【作者】 叶燚玺；

【导师】 陈学东； 罗欣；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2010， 博士

【摘要】 超精密运动平台有别于传统的精密运动机构,后者多由接触式运动副和刚性结构所组成,摩擦、发热及振动传递等因素制约了这类机构结构的动力学特性,目前这类机构的运动精度只能达到微米级,无法满足诸如IC制造装备等运动精度达纳米级的需求。因此,以气浮支承取代机械接触式的运动副是超精密运动平台的主要结构特征,尽管与传统运动机构相比,超精密运动平台的动力学特性有显著改善,但气浮支承内部气流运动引起的振动仍不容忽视,是制约气浮运动平台定位精度提升的关键因素。针对这一问题,本文采用数值计算和物理实验相结合的方法,系统地研究了超精密运动平台中气浮支承的振动特性,内容和成果包括：1)利用气体润滑理论,建立了气浮气膜的三维力学模型,数值仿真和物理实验结果表明,建模精度较现有的二维模型有较大的提高；2)采用数值仿真方法,分析了气浮支承中压力腔形状、结构尺寸等结构因素和供气压力、气膜间隙等工艺参数对气旋的影响规律,并通过物理实验方法研究了不同条件下系统微振动的特性,阐明了气旋是引起系统微振动的主要因素；3)建立了气浮支承气锤振动的数学模型,采用物理实验方法,研究了压力腔形状与气浮支承气锤振动的内在关系,揭示了压力腔形状对气锤的影响规律,提出了气浮支承压力腔设计原则,为气浮支承系统的结构设计提供了理论指导；4)采用仿真和实验相结合的方法,分析了压力腔形状、节流器尺寸和工艺参数对气浮支承系统振动传递特性的影响规律,提出了一种气浮支承振动传递特性的实时调节方法。本文的研究揭示了气浮支承振动的产生机理,阐明了不同气浮支承结构对气旋和气锤的影响规律,提出了气浮支承系统动力学特性分析方法,为超精密气浮运动平台的设计和制造提供了理论依据。更多还原

【Abstract】 Ultra-precision motion stages, the core part of a wide range of precision manufacturing equipments, differentiate themselves from traditional motion mechanisms characterized of contacted motion pairs and rigid structures. It is well recognized that the limit precision of traditional motion stages can only achieve micron-level, far beyond the needs of nanometer level of motion precision required in some nano-manufacturing devices such as semiconductor lithography, due to serious issues such as friction, heat generation and vibration transmission phenomena. Therefore, in modern ultra-precision motion stages, aerostatic bearings are widely applied in place of traditional contact moving pairs, as a result, significantly improving dynamic performance of ultra-precision motion stages, in comparison with that of traditional motion stages. Nevertheless, vibrations induced by gas flowing in aerostatic bearing can still not be ignored, and it has become one of the major factors, which limit further improvement of motion precision of the stages. In this dissertation, aiming at this problem, the combinational methods of simulations and experiments are conducted to further investigate the vibration characteristics of aerostatic bearing. The content and achievement of this dissertation are as follows.1) A 3D mechanical model is built by applying the gas lubrication theory. The simulation and experimental results indicate that the accuracy of the proposed model has greatly been improved, comparing to that of the existing 2D model.2) The patterns of influence of the structure factors, such as shape and dimension of chambers, and the process parameters, such as gas supply pressure and gas film clearance, on the gas vortex in aerostatic bearing are analyzed by applying numerical simulation methods. The micro-vibration characteristics under different conditions are studied through a serial physical experiment. It is clarified that the gas vortex existing in aerostatic bearing is the major factor of the phenomenon of system micro-vibration.3) The intrinsic relationship between pressure chamber shapes of aerostatic bearings and pneumatic hammer phenomena has been studied based on physical experiments. The patterns of the influence of chamber shapes on the pneumatic hammer phenomena are revealed, and the design rules of chamber shapes in aerostatic bearings are established, which provide a theoretical guidance for the design of aerostatic bearings.4) Based on a combination of numerical analyses and physical experiments, the patterns of the influence of chamber shapes, orifice dimensions and condition parameters on the vibration transmission characteristics of aerostatic bearings are studied, and a method for real-time regulation of dynamical performance of aerostatic bearings is proposed.In general, in this dissertation, the vibration mechanisms of aerostatic bearings are revealed, and the patterns of the influences of bearing structures and operating conditions on the phenomena of the gas vortex and the pneumatic hammer are clarified, and the dynamics analysis methods of aerostatic bearings are proposed. The research results are believed to provide a theoretical basis for the design and manufacturing of ultra-precision motion stages.更多还原