超高转速空气静压电主轴特性分析与实验研究

发布时间：2018-09-17 13:40

【摘要】：超高转速空气静压电主轴是实现高精和高效切削的主体之一,是高端加工机床的核心功能部件,以气浮支承和电磁直接驱动为典型结构特征,其综合性能受到电、磁、气、固、热等多物理场的影响。本文面向我国微切削加工机床关键部件的重大应用需求,围绕超高转速气浮轴承的工作机理及性能增强机制、多物理场耦合作用下空气静压电主轴系统的稳态特性这两个关键科学间题,从分析方法和关键技术层面,通过多学科交叉融合,分析空气静压轴承在超高转速下的综合特性,揭示人字槽微结构对气浮径向轴承性能的作用规律,研究多物理场耦合作用下电主轴系统的稳态特性,为我国高端加工装备核心部件的自主研发提供基础理论和关键技术支持。针对超高转速空气静压电主轴高速、精密和稳定运行的工作需求,分析电主轴系统涉及的关键技术,提出超高转速空气静压电主轴设计基本原则,确定超高转速空气静压电主轴核心部件以及整机的结构方案。采用有限元法数值求解非线性可压缩雷诺方程,推导含有速度项的雷诺方程有限元形式,提出有限元数值求解改进方法；提出基于CFD的超高转速气浮轴承微结构特性分析方法和气浮电主轴系统多物理场耦合集成仿真分析方法,为超高转速空气静压电主轴系统的特性分析奠定理论基础。为了研究空气静压轴承在不同转速和偏心率工况下的工作机理,基于有限元法数值求解非线性可压缩雷诺方程,开发空气静压径向轴承和止推轴承性能分析程序,揭示静压效应、动压效应和动静压混合效应对超高转速空气静压径向轴承性能的作用机理,分析空气静压径向轴承和止推轴承的结构参数对轴承性能的影响规律。建立计算流体动力学流场仿真模型,分析超高转速工况下空气静压轴承节流孔气腔构型和均压槽等微小结构对轴承性能的影响规律。提出锥面止推轴承的新型轴承构型,分析锥面止推轴承的流场特性并辨识其性能参数,通过与平面止推轴承性能对比表明,锥形结构提高了空气静压止推轴承的综合性能。最后,通过实验验证了气浮轴承CFD仿真模型的有效性。为了研究人字槽微结构对超高转速气浮径向轴承的作用规律,首先揭示人字槽微结构对气浮径向轴承的作用机理,提出人字槽微结构的设计基本原则。其次,基于气体润滑雷诺方程有限元数值求解方法,建立人字槽微结构性能分析数学模型,揭示不同工况下人字槽微结构几何参数对动压径向轴承和动静压混合径向轴承性能的作用规律。再次,基于正交数组试验设计方法,通过灵敏度分析辨识人字槽微结构几何参数对动压径向轴承和动静压混合径向轴承承载能力的贡献程度。最后,研制11组尺寸参数的人字槽微结构,通过实验研究不同转速工况下人字槽微结构对电主轴系统径向跳动的影响规律,结果表明人字槽微结构能够有效降低电主轴系统的径向跳动。为了研究超高转速空气静压电主轴系统在多物理场耦合作用下的稳态特性,分析电主轴系统各物理场之间的相互作用关系,研究空气静压电主轴系统多物理场分析中的电-磁-气-固-热各物理场子模型,基于Isight软件建立超高转速空气静压电主轴系统多物理场集成仿真模型,分析多物理场耦合作用下电主轴系统稳态温度场、结构热变形、气浮轴承流场特性和轴芯的动力学特性等。通过实验研究空气静压电主轴系统的温度场、结构热变形、耗气量、轴芯自由模态、电主轴系统振动等特性,验证了本文建立的超高转速空气静压电主轴系统多物理场集成仿真模型的有效性。
[Abstract]:Ultra-high speed Aerostatic Spindle is one of the main parts to achieve high precision and high efficiency cutting. It is the core functional components of high-end machining machine tools. Air bearing and electromagnetic direct drive are typical structural features. Its comprehensive performance is affected by many physical fields such as electricity, magnetism, gas, solid and heat. Major application requirements, focusing on the working mechanism and performance enhancement mechanism of super-high speed air bearing, and the steady-state characteristics of Aerostatic Spindle System under the coupling of multi-physical fields, the synthesis of aerostatic bearing under super-high speed is analyzed from the analysis method and key technical level through multi-disciplinary integration. This paper reveals the effect of herringbone groove microstructure on the performance of air bearing, studies the steady-state characteristics of motorized spindle system under multi-physical field coupling, and provides the basic theory and key technology support for the independent research and development of core components of high-end processing equipment in China. This paper analyzes the key technologies involved in the motorized spindle system, puts forward the basic design principles of the ultra-high speed aerostatic spindle, determines the core components of the ultra-high speed Aerostatic Spindle and the structural scheme of the whole machine. The finite element method is used to improve the finite element method, and the CFD-based microstructural analysis method of the ultra-high speed air bearing and the multi-physical field coupling integrated simulation method of the air-floated electric spindle system are proposed to lay a theoretical foundation for the analysis of the characteristics of the ultra-high speed Air-static piezoelectric spindle system. Based on the nonlinear compressible Reynolds equation, the performance analysis program of aerostatic journal bearings and thrust bearings is developed. The mechanism of hydrostatic effect, hydrodynamic effect and hydrodynamic-hydrostatic mixing effect on the performance of aerostatic journal bearings with super-high rotational speed is revealed, and the effect of air on the performance of aerostatic journal bearings with super-high rotational speed is analyzed. The influence of structural parameters of aerostatic journal bearings and thrust bearings on the performance of bearings is studied. A computational fluid dynamics flow field simulation model is established to analyze the influence of the configurations of throttle cavities and pressure-sharing grooves of aerostatic bearings on the performance of bearings at super-high speed. The flow field characteristics of the tapered thrust bearing are analyzed and its performance parameters are identified. The comparison with the plane thrust bearing shows that the tapered structure improves the comprehensive performance of the aerostatic thrust bearing. Firstly, the action mechanism of herringbone groove microstructure on air bearing is revealed, and the basic design principle of herringbone groove microstructure is put forward. Secondly, based on the finite element numerical solution method of Reynolds equation, a mathematical model of herringbone groove microstructure performance analysis is established to reveal the geometric parameters of herringbone groove microstructure under different working conditions. Thirdly, based on the orthogonal array design method, the contribution of herringbone groove geometric parameters to the bearing capacity of hydrodynamic journal bearings and hybrid journal bearings is identified by sensitivity analysis. Finally, 11 groups of herringbone groove Micro-Parameters are developed. The effect of herringbone groove microstructure on radial runout of motorized spindle system under different rotational speeds is studied experimentally. The results show that herringbone groove microstructure can effectively reduce radial runout of motorized spindle system. The interaction among the physical fields of the spindle system is studied. The electro-magnetic-gas-solid-thermal physical field models in the multi-physical field analysis of the Aerostatic Spindle system are studied. Based on Isight software, the multi-physical field integrated simulation model of the ultra-high speed Aerostatic Spindle System is established. The steady-state temperature of the spindle system under the coupling of multi-physical fields is analyzed. The temperature field, thermal deformation of the structure, flow field characteristics of the air bearing and dynamic characteristics of the spindle core are studied experimentally. The temperature field, thermal deformation of the structure, gas consumption, free mode of the spindle core and vibration of the motorized spindle system are studied. The multi-physical field integrated simulation of the ultra-high speed air static piezoelectric spindle system is validated. The validity of the model.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG502.3

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