空气静压主轴多场耦合动力学分析及动平衡精度提升方法研究

Aerostatic spindle is one of the core components of an ultra-precision machine tool. Due to the limitation of current balancing accuracy, the aerostatic spindle has not been fully taken advantage of and works at low rotating speeds for a long time, which limits the efficiency improvement of ultra-precision machining. This project will study the basic theories and key technologies for the high-accuracy balancing of aerostatic spindles from the perspective of dynamic analysis. Firstly, the dynamic modeling theory of aerostatic spindles is studied with consideration of coupling effects in gas-solid-thermal multi-physical field, and the mechanism and transfer law of unbalanced vibration responses are revealed. Secondly, the method of amplitude amplification and energy enhancement for the weak unbalance vibration response is studied based on the resonance principle, which can provide theoretical proofs for lifting the balance accuracy. Finally, this project devotes to investigate a new approach for improving the balancing accuracy by a large margin based on coupling/decoupling intelligent structures, which will break through the technique bottleneck that the current dynamic balancing methods largely depend on the sensitivity of vibration sensors. A test rig will be set up for balance accuracy lifting of aerostatic spindles, and dynamic balancing and ultra-precision machining tests will be carried out to complete experimental and engineering validation of theoretical methods. The research results of this project will effectively improve the dynamic balancing accuracy of aerostatic spindles, which will further increase the spindle speed and promote the development of ultra-precision machining technology. Thus, this project is of great theoretical significance and application value.

空气静压主轴是超精密机床的核心部件之一，在当前动平衡精度和水平的限制下，长期处于“高速低用”的状态，制约着超精密加工效率的提高。本项目从动力学角度研究空气静压主轴高精度动平衡的基础理论和关键技术。首先，建立气－固－热多物理场耦合作用下的空气静压主轴动力学模型，揭示不平衡振动响应的产生机理和传递规律。其次，研究基于同频共振原理的微弱不平衡振动响应幅值放大与能量增强方法，为动平衡精度提升提供理论依据。最后，研究基于智能结构耦合/解耦的动平衡精度大幅度提升方法，突破现有动平衡方法严重依赖振动传感器灵敏度的瓶颈，实现空气静压主轴高精度动平衡。搭建空气静压主轴动平衡精度提升试验平台，开展动平衡和超精密加工试验，完成理论方法的试验与工程原理验证。项目的研究成果将有效提升空气静压主轴的动平衡精度，从而提高主轴的工作转速并推动超精密高速高效加工技术的发展，具有重要的理论意义和应用价值。

空气静压主轴是超精密机床的核心部件之一，在当前动平衡精度和水平的限制下，长期处于“高速低用”的状态，制约着超精密加工效率的提高。本项目从动力学角度研究空气静压主轴高精度动平衡的基础理论和关键技术。在“空气静压主轴动力学建模理论”方面，提出了转子不对中条件下的空气静压径向轴承、止推轴承的动力学建模方法，系统分析了空气轴承在不同偏心率、转速下其动态系数随倾角的变化规律；提出了考虑转子倾斜运动的5自由度空气轴承-转子-刀具耦合系统动力学建模方法，系统研究了转子的弹性变形与空气轴承动力学特性之间的动态耦合作用，为不平衡振动响应机理分析奠定基础。在“微弱不平衡振动响应机理分析及放大方法”方面，定量分析了不平衡质量对空气静压主轴振动特性的影响，提出了基于同频共振原理的微弱不平衡振动响应幅值放大与能量增强方法，为空气静压主轴动平衡精度提升提供理论依据。在“动平衡精度大幅度提升方法”方面，设计并制作了具有刚性和柔性状态，且柔性状态下刚度连续可调的变刚度支承结构，开展变刚度支承结构的仿真和实验模态分析，验证了变刚度放大不平衡振动响应的可行性和安全性；建立了空气静压主轴－智能结构有限元模型，基于该模型研究智能结构动力学参数调节方法，实现不同转速下不平衡振动响应放大；提出了基于智能结构耦合/解耦的动平衡精度大幅度提升方法，突破现有动平衡方法严重依赖振动传感器灵敏度的瓶颈，实现了空气静压主轴高精度动平衡。. 研究成果在Tribology International，ASME Transactions等国内外期刊发表论文19篇，其中SCI检索16篇，在国际生产工程科学院（CIRP）年会做学术报告3次；授权国家发明专利3项，获陕西省高等学校科学技术一等奖1项（2020）；项目负责人获批优秀青年科学基金，培养博士、硕士等人才8名。