inspection institutions can exert a positive influence on enterprise standardization capacity.

Cooperative effect of surface alloying and laser texturing on tribological performance of lubricated surfaces

The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with the diameter of 150μm and the depth of 30-35μm distributed circumferentially on the disc surface.The alloying element Cr was sputtered to the laser texturing steel surface by double glow plasma technique.A deep diffusion layer with a thickness of 30μm and a high hardness of HV900 was formed in this alloy.Tribological experiments of three types of samples(smooth,texturing and texturing+alloying) were conducted with a ring-on-disc tribometer to simulate the face seal.It is found that,in comparison with smooth steel surfaces,the laser texturing samples significantly reduce the friction coefficient.Moreover,the lower wear rate of the sample treated with the two surface techniques is observed.

Effect of filler on the self-lubrication performance of graphite antimony composites

Graphite antimony composites were prepared using a mechanical pressure infiltration method to force molten antimony into graphite preforms having a percolation micro-structure and a hop-pocket power filler. The micro-structural and macroscopic properties of the graphite antimony composites were analysed. Observations included metallographic analysis, physical properties and friction and wear behaviour. The results show that the wear loss is decreased by 12.24% and that the friction coefficient is re-duced by 32.61% after hop-pocket power was used. The research indicates that the hop-pocket power method gives a useful way to reduce friction coefficients and wear loss, and to increase service life and self-lubrication properties, of the graphite antimony seal-ing material as compared to carbon black.

粗糙度和轴向运动对艉轴承混合润滑性能的影响

针对大型船舶航行过程中出现船体变形时艉轴承的磨损状态异常这一问题,本文探究磨损表面粗糙度变化和轴向运动对于艉轴承混合润滑性能的影响,建立了耦合轴向运动和表面粗糙度的混合润滑模型,通过数值模拟得到轴承润滑特征的分布,分析轴向运动和粗糙度对轴承混合润滑特性的影响,并对该润滑模型进行验证。计算结果表明:在轴向运动和轴颈倾斜耦合作用下,油膜厚度沿轴向方向非线性减小,油膜压力和接触压力在局部出现峰值,轴瓦在局部出现较大变形;轴向速度增加会加强动压润滑效应,轴向运动对润滑特性的影响程度随着倾角的增大而增加;粗糙度越大承载能力越强,同时接触情况越严重,会加速轴承的局部磨损。

石墨烯纳米颗粒润滑性能分子动力学分析

文中为了研究基础油液蓖麻油中加入石墨烯纳米颗粒后蓖麻油的润滑性能改变情况,运用分子动力学知识和LAMMPS仿真软件进行了粒子数密度、粒子径向分布势函数及热导率分析,同时探究了混合石墨烯的蓖麻油对切削加工后材料表面的形貌影响。仿真和试验结果表明:石墨烯纳米颗粒具有亲油性,蓖麻油分子在石墨烯周围呈层状分布,形成润滑油膜,此油膜具有良好的导热性和抗压性,以及良好的润滑效果,石墨烯的加入改善了蓖麻油的润滑性能。

考虑表面粗糙度与空化效应的组合密封润滑分析

为了研究表面粗糙度及空化效应对压裂泵柱塞密封副密封性能的影响,基于稳态Reynolds方程,建立了粗糙峰和空化效应影响下组合密封的弹流润滑数值模型.在数值模拟基础上,采用有限体积法求解稳态Reynolds方程,研究了密封副在表面粗糙度影响下的油膜厚度、油膜压力、油膜流速分布规律,以及不同的往复速度和滑环表面粗糙度对密封性能的影响.结果表明,外行程流体动压效应微弱,油膜在空气侧附近会出现空化现象;较高的往复速度有利于减小泄漏量及摩擦阻力;滑环表面粗糙度从0.8μm增加到1.8μm时,净泄漏量与外行程摩擦力分别升高了180.4%和11.17%.因此,在工作过程中应设置较高的往复速度和使用较低粗糙度的滑环以提高密封性能.

不同测试方法在精密手术器械功能质量检查中的比较效果研究

目的:分析对比不同测试方法在精密手术器械功能质量检查中的测试效果,保障手术器械额安全使用。方法:通过查询相关文献及专业书籍,选定精密手术剪和持针器,选用不同的测试材料及方法。精密手术剪依次采用纱布、棉毛布及Interlock手术器械测试套装内的硅胶薄膜方法测试器械切割性能;精密持针器依次采用光照、夹针和Interlock手术器械测试套装内的夹线方法测试器械夹持性能。选取医院清洗消毒合格的100件精密手术剪和100件持针器进行测试效果研究,自制满意度问卷调查手术医生对器械使用的满意度。结果:100件精密手术剪经纱布、棉毛布和硅胶薄膜3种方法测试后,切割性能合格数量分别为94件、76件和58件,其差异有统计学意义(χ^(2)=36.526,P<0.05);手术医生对采用硅胶薄膜测试合格的精密手术剪使用满意率最高,为100%,棉毛布和纱布法分别为82.0%和67.0%,其差异有统计学意义(χ^(2)=48.439,P<0.05)。100件精密持针器经光照、夹针和夹线3种方法测试后,夹持性能合格数量分别为96件、78件和62件,其差异有统计学意义(χ^(2)=38.160,P<0.05);手术医生对采用夹线测试合格的精密持针器使用满意率最高,为100.0%、夹针和光照分别为79.0%和62.0%,医生使用满意率比较,差异有统计学意义(χ^(2)=57.705,P<0.05)。结论:采用Interlock手术器械测试套装内的测试物检查精密手术剪及持针器功能质量,能客观精准地反映器械功能状态,为器械定期维护与保养提供参考,确保器械安全使用。

基于红外光谱技术智能识别润滑油的研究进展

机器学习作为人工智能发展的核心,在各行业得到快速发展,近年来也成为润滑油领域研究的热点之一,标志着润滑油的研究不再局限于大规模的试验研究,高通量数据、机器学习、优化算法开始应用于润滑油的研究。文章介绍了基于红外光谱技术在润滑油种类鉴别、润滑剂筛选、润滑性能评估和润滑监测等方面的研究进展,并对未来基于红外光谱技术应用于智能识别润滑油的研究进行了展望。

基于氢谱修饰指数的润滑油添加剂抗磨损性能的预测研究

润滑油添加剂对保障机械运行的稳定性和安全性、延长设备的使用寿命、节约能耗具有重要作用,由于通过实验获得数据费时费力,故用定量结构摩擦性能关系研究方法,来获取抗磨损性能数据成为一种简便而高效的方法.为研究酰肼类及磷酸类润滑油添加剂抗磨损性能与结构的关系,定义并建构了新的氢谱修饰指数^(0)H,并计算36个酰肼类及磷酸类分子的电性距离矢量,筛选了M_(2)、M_(3)、M_(21)和M_(59),将这5个结构描述符作为BP神经网络的输入变量,磨损体积量度V s作为神经网络输出变量,用5-3-1的神经网络结构,构建了神经网络法预测模型,模型相关系数0.944,磨损体积量度V s的预测值与文献实验值的平均相对误差为2.61%,优于文献方法结果.结果表明:酰肼类及磷酸类润滑油添加剂抗磨损性能与氢谱修饰指数有良好的非线性关系,影响抗磨损性能的主要因素是分子中原子特性、基团片段的—CH_(3)、—CH_(2)—、>CH—、—O、—N—和—P—等.该研究对指导合成新型抗磨损性能好的化合物分子有理论意义.

CMQL和UEV下Incone1690镍基合金切削力和温度分析

低温微量润滑(CMQL)可以使切削阶段达到更优的切削摩擦性能,提升刀具耐磨性能并获得更优减磨效果;超声椭圆振动(UEV)能够提高难加工合金的切削性能。在超声椭圆振动基础上设置低温微量润滑条件,并通过实验分析其切削效果。研究结果表明:采用UEV和CCMQL模式时,切削力与进给力降低比例依次为62.3%与75.0%,在低温微量润滑过程能够实现更低温度控制效果,有效防止工件的热软化问题。普通切削时温度都接近445℃。UEV可以获得更低温度,同时运用UEV和CMQL处理方式,温度下降了16.1%,采用UEV和CCMQL方式时,温度下降19.5%。通过降低喷嘴角度的方式,获得更低切削雾滴温度,刀尖应力出现降低实现刀具保护,促进刀具寿命延长。该研究有助于改善合金切削工艺,对提高切削质量提供了一个思路。

鱼皮多肽作为水基润滑添加剂的摩擦学性能与机理研究

采用酶解和大孔树脂分离技术从渔业废弃物中提取了3种不同极性的多肽,研究了多肽在水乙二醇溶液中溶解性、摩擦学性能,并探讨了其摩擦学机理.结果表明,所制备的3种不同极性的多肽在水乙二醇体系中均具有良好的溶解性,且具有较高的热稳定性.摩擦学研究表明,多肽可显著提升水乙二醇溶液在钢/钢摩擦副间的减摩、抗磨性能,有效保护摩擦副表面,其中小极性的多肽抗磨性能最强,磨损体积比水乙二醇溶液降低55.49%,并且3种多肽均可显著提升水乙二醇的抗承载性能.多肽的分子结构中存在较多的极性基团,有助于多肽与金属摩擦副表面发生物理吸附,而且多肽在摩擦副表面还形成1层以含碳、氮有机化合物、铁氧化物为主的化学反应膜.因此,多肽优异的摩擦学性能是摩擦化学反应和物理吸附协同作用的结果.

Mo浓度渐变的AlCrMoSiN刀具涂层调控及切削性能

采用高功率脉冲磁控溅射和脉冲直流磁控溅射复合技术制备Mo浓度渐变的AlCrMoSiN梯度涂层,利用XRD、SEM和TEM、纳米压痕仪、划痕仪、高温摩擦试验机和立式加工中心对涂层微观结构和性能进行表征和测试。结果表明:沿涂层生长方向,随着Mo浓度渐变速率的增加,涂层硬度和弹性模量逐渐增大;临界载荷、摩擦因数和磨损率略有下降。当CrMo靶溅射功率从0.4 kW线性增至1.2 kW时,制备的AlCrMoSiN梯度涂层(涂层Ⅲ)硬度和弹性模量达到最大值,分别为23.8 GPa和317.7 GPa,临界载荷约57.3 N,此时摩擦因数和磨损率分别为0.51和2.20×10^(−8) mm^(3)/(N·mm),涂层耐磨性能最佳。经干铣削淬硬模具钢(P20H)试验,AlCrMoSiN梯度涂层铣刀的使用寿命比AlCrSiN涂层铣刀提高24.1%,连续切削40 min时,其切削温度比AlCrSiN涂层铣刀低65.1℃。

纳米微囊砂轮磨削工件表面自润滑层的形成

在磨削时磨削液难以有效渗入磨削区域起冷却润滑作用。提出利用润滑剂油酸(OA)填充碳纳米管(CNTs)制备CNTs@OA纳米微囊,并以其为填充剂制备树脂砂轮,磨削时随着纳米微囊的破裂,油酸可释放到磨削区形成自润滑层起润滑作用,从而提高砂轮的磨削性能。首先,制备纳米微囊并对其进行表征,分析微囊在砂轮中的存在形式,考察微囊的填充对其力学性能的影响;其次,研究砂轮磨削GCr15钢时纳米微囊的含量和磨削速度对磨削力、磨削温度、磨削比和表面粗糙度的影响,分析磨削过程中纳米微囊释放润滑剂油酸并产生自润滑作用的机制。结果表明,纳米微囊具有较好的热稳定性,能够抵抗树脂砂轮的固化温度并保护其中的油酸,当微囊的填充量小于16%时,砂轮的力学性能可以满足使用需求。与普通砂轮比,纳米微囊砂轮磨削时的磨削力可减小40%,磨削温度降低45%,工件表面粗糙度减少15%,磨削比可提高30%。磨削过程中,砂轮中的纳米微囊可将其空腔中的润滑剂油酸不断被释放到磨削界面上形成自润滑层,使砂轮具有了较好的自润滑作用,从而提高了其磨削性能。研究成果可为解决磨削过程的润滑问题提供一种可行的技术路线。

一种钻井液润滑剂的制备及其性能评价

基于现有钻井液润滑剂吸附、润滑抗磨性能差的问题,本文以多元醇、多元羧酸为原料制备一种强吸附、抗剪切的润滑剂(HR-1),采用极压润滑仪和四球摩擦试验机评价其润滑抗磨性能,并通过扫描电镜&能谱仪对其润滑机理进行探讨。实验发现,润滑剂HR-1显著提高了膨润土基浆的润滑抗磨性能,优于现场应用效果较好的润滑剂BLOE;另外,润滑剂HR-1使钢球表面的C元素含量升高以及Na、O元素含量降低,这表明,润滑剂HR-1的加入使润滑剂分子取代了原本吸附在钢球表面的钠基膨润土,且降低了摩擦腐蚀产物(Fe_(3)O_(4))的形成,起到润滑抗磨作用,达到保护金属的目的。