【作者】 王鹏；

【导师】 杜建军；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2018， 硕士

【摘要】 弹性箔片气体动压轴承技术,作为气体润滑技术中重要的组成部分,是敏感性工业技术,在航空航天和国防军工等高科技领域具有非常广阔的应用前景。弹性箔片气体轴承作为核心部件之一,广泛应用于无油涡轮增压器、低温冷却机械和微型燃气轮机等。箔片气体轴承由于其无润滑油、维护成本低、环境适应性强等特点,在高速透平机械中具有良好的发展潜力和应用前景。有关悬臂式多叶箔片径向轴承的研究文献较少,且对多叶型箔片轴承的研究大多假设箔片之间为线接触,提出的面接触假设也存在很多问题:如没有考虑箔片与轴套间的面接触、建模过程中忽略切向摩擦力、箔片装配时忽略初始预紧力等,本文综合考虑以上问题,构建新的面接触物理模型,并主要进行了承载机理的研究,为箔片气体轴承的优化设计和实际应用提供一定的借鉴。悬臂式多叶箔片径向轴承采用多个箔片一端固定,另一端顺次搭接在下一箔片上的结构。首先考虑了装配时的预紧力,建立装配后箔片和轴承的相对几何位置关系;引入柔度系数,考虑切向摩擦力,推导了箔片受力与变形之间的关系式;综合考虑箔片之间的面接触以及箔片与轴套内壁间的接触,根据接触法向约束法则,联立全部箔片的受力变形方程组,得到箔片所受各种力和接触点初始间隙的关系矩阵。本文运用加权残余法中的伽辽金法,对气体径向轴承的气体润滑雷诺方程进行离散化求解,将箔片弹性变形与气膜压力耦合迭代求解,设计整体气体弹性耦合求解算法流程。利用MATLAB进行编程计算,可以得到润滑气膜的压力分布、厚度分布,箔片受力、变形情况等计算结果。并对比验证了面接触计算模型的可靠性,分析了转轴转速以及箔片的各项基本尺寸安装参数对轴承的承载能力、起飞转速等性能的影响,以此优化轴承的设计。最后,进行了悬臂式多叶箔片径向轴承的实验研究。按照箔片径向轴承的特点,设计轴承实验平台和测量系统。本文采用一种简便的箔片成型装置用来加工处理箔片。进行了识别起飞转速实验和静态特性实验,观察箔片的磨损和接触状况,根据测得的数据,分析各项基本参数对轴承静态特性的影响。更多还原

【Abstract】 Flexible foil aerodynamic bearing technology,as an important part of gas lubrication technology,is a sensitive industrial technology.In aerospace and defense industry and other fields,flexible foil gas bearings as one of the core components,are widely used in fighter aircraft,high temperature gas turbines,cruise missiles,cryogenic cooling systems.Foil gas bearing has good development potential and application prospect in high-speed turbine because of its non-lubricating oil,low maintenance cost and strong environmental adaptability.There are few literatures about the cantilever foil journal bearing,and most researches on multi-leaf foil journal bearings assume that the foils are in line contact.There are many problems with the proposed face contact assumption.For example: the contact between the film and the sleeve is neglected,the tangential friction is neglected in the modeling process,and the initial pre-tightening force is neglected in the assembly of the foil.In view of the above problems,a new physical model of surface contact is constructed and the bearing mechanism is mainly studied,to provide some reference for the optimal design and practical application of foil gas bearings.Cantilever multi-leaf foil radial bearings using multiple foils fixed at one end,the other end in turn overlap in the next foil structure.Firstly,the pre-tightening force is taken into account and the relative geometrical position between the foil and the bearing after assembly is established.By introducing the flexibility coefficient and considering the tangential friction,the relation between stress and deformation of the foil is deduced.Considering the surface contact between the foil and the contact between the foil and the inner wall of the sleeve,according to the contact constraint law,the force-deformation equations of all the foils are combined to obtain the foil flexibility relation matrix.In this paper,the Galerkin method of weighted residual method is used to discretize the gas-lubricated Reynolds equation of gas radial bearings.The elastic deformation of the foil and the pressure of the gas film are iteratively solved.The whole process of gas-elastic coupling is solved.Using MATLAB to program and calculate,the pressure distribution,thickness distribution,stress and deformation of foil can be obtained.The reliability of the calculation model of surface contact was verified.The influence of the rotating speed of rotating shaft and the basic dimensions of foil on the bearing capacity and take-off speed were analyzed to optimize the bearing design.Finally,experiments are conducted to study the cantilever foil journal bearing.According to the characteristics of foil radial bearing,the bearing experiment platform and measuring system are designed.This article designed a convenient foil forming device for processing foil.The experiment of identifying the take-off speed and static characteristics was carried out.The wear and contact condition of the foil was observed.According to the measured data,the influence of the basic parameters on the static characteristics of the bearing was analyzed.更多还原