气体挤压膜悬浮平台的理论与实验研究

发布时间：2018-03-17 09:39

本文选题：气体润滑　切入点：挤压膜　出处：《南京航空航天大学》2012年硕士论文　论文类型：学位论文

【摘要】：气体挤压膜润滑是一种新型的润滑方式，它通过压电陶瓷或者其他方式使得两表面发生法线方向的高频振动，使其中的气体受到不断的挤压从而产生较大的气膜压力。相对于其他润滑方式，具有结构简单、有自适应能力等优点，但由于气体挤压膜的承载能力相对较小，因而多应用于轻载、精密仪器以及微电子系统行业等。气体挤压膜润滑有着广阔的应用前景，对气体挤压膜的研究具有重要的意义。随着微细加工和微型机械技术的发展，气体润滑中的气膜厚度越来越小，甚至达到纳米级别，在这种情况下，必须考虑表面粗糙度以及气体稀薄效应对于气体挤压膜的影响。本课题首先建立了气体挤压膜润滑的基本理论模型，并通过数值方法对气体挤压膜雷诺方程进行了求解，得到了气体挤压膜的承载能力，并分析了激振振幅、气膜厚度、激振频率等因素对于气体挤压膜承载能力的影响。随后针对粗糙表面，根据平均膜厚模型和平均流量模型对气体挤压膜雷诺方程进行了修正，讨论了不同的表面粗糙度对于气体挤压膜承载能力的影响。对于极薄的气膜，通过壁面速度滑移条件，分析得到了气体稀薄效应影响下气膜压力的变化情况。最后研究了表面粗糙度和气体稀薄效应的综合影响。实验部分，在理论分析的基础上，对气体挤压膜的性能进行了实验测试，，包括实验台和气膜承载力测量装置的设计、实验装置的选择和调试以及实验数据的获取与处理等。理论和实验的结果表明，超声振动可以形成具有一定承载能力的气体挤压膜，其承载能力由多因素决定，其中比较重要的是激振的振幅和气膜的厚度。此外通过选取合适的加工方法，在气体挤压膜上下表面得到一定的纹理，可以一定程度的增大气膜承载力。而当气体挤压膜膜厚达到亚微米甚至纳米量级时，气体稀薄效应对于气体挤压膜的影响非常明显。
[Abstract]:Gas extrusion film lubrication is a new type of lubrication, which causes high frequency vibration in the normal direction of the two surfaces through piezoelectric ceramics or other means. Compared with other lubrication methods, it has the advantages of simple structure and adaptive ability, but the bearing capacity of the gas extrusion film is relatively small. Therefore, it is widely used in light load, precision instruments and microelectronic system industries. The lubrication of gas extrusion film has a broad application prospect, which is of great significance to the study of gas extrusion film. With the development of micro machining and micro mechanical technology, The thickness of gas film in gas lubrication is becoming smaller and smaller, even to the nanometer level. In this case, the effect of surface roughness and gas rarefaction on the gas extrusion film must be considered. In this paper, the basic theoretical model of gas extrusion film lubrication is established, and the Reynolds equation of gas extrusion film is solved by numerical method. The bearing capacity of gas extrusion film is obtained, and the amplitude of exciting vibration and the thickness of gas film are analyzed. The effect of exciting frequency on the bearing capacity of gas extrusion film is studied. Then the Reynolds equation of gas extrusion film is modified according to the average film thickness model and the average flow rate model for the rough surface. The influence of different surface roughness on the bearing capacity of gas extrusion film is discussed. The variation of film pressure under the influence of gas rarefaction effect is obtained. Finally, the comprehensive effect of surface roughness and gas rarefaction effect is studied. In the experimental part, based on the theoretical analysis, the performance of the gas extrusion film is tested, including the design of the test bench and the measuring device for the bearing capacity of the film, the selection and debugging of the experimental device, the acquisition and processing of the experimental data, etc. The theoretical and experimental results show that ultrasonic vibration can form a gas extrusion film with certain bearing capacity, and its bearing capacity is determined by many factors. The amplitude of the excitation and the thickness of the film are more important. In addition, a certain texture is obtained on the upper and lower surface of the gas extrusion film by selecting the appropriate processing method. When the thickness of gas extrusion film reaches sub-micron or even nanometers, the effect of gas rarefaction on gas extrusion film is very obvious.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH117.2

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