【作者】 明尔扬；

【导师】 张朝辉；

【作者基本信息】 北京交通大学 ， 机械设计及理论， 2012， 硕士

【摘要】 PTFE/PEEK(聚四氟乙烯／聚醚醚酮)聚合物涂层具有独特的性质,如自润滑、低磨损、抗腐蚀、耐辐射和良好的化学稳定性等,有广泛的应用前景。随着人们要求更洁净的压缩气体,全无油润滑压缩机应运而生。现有的全无油润滑压缩机中,活塞销采用脂润滑。该润滑方式有其局限性,例如易失效、溢出及在真空环境易蒸发等,故不能完全满足全无油或稳定润滑的条件。因此,本文提出采用PTFE/PEEK涂层改进活塞销的润滑方式,提高全无油润滑压缩机工作性能及延伸其适用场合。首先,设计一台全无油润滑压缩机的活塞组部分,以获得在SRV上进行PTFE/PEEK涂层试验的参数。然后,采用粉末静电喷涂法制备PTFE/PEEK涂层,并运用正交试验设计法考察预热温度、涂层厚度和工作温度对PTFE/PEEK涂层性能的影响。结果表明：250℃预热基底,喷涂厚度100μm-150μm,在150℃温度下工作时,PTFE/PEEK涂层有着良好的摩擦学性能。随后考察了往复摩擦冲程的影响,发现在涂层厚度小于150μm的范围内,随着涂层厚度的增加,冲程对PTFE/PEEK涂层的摩擦系数影响越小,并且较大的冲程可获得更小的摩擦系数。最后,运用ANSYS对PTFE/PEEK涂层进行模拟工作环境热分析。分别对比压缩机两级在活塞销固定和活塞销旋转两种定位方式下的活塞销温度分布,得出：低级的活塞列可以满足较优工作温度,而高级的则不能,且活塞销可旋转时,活塞销上温度的分布更均匀,利于减小集中热应力。本文的研究证明了使用PTFE/PEEK涂层的可行性,并且初步寻找到可应用于全无油活塞式压缩机活塞销涂层润滑的设计参数,为全无油润滑压缩机的设计提供新思路,新方法和延伸其使用场合,同时也为PTFE/PEEK涂层的应用提供参考。更多还原

【Abstract】 PTFE/PEEK (Polytetrafluoroethylene/Polyetheretherketone) polymer coating has extensive prospect of application due to its unique hybrid properties, such as self-lubrication, high wear resistance, corrosion resistance, radiation resistance and great chemical stability. As higher demands of clean compressed air, the oil free compressor had come out. The wrist pins in this compressor are lubricated by grease which is limited in some cases, such as the failure and leakage of grease or evaporation in vacuum, so that they cannot meet good or stable lubrication totally. Therefore, in this thesis, PTFE/PEEK coating was invited to improve it by taking the place of grease for better performance of oil free compressor and expanding its scope of application.Firstly, an oil free air compressor was designed to obtain the parameters for PTFE/PEEK coating tests on SRV tribometer.Secondly, PTFE/PEEK coatings were prepared by electrostatic powder spraying method and factors were investigated on the preheating temperature, coating thickness and working temperature by the orthogonal experimental method. The results show that250℃preheating temperature,100μm-150μm coating thickness and150℃working temperature are better conditions for playing good performance of PTFE/PEEK coating. For the influence of stroke, in the range of coating thicknesses from20μm to150μm, the COF values are not influenced too much by strokes as the increasing of coating thickness, and bigger strokes can obtain lower COF values.Finally, ANSYS was used to build a transient thermal model to analyze the temperature distribution in two working conditions-the fixed wrist pin and the rotated wrist pin. The results show that the first stage can meet the better conditions which are obtained by tribological tests, and the second stage cannot. Also, the temperature distribution becomes uniformity as wrist pin rotated, which can limit the thermal stress.The conclusions in this thesis prove the feasibility of application of PTFE/PEEK coating, and provide a new design method of oil free compressor using polymer coating lubrication, and provide a reference of PTFE/PEEK coating application.更多还原