无油润滑涡旋压缩机的摩擦学问题研究

发布时间：2018-06-13 13:49

本文选题：无油涡旋压缩机 + 表面粗糙度　；参考：《兰州理工大学》2012年硕士论文

【摘要】：涡旋压缩机以结构简单、噪声低、效率高和可靠性好等优点，在压缩机领域得到快速发展。近年来，随着工业生产的飞速发展，一些特殊场合如食品、制药、空气分离等领域常需要不被润滑油污染的高压气体，为了满足生产的需求，无油润滑形式的涡旋压缩机产品成为了这些特殊场合的首选。目前无油润滑涡旋压缩机摩擦副的润滑是通过镶嵌自润滑材料来实现的。因此，自润滑材料的性能，以及与钢对偶摩擦时的特性，对压缩机的性能有着重要的影响，所以开展自润滑材料性能及与钢对偶摩擦的研究，对无油涡旋压缩机的自润滑材料的设计和压缩机的理论计算具有重要的实际指导意义和理论价值。本文首先在触针式表面轮廓仪上分别采集了聚醚醚酮（PEEK）压膜成形原始表面和经砂纸打磨表面的轮廓曲线，采用结构函数法对所采集的表面轮廓曲线进行了分形表征，，结果表明聚醚醚酮压膜成形初始表面和打磨之后的表面均具有显著的分形特征。为探究PEEK不同表面粗糙度与分形维数之间的关系，根据PEEK不同表面粗糙度的轮廓曲线的分形特征和分形维数，利用SPSS统计软件对粗糙度和分形维数两组数据进行拟合并得到最佳的拟合模型。结果表明：分维可以作为一个独立的表征参量来表征粗糙表面的复杂程度和粗糙度水平；由拟合结果可知，对于PEEK，分维与粗糙度存在单调递减的关系，粗糙度数值越大，表面越粗糙，分维数值越小；通过分维值与粗糙度之间的关系式，在一定范围内，可以通过粗糙度值计算得出分维值D。基于分形理论对PEEK表面分形维数、摩擦系数分形维数及其关联对PEEK自润滑材料原始表面特征与球墨铸铁对偶摩擦副摩擦性能的关系进行了研究。通过触针式表面轮廓仪获得PEEK改性前后不同表面的粗糙度并采集了其轮廓曲线和数据，在UMT-3摩擦试验机上对改性前后不同表面粗糙度的PEEK与球墨铸铁配对进行了变载荷、定速度的摩擦试验。运用分形理论随机过程的结构函数方法，分别分析了表面轮廓曲线和摩擦系数曲线的分形特征，并计算出不同表面轮廓曲线以及摩擦系数曲线的分形维数。结果表明：PEEK的表面轮廓曲线和实验摩擦系数曲线具有明显的分形特征；摩擦信号的分形维数与材料的性能、加工方法、材料的初始表面形貌以及摩擦实验工况有较大的关系。摩擦系数曲线分形维数随初始表面分形维数的增大而减小。将球墨铸铁分别与PEEK和PI的复合材料对偶进行了摩擦实验，实验结果表明：原始表面PEEK复合材料的摩擦系数及其相应的分形维数值较小，可以作为很好的自润滑材料；对自润滑材料表面的加工可以使用压膜成形或机加工的方法。
[Abstract]:Scroll compressor has been developing rapidly in the field of compressor because of its simple structure, low noise, high efficiency and good reliability. In recent years, with the rapid development of industrial production, some special occasions, such as food, pharmaceutical, air separation and other fields often need not to be contaminated by lubricating oil high pressure gas, in order to meet the needs of production, Non-oil lubricated scroll compressor products have become the first choice for these special occasions. At present, the lubrication of friction pair of oil-free scroll compressor is realized by self-lubricating material. Therefore, the properties of self-lubricating materials and the characteristics of friction with steel have an important effect on the performance of compressors. It is of great practical significance and theoretical value for the design of self-lubricating materials for oil-free scroll compressors and the theoretical calculation of compressors. In this paper, the contour curves of the original surface formed by polyether ether ketone (PEEK) pressure film and the surface polished by sandpaper were collected on the stylus surface profilometer, and the surface contour curves were characterized by the structure function method. The results show that both the initial surface and the polished surface of PEK film have significant fractal characteristics. In order to explore the relationship between different surface roughness and fractal dimension of peek, according to the fractal characteristic and fractal dimension of contour curve of peek surface roughness, The best fitting model is obtained by combining roughness and fractal dimension with SPSS statistical software. The results show that the fractal dimension can be used as an independent representation parameter to characterize the complexity and roughness level of rough surface, and the fitting results show that for PEEK, the relationship between fractal dimension and roughness decreases monotonously, and the roughness value increases. The rougher the surface, the smaller the fractal dimension, and the fractal dimension D can be obtained by calculating the roughness value in a certain range by the relation between fractal dimension and roughness. Based on fractal theory, the relationship between the surface fractal dimension of peek, the fractal dimension of friction coefficient and the correlation between the original surface characteristics of peek self-lubricating materials and the friction properties of dual friction pairs of nodular cast iron was studied. The roughness of different surfaces before and after peek modification was obtained by using a stylus surface profilometer, and the profile curves and data were collected. The pairing load of peek with different surface roughness before and after modification was studied by UMT-3 friction tester. A constant velocity friction test. The fractal characteristics of the surface contour curve and the friction coefficient curve are analyzed by using the structure function method of the random process of fractal theory, and the fractal dimensions of the different surface contour curves and the friction coefficient curves are calculated. The results show that the surface profile curve and the experimental friction coefficient curve have obvious fractal characteristics, and the fractal dimension of friction signal is related to the properties of the material, the processing method, the initial surface morphology of the material and the friction experimental conditions. The fractal dimension of friction coefficient curve decreases with the increase of initial surface fractal dimension. Friction experiments were carried out between ductile iron and peek and Pi composites respectively. The experimental results show that the friction coefficient and the corresponding fractal dimension of the original PEEK composite are smaller and can be used as a good self-lubricating material. The surface of self-lubricating material can be machined by film forming or machining.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH45

【引证文献】