不同黏结方向对织物自润滑衬垫磨损性能的影响

织物自润滑衬垫是飞机关节轴承的关键自润滑材料,其摩擦磨损性能直接影响关节轴承的服役可靠性。对2种型号的关节轴承进行故障分析,结合摆动磨损试验研究衬垫裁剪和黏结方向对衬垫性能的影响。结果表明:45°方向裁剪的衬垫摩擦平稳性和耐磨性均优于0°方向裁剪的衬垫,为提高国产织物自润滑衬垫的服役性能提供了试验依据。     

织物衬垫自润滑关节轴承的研究现状与展望

针对飞行器等高端设备中广泛使用的免维护织物衬垫自润滑关节轴承,从其基体与自润滑织物衬垫材料、力学仿真与结构分析、性能试验、磨损与寿命分析诸方面介绍了国内、外的研究动态和发展趋势,并在总结现有研究工作的基础上,对织物衬垫自润滑关节轴承的未来发展趋势提出了一些看法.     

PTFE/芳纶织物衬垫自润滑关节轴承性能试验

对比分析研究了同型号国产与进口PTFE/芳纶织物衬垫自润滑关节轴承的粘结质量、摩擦学性能以及承载性能,研究结果表明:进口轴承的剥离强度、摩擦磨损性能以及承载性能均略优于国产同型号的关节轴承;国内自润滑关节轴承的衬垫粘结质量、摩擦学性能以及承载性能需要进一步提高。     

双工位往复式衬垫摩擦磨损试验机

介绍了自主研发的一种用于自润滑衬垫在不同试验条件下的双工位往复式摩擦磨损试验机,通过测量试验过程中产生的摩擦力、摩擦系数和磨损量的变化来研究衬垫的摩擦磨损性能。通过对2种不同织物型自润滑衬垫的摩擦磨损性能试验,证明该试验机性能稳定,测试系统准确可靠。     

纤维织物型摩擦材料弹性模量的实验研究

介绍了织物衬垫型摩擦材料压缩弹性模量的实验测试研究工作,在液压压机上应用差分位移测试装置精确测试了不同压力下的衬垫变形量,从而获得衬垫弹性模量。对不同工艺固化压力下的衬垫材料弹性模量进行了实验研究,测试了固化压力对自润滑衬垫材料力学性能的影响。准确的衬垫摩擦材料弹性模量数据对应用自润滑衬垫材料的轴承设计计算具有非常重要的意义。     

自润滑关节轴承轴向游隙和衬垫磨损量的关系研究

织物自润滑关节轴承游隙变化直接反映自润滑衬垫的磨损状态,确立轴承游隙和衬垫磨损量的对应关系,对掌握轴承磨损状态、判断轴承服役寿命具有重要意义。通过建立轴向游隙与衬垫磨损量关系的计算公式,结合典型轴承SA16的参数测定试验,评价了计算公式的合理性。结果表明:当轴向游隙为0.25 mm时,极端条件下的衬垫磨损量大于衬垫弹性状态下的数值。该研究可作为自润滑关节轴承的磨损失效判据的确定提供了理论参考。     

织物衬垫型关节轴承的力学分析

针对织物衬垫型关节轴承工作时的承载特性,利用ANSYS Workbench有限元数值模拟软件建立其接触应力和变形的分析模型,通过压缩试验,测试了织物衬垫的压缩弹性模量参数,对自润滑关节轴承进行了静态负荷试验,验证了力学分析模型的正确性,为织物衬垫型关节轴承的结构优化、强度校核提供了可靠、快捷的计算方法。     

等离子体表面改性对PTFE织物自润滑衬垫综合性能的影响

采用等离子体对PTFE织物进行表面改性,通过接触角测试、顶破强力、剥离强度和摩擦磨损寿命试验研究等离子体表面改性对PTFE织物亲水性、PTFE织物自润滑衬垫整体强度、剥离强度和摩擦磨损性能的影响。试验结果表明：等离子体表面改性后PTFE织物与水的接触角由135.9°降至91.8°,树脂对织物的浸润效果得到了改善;等离子体表面改性后PTFE织物衬垫的平均顶破强力为未处理衬垫的1.59倍;平均剥离强度为未处理衬垫的2.07倍;平均摩擦磨损寿命为未处理衬垫的1.66倍,衬垫的整体强度和耐磨性均得到了提高。     

裁切方向对PTFE织物自润滑衬垫剥离强度及摩擦磨损性能的影响

研究裁切方向对PTFE织物自润滑衬垫剥离强度及在不同工况下摩擦磨损性能的影响,分析造成性能差异的原因。结果表明:经向裁切衬垫的剥离强度最好,平均达1.49 N/mm;衬垫摩擦因数最低,平均为0.04;轴承圆周摆动的平均摩擦磨损寿命最长,达1 626 h;轴承在倾斜摆动情况下也保持了良好的摩擦磨损性能,说明经向裁切衬垫的综合性能优异;纬向裁切衬垫的综合性能最差,左斜向、右斜向裁切衬垫的综合性能居中。     

基体树脂和纳米颗粒含量对自润滑衬垫摩擦磨损性能的影响

用浸渍方法制备了含有不同比例基体树脂的Kevlar/聚四氟乙烯纤维(PTFE)织物型自润滑衬垫,用MM-200磨损试验机试验评价了制备衬垫的摩擦磨损性能,通过扫描电子显微镜(SEM)对磨损表面观测,探讨了衬垫中基体树脂含量和添加的纳米颗粒对衬垫摩擦磨损性能的影响机理。研究结果表明:衬垫存在一个较优的基体树脂含量范围,在此范围内,衬垫的摩擦磨损性能较为优异;纳米颗粒对衬垫的摩擦学性能和摩擦过程的阶段性变化产生影响,加入纳米颗粒后衬垫的抗磨性能得到明显改善。     

Sliding Wear of the Hybrid Kevlar/PTFE Fabric Reinforced Phenolic Composite Filled with Nano-titania

The Kevlar/polytetrafluroethylene(Kevlar/PTFE) fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the polymer-based composite.Unfortunately,up to now,published work on the effect of nano-particles on the tribological performance of the fabric composite which can be used as a self-lubricating liner is quite scarce.Therefore,for the purpose of exploring a way to significantly improve the tribological performance of the fabric composite,the tribological performance of the Kevlar/PTFE fabric composite filled with nano-titania is evaluated by using the block-on-ring wear tester.The scanning electron microscopy is utilized to observe the morphologies of worn surfaces of the fabric composites and the counterparts.The tensile properties of the composites are evaluated on the universal material testing machine.The test results show that the addition of nano-titania at a proper mass fraction of the matrix resin improves the wear resistance and the tensile strength,decreases the friction coefficient,and makes the wear volume of the composite reach a relative steady state more quickly;plastic deformation and microcutting are important for the wear of the fabric composite;a lubricating layer is formed on the worn surface of the composite during sliding,and the lubricating layer is critical for the tribological performance of the composite;the formation and properties of the lubricating layer are influenced by the nano-titania particles.The proposed study on the effect of nano-titania on the tribological performance of the Kevlar/PTFE fabric composite,especially on the evolution of the worn surface of the composite,provides the basis for further understanding of the influence mechanism of the nano-particles on the tribological performance of the composite and explores a method of improving the tribological performance of the composite.     

Influence of Ultrasonic Modified Liners on the Adhesive and Tribological Performances of Self-Lubricating Radial Spherical Plain Bearings

For self-lubricating spherical plain bearings, poor interface bonding strength between the polytetrafluoroethylene (PTFE)/aramid fabric hybrid woven liners and the outer rings can influence the full play of tribological performance of the self-lubricating liner. To solve this problem, the liners were modified by ultrasonic treatment. The adhesive performances of the modified and unmodified liners and the tribological performance of the self-lubricating radial spherical plain bearings with two kinds of liners were tested and compared. Results show that ultrasonic modification can improve the bonding performance of the liners significantly; compared to unmodified liners, the modified liners can decrease the friction coefficient, wear loss, and friction temperature of the bearings, which shows that ultrasonic modification can improve the tribological performance of self-lubricating spherical plain bearings. Bearings with modified liners only produced slight adhesive wear, but bearings with unmodified liners produced moderate adhesive wear and slight abrasive wear during test procedures.     

高频摆动自润滑关节轴承故障分析与改进验证

对高频摆动工况下自润滑关节轴承GE20-1的故障分析显示:织物自润滑衬垫和内圈球面镀硬铬涂层耐磨损性能不佳,出现偏磨现象;磨损严重处衬垫磨穿,内圈球面涂层仅剩1～2μm.为提升轴承耐磨损性能,采用了PTFE纤维面密度约20.1％的CD2#衬垫与内圈球面硬质合金涂层相组合的改进方案,改进轴承GE20-2经1500 h寿命...     

Influence of weave structures on the tribological properties of hybrid Kevlar/PTFE fabric composites

The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures (plain, twill 1/3 and satin 8/5) of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy (SEM). The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions: the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism of fabric composites.     

磷酸酯偶联剂改性衬垫对自润滑关节轴承性能的影响

利用 Instron5944型电子万能材料试验机和自制的关节轴承摩擦磨损试验机,研究磷酸酯偶联剂接枝改性处理衬垫对自润滑关节轴承黏接性能和摩擦磨损性能的影响。结果表明：磷酸酯偶联剂接枝改性处理衬垫可以有效提高轴承衬垫的黏接性能;自润滑关节轴承的摩擦磨损性能与摆动频率呈现明显的相关性,摩擦因数和磨损量均随摆动频率的增大而减小,而摩擦温度随之升高;衬垫经改性处理的轴承摩擦因数、磨损量以及摩擦温升均明显降低,表明衬垫经改性处理后改善了自润滑关节轴承的摩擦学性能。     

GF/PTFE自润滑纤维复合材料磨损性能热衰退研究

针对高频摆动关节轴承摩擦热对自润滑纤维复合材料摩擦磨损性能的影响,研制了高频使用条件下的玻璃纤维增强聚四氟乙烯(GF/PTFE)自润滑纤维复合材料,利用MYB～500高频高载摆动摩擦磨损试验机,对其进行不同摩擦温度下的摩擦磨损性能测试,研究摩擦热作用下材料自润滑性能和磨损性能衰退特征,分析磨损产物和摩擦表面以及不同摩擦温度下材料的磨损机理。结果表明,摩擦热对材料自润滑性能影响显著,适当的摩擦温度范围能够保证材料的自润滑性能,摩擦温度和摩擦因数之间互为耦合作用,对材料的磨损性能具有一定的影响;高摩擦热作用于自润滑过程及机理的改变,造成材料的磨损性能衰退现象。因此,不同温度下材料的磨损特征具有明显的差异化,其中低摩擦温度下(60～120℃)材料自润滑性能优异,磨损率很低;140℃摩擦温度条件下材料摩擦磨损性能开始衰退;材料在高摩擦温度下(140～180℃)的磨损初期自润滑性能良好、磨损轻微,而中后期磨损严重。微观分析表明,低摩擦温度下材料的磨损机理以轻微粘着和疲劳磨损为主;高摩擦温度下材料的磨损以片状剥落、纤维剪切破坏为主,且磨损面局部损伤特征明显,磨损严重。     

关节轴承磨损性能试验研究进展

总结了关节轴承的磨损性能试验以及摩擦磨损试验机的研究进展。影响关节轴承摩擦磨损性能的主要因素为载荷、摆频、摆动角度、温度、轴承材料和自润滑材料材质及含量,并根据已有的研究工作对将来试验机的发展趋势提出了一些看法。