多孔质气浮轴承的理论实验研究

发布时间：2018-03-16 11:40

本文选题：多孔质气浮轴承　切入点：分形理论　出处：《天津大学》2012年硕士论文　论文类型：学位论文

【摘要】：气浮轴承广泛运用于航天、精密制造领域的超精密机械及测量装备上，利用多孔材料制成的气浮轴承与其他类型的气体静压轴承相比能够提供更高的承载力和刚度，因而多孔质气浮轴承受到了广泛的关注。本文对多孔材料的渗透率计算进行了理论分析，同时对渗透率不同的多孔材料制成的多孔质气浮轴承进行了大量的实验并对多孔气浮轴承的特性进行研究，主要完成的工作和结果如下：（1）多孔材料的渗透率是多孔质气浮轴承的关键参数，因此对渗透率的计算尤为重要，针对本课题所使用的多孔材料，，研究利用分形理论计算多孔材料渗透率的可行性，表面三维形貌为研究多孔材料的结构参数提供了基础，本文理论计算了该材料的分形维数和孔隙通道的迂曲维数以及材料的渗透率，利用多孔材料渗透率的实际测量值对理论分析结果进行验证。（2）为研究多孔材料的微结构，本文提出了一种针对性的算法，由于本文的多孔材料是由大量直径成正态分布的铜颗粒倒入圆柱形的容器内再经过施加巨大的载荷压缩而成，因此可利用计算机软件Matlab对铜颗粒的堆叠状态进行三维模拟，在该过程中考虑了铜颗粒堆叠的边界条件及平衡条件，对模拟结果分析进一步得到了多孔材料的结构信息。（3）搭建多孔材料渗透率的测量平台，测量了多孔材料的渗透率，同时对比多孔材料表面未加工与加工时的渗透率，研究了不同的加工工艺对多孔材料渗透率的影响。（4）对多孔气浮轴承加载实验装置进行改进，对多孔质气浮轴承进行加载实验，测量其在不同加载力下的工作性能，并且针对同一多孔气浮轴承，对其表面进行研磨，对比研磨前后的轴承承载力的变化，同时研究多孔材料渗透率的不均匀性对多孔气浮轴承的整体工作性能的影响，测量每个局部块的不同方向上的渗透率同时完成了对多孔材料整体渗透率的拟合，根据实验结果对平均孔隙大小不同的多孔质气浮轴承的振动现象进行研究。上述研究不仅能够为多孔质气浮轴承的研究制造提供理论和实验依据，而且也为类似的多孔材料的分形维数及渗透率的计算提供基础。
[Abstract]:Air bearing is widely used in aerospace, precision manufacturing field of ultra-precision machinery and measuring equipment. Air bearing made of porous materials can provide higher bearing capacity and stiffness than other types of aerostatic bearings. Therefore, porous air bearing has attracted wide attention. In this paper, the permeability calculation of porous materials is theoretically analyzed. At the same time, a large number of experiments were carried out on porous air bearing made of porous materials with different permeability, and the characteristics of porous air bearing were studied. The main work and results are as follows:. The permeability of porous material is the key parameter of porous air bearing, so it is very important to calculate the permeability. In view of the porous material used in this paper, the feasibility of using fractal theory to calculate the permeability of porous material is studied. The 3D surface topography provides the basis for studying the structural parameters of porous materials. In this paper, the fractal dimension, the tortuous dimension of pore channels and the permeability of porous materials are calculated theoretically. The theoretical analysis results are verified by the measured values of permeability of porous materials. In order to study the microstructure of porous materials, a new algorithm is proposed in this paper. Because the porous materials in this paper are composed of a large number of copper particles of normal distribution, which are poured into a cylindrical container and then compressed by a huge load. Therefore, the computer software Matlab can be used to simulate the stacking state of copper particles. The boundary conditions and equilibrium conditions of the stacking of copper particles are considered in the process, and the structural information of porous materials is obtained by analyzing the simulation results. The permeability of porous materials was measured by using a platform to measure the permeability of porous materials. The influence of different processing processes on permeability of porous materials was studied by comparing the permeability of porous materials with that of non-machined and processed porous materials. 4) improving the loading experimental device of porous air bearing, carrying out loading experiment on porous air bearing, measuring its working performance under different loading forces, and grinding its surface for the same porous air bearing. Comparing the bearing bearing capacity before and after grinding, and studying the influence of permeability inhomogeneity of porous material on the overall working performance of porous air bearing. The permeability of each local block was measured in different directions and the whole permeability of porous material was fitted. According to the experimental results, the vibration phenomenon of porous air bearing with different average pore size was studied. These studies can not only provide theoretical and experimental basis for the study and manufacture of porous air bearing, but also provide a basis for the calculation of fractal dimension and permeability of similar porous materials.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.35;TB383.4

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