文档介绍：南京航空航天大学
硕士学位论文
弹性波箔动压径向气体轴承的理论分析与实验设计
姓名:徐国庆
申请学位级别:硕士
专业:机械设计及理论
指导教师:马希直
20080101
南京航空航天大学硕士学位论文
摘要
弹性波箔动压径向气体轴承是一种新型的支承元件膨胀机等高速旋转设备上,在理论和应用方面都进行了较为深入地研
究。而国内目前主要处在理论探索阶段,对轴承性能的研究虽有些相关报告,
但系统性的理论分析还没有形成,特别是在应用方面还没有成熟的产品出现。
该类轴承的箔片弹性及阻尼对轴承工作性能的影响比较复杂,精确建模困难较
大。
本论文主要完成了以下几个方面的工作。首先分析了弹性箔片在载荷作用
下的变形规律,得到箔片变形的计算模型。然后建立了弹性波箔轴承的热流体
动力模型,应用数值方法并编程计算,得到波箔轴承压力、膜厚分布规律,并
讨论了其与偏心率、长径比等影响参数之间变化关系,比较了刚性轴承与波箔
轴承在压力、膜厚分布上的差异,求解了轴承工作区的气膜温度场。在此基础
上建立了动特性模型,得到轴承气膜刚度、阻尼与偏心率、长径比、轴承数之
间的关系。最后为进行实验验证,设计了箔片加工模具,制作了部分轴承零件,
设计了轴承测试实验台。
本论文的研究工作为进一步对该类轴承进行深入的理论分析和实验测试做
了一定的基础工作,希望为今后波箔轴承及相近弹性轴承的研究提供一定的借
鉴作用。
关键词:波箔,平箔,动压气体轴承,弹性变形,刚度阻尼系数
i
弹性波箔动压径向气体轴承的理论分析与实验设计
Abstract
Bump foil journal bearing is a new kind of ponents. The
bearing has been widely used in high-speed rotational machinery such as turbo
expander etc. The study on the performance of the bearing has a long history.
However, there evenly are lots of problems on the theoretical study and practical use
of the bearing today, Especially on the building of exact model because it is difficult
to take into account the influence of elastic and damping on the performance of
bearings.
This thesis presents a research on bump foil bearing and the detail is as follows.
Firstly, the calculation model of the deflection of bump foil and top foil under
uniform press of the air film in the bearing is established by the use of elastic theory.
Secondly, the elastic thermal aerodynamic lubrication model is built up, and the
program used to solve the model by numerical methods is developed. The
distributions of pressure and thickness of the air film are obtained and the temperature
distributing of the film is given too. The changes of bearing performance with
eccentricity, length-diameter ratio are discussed. At the same time, parisons of
the pressure and air film thickness distributions between rigid bearings and elastic
bearings are shown. Thirdly, the relationship bet