三层复合轴承材料的试验研究

本文对研制的聚四氟乙烯和聚甲醛两种三层复合轴承材料进行摩擦磨损试验研究，并就轴承摩擦副表面结构对磨损性能的影响进行了试验分析，其结果可供实际应用时参考。     

臂架脂润滑滑动轴承摩擦性能试验研究

为研究工程机械臂架脂润滑滑动轴承在长期交变径向重载作用下的摩擦性能,研制了一种可以测量这类轴承摩擦力矩和摩擦系数的轴承试验台．该试验台不仅能够模拟轴承在低速重载工况下的工作过程,还能实现轴承与销轴之间的两种相对运动形式．对臂架滑动轴承工作过程中承受的主动力矩与和销轴摩擦力矩之间的关系进行试验研究,提出一种摩擦力矩和摩擦系数的试验求法,并应用于轴承磨损试验时摩擦系数的测量．试验结果表明:利用该方法可准确获得轴承与销轴之间的摩擦系数,并可利用其摩擦系数的发展趋势监测轴承当前的润滑与磨损状况,为轴承安全、可靠运行提供保障,并为设计者预估轴承寿命以及优化设计提供参考．     

大型球轴承摩擦力矩的计算

本文提出了大型球轴承摩擦力矩的试验研究方法和轴承摩擦力矩的经验公式。该成果有利于提高轴承的使用性能，也有助于轴承制造企业控制大型轴承的摩擦力矩，以提高轴承的制造精度。     

水润滑橡胶尾轴承鸣音试验研究

为了研究水润滑橡胶尾轴承鸣音产生的机理,在水润滑橡胶尾轴承鸣音台架模拟试验的基础上,结合橡胶尾轴承的摩擦特性,对试验结果进行了初步分析总结,揭示了各因素对水润滑橡胶尾轴承鸣音临界工况的影响规律。结果表明,水润滑橡胶尾轴承鸣音出现与否,主要取决于工作过程中轴承与轴颈的直接接触面积以及摩擦系数-速度曲线负斜率。     

SF-1材料水润滑艉轴承摩擦性能研究

针对传统船舶艉轴承的应用现状与不足,在SSB-100型船舶艉轴试验机上对SF-1高分子石墨轴承进行水润滑条件下的摩擦性能试验,分析了载荷、线速度和润滑水温变化对摩擦系数的影响规律以及摩擦磨损性能。结果表明,SF-1材料具有优良的自润滑性能,摩擦系数低,承载压力高以及耐磨性好,在船舶行业具有广阔的应用前景。     

水轮发电机镶嵌固体润滑剂轴承的应用研究

根据固体润滑机理设计了水轮发电机镶嵌轴承用固体润滑剂配方，对不同冷却条件下的产品进行摩擦磨损性能试验、台架模拟试验，用扫描电镜(SEM)对摩擦表面形貌进行分析。试验结果表明：以聚四氟乙烯为主体的固体润滑剂在金属表面可形成润滑转移膜；在水轮发电机特殊工况下(高载荷、往复运动)，固体润滑剂中的填料(纤维)在摩擦过程中出现局部取向现象，增加承载能力；当树脂与填料用量相近时，复合材料成型冷却条件对摩擦系数、磨损量的影响不明显；在铜套中镶嵌固体润滑剂可明显降低铜套与钢之间的摩擦系数与磨损量。     

填脂量对高速电主轴轴承性能的影响

使用滚动轴承高速试验台和BRG 3000轴承力矩测量仪研究了填脂量对轴承温升、摩擦力矩和振动性能的影响。试验结果表明,高速工况下填脂量对轴承温升、摩擦力矩和振动的影响均呈非线性变化,中低速工况下填脂量与温升呈正相关关系。高速工况条件下存在一个填脂量值使轴承的温升、摩擦力矩和振动的综合性能最好,确定最佳填脂量时需在一定的温度范围内兼顾振动性能,本文中在给定高速工况条件下轴承填脂量为自由空间的15%时轴承综合性能最佳,且少于FAG超精密轴承样本中推荐的26%的填脂量。     

高速电主轴热态特性的研究

主轴轴承高速下的急剧摩擦发热是影响和限制机床主轴转速和加工精度提高的主要原因．本文通过对高速电主轴热态特性的试验与研究，分析了高速下主轴轴承及主轴系统的热态特性及其影响因素，提出了改善主轴单元热态特性的措施．     

基于聚醚醚酮保持架的角接触球轴承特性仿真

针对高速重载工况下轴承保持架产生的问题导致轴承接触区摩擦温度升高,甚至诱发轴承失效的情况,将采用聚醚醚酮(PEEK)材料设计的带有突出侧梁结构的新型保持架装配的7014型号角接触球轴承与传统的胶木材料保持架轴承进行了对比分析。应用Fluent软件建立有限元模型进行数值分析,并通过轴承温升试验验证了数值模拟的正确性,研究了在不同工况下PEEK保持架的新结构对轴承腔内气流场的影响以及新材料对轴承温度场的影响,验证了PEEK轴承保持架的良好工作性能。     

金属底材对镶嵌轴承性能影响的试验研究

本文通过大量的试验研究和理论分析,探讨了不同金属底材对镶嵌轴承性能的影响。研究表明,不同的金属底材对轴承摩擦性能、使用寿命以及固体润滑材料的转移均有影响;恰当地选择润滑剂和金属底材可使轴承性能大大提高。     

退火温度对7022铝合金干摩擦性能的影响

对7022铝合金的不同温度退火试样进行干滑动摩擦磨损试验,用扫描电镜、显微硬度测试仪和三维形貌仪分析各试样的磨损机制.结果表明,退火温度对材料的显微硬度和摩擦磨损性能有明显影响,退火温度在200℃时,材料显微硬度和摩擦磨损性能最好,此温度下材料得到完全再结晶,且晶粒细化;摩擦磨损性能随着显微硬度的提高而减小.塑变磨损、磨粒磨损和疲劳磨损为7022铝合金的主要磨损机理.     

静电冷却技术对钛合金摩擦磨损性能的影响

为了更好地将静电冷却技术应用到钛合金的车削中,在自行设计的高速摩擦磨损试验装置上,进行了YG8/Ti6A14V摩擦副的摩擦磨损试验.结果表明:静电冷却技术可以有效地降低YG8/Ti6A14V摩擦副间的摩擦系数,在抑制摩擦副磨损的同时还可以改善Ti6A14V磨损表面质量.扫描电镜分析表明,硬质合金高速摩擦时的磨损机理以粘...     

紧固件表面锰系磷化膜的制备及摩擦磨损性能

为了提高核主泵紧固件的摩擦磨损性能,采用三种磷化工艺在40Ni Cr Mo7钢表面制备了锰系磷化膜.采用多功能材料表面性能测试仪进行了往复摩擦磨损试验,并研究了在有无润滑条件下,不同工艺对磷化膜摩擦磨损性能的影响.采用扫描电子显微镜和能谱仪表征了磨损前后磷化膜表面的组织形貌和化学成分,并分析了其磨损失效机制.结果表明,通过工艺Ⅱ制备的磷化膜具有最优的摩擦磨损性能.磷化膜特有的孔隙结构具有储油能力,有利于改善其摩擦学性能.随着法向载荷的增加,磷化膜的塑性变形增大,抗剪切强度降低,且摩擦系数呈先缓慢下降后急剧上升的趋势.     

Tribological Behavior of Nano-ZrO_2 Reinforced PTFE-PPS Composites

Polytetrafluoroethylene(PTFE) is a commonly used seal material for oil-free engine that is well known for its excellent tribological properties. In this work, the nano-ZrO_2 particles were used as the friction modifiers to improve the friction and wear performance of PTFE-PPS composites. The friction and wear characteristics of PTFE/PPS-nano-ZrO_2 composites were investigated by a block-on-ring tester under dry friction sliding condition. The worn surfaces, counterpart transfer films and wear debris were studied by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the increase of nanoZrO_2 content could effectively reduce the coefficient of friction and enhance the anti-wear ability of PTFEPPS composites. Especially, the best tribological properties of the composites were obtained when the particle content of nano-ZrO_2 was 10 vol%, the anti-wear performance of composite is 195 times better than that of the unfilled PTFE-PPS composite. Under different conditions, the coefficient of friction of PTFE/PPS-nano-ZrO_2 composites was more affected by the applied load while the wear rate was more affected by the sliding velocity.     

圆锥型螺旋槽气体动压轴承气膜压力分析

气体动压润滑轴承具有摩擦力小、速度高、磨损少等特性,对用可压缩气体润滑的圆锥型螺旋槽动压轴承进行了研究.由于圆锥轴承的特殊结构以及螺旋角的存在,对轴承的求解域进行了保角变换和斜坐标变换.采用局部积分有限差分在不连续求解域的纵向和横向推导出了控制方程在斜坐标系下的差分形式.并对轴承的压力分布进行了数值计算.结果表明:螺旋槽能很好实现气体轴承动压效应,压力在圆周方向上呈锯齿形分布,轴承的转速和槽深比不同对轴承的气膜压力的影响不同.     

Influence of water and oil immersion on the tribological properties of Excentrodendron hsienmu

Modern composite materials and lignum vitae are widely studied and used in water-lubricated bearings. Noise, wear and tear, environmental pollution, and limited resources restrict the application of these materials. Thus, alternatives to lignum vitae for water-lubricated bearings should be identified and developed. In this work, the chemical composition and mechanical and tribological properties of water-, vegetable oil-, and gear oil-immersed and wax- and water-extracted Excentrodendron hsienmu (E. hsienmu) samples were studied. Results showed that the friction coefficients of the water- and gear oil-immersed and waxand water-extracted E. hsienmu samples are significantly smaller than those of the wax- and water-extracted lignum vitae samples. The grinding crack widths of the water-extracted gear oil-immersed E. hsienmu samples are smaller than those of the water-immersed lignum vitae samples. The preliminary results show that it is possible to provide an environmentally friendly method that could replace lignum vitae and other composite materials for water-lubricated bearings.     

Tribological Properties of PVA-H Composites Reinforced by Nano-HA Particles

The friction and wear behaviors of tribological mechanical components were studied on a four-ball tester under dry conditions, and the wear mechanism was analyzed by observed worn surface using a scanning electron microscope （SEM）. It was found that the friction and wear properties were improved by the addition ofnano HA particles. The composite containing 1 wt% nano HA had the optimum friction coefficient. It is also found that the addition of nano HA increases the wear resistance of oure PVA-H and PVA-H composites.     

Friction and wear of textured surfaces produced by 3D printing

Surface texture patterns have great potential for improving tribological performance in terms of reducing friction and wear.The most common methods for surface texturing are laser and injection molding.The 3D printing method is also used to build parts,patterns,and molds that feature fine details for a wide range of applications because texture manufacturing by 3D printing is faster,more flexible,and less expensive than traditional techniques.To date,there has been no research on textured surfaces produced by 3D printing.Therefore,a new fabrication method using 3D printing to improve friction and wear properties is a topic worth exploring.In this study,a reciprocating friction tester was used to evaluate the friction and wear properties of different surface textures produced by 3D printing.The surface of specimens was examined by electron microscope and scanning electron microscope before and after the test.The results show that surface texturing can be applied to 3D printed parts to improve their friction and wear performance.