分区激励的多模超声轴承悬浮承载机理及稳态控制研究

Lifting of load-carrying capacity and high-speed steady state control are the key technical problems to be solved urgently in the engineering and industrialization of ultrasonic bearings. This project takes the multi-mode ultrasonic bearing by zonal excitation as the research object, takes the electro-acoustic conversion efficiency and suspension bearing capacity as the optimization objective, and adopts the methods of theoretical analysis, numerical simulation and test experiment to carry out the research on the structure and dynamic parameters’ optimization, impedance matching and driving characteristics of the ultrasonic bearing. Based on the non-linear acoustics and fluid dynamics theory, the ultrasonic bearing’s radial static and dynamic mechanisms under different driving modes are studied with the aid of multi-physical coupled-field simulation and experimental methods. The influence laws of the driving parameters, working modes, gas characteristics, radial clearance, and the work environment factors on the levitation capacity of the ultrasonic bearing are revealed, which guides the exploration of the methods for improving the bearing’s suspension capacity. The real-time monitoring system of bearing operation state is developed, and the fault diagnosis and on-line stability identification methods of bearing-rotor system are investigated. Then the failure control strategy and stability control rules of high-speed bearing operation are formulated. A deep learning method was constructed, and a large number of closed-loop control experiments based on online identification are conducted to improve the bearing’s control strategy and procedure database, which will contribute to the self-adaptive ability of the ultrasonic bearing. The research on this project will accelerate the engineering application of multi-modal ultrasonic bearings by zoning excitation.

悬浮承载力的提升和高速稳态控制是超声轴承走向工程化和产业化亟待解决的关键技术问题。本项目以分区激励的多模超声轴承为研究对象，以电声转换效率和悬浮承载力为优化目标，采用理论分析、数值模拟和测试实验相结合的方法，开展超声轴承结构与动力参数优化、阻抗匹配及驱动特性研究。基于非线性声学和流体动力学理论，借助多物理场耦合仿真及实验手段，研究多驱动模式下分区激励超声轴承的静态和动态径向承载机理，揭示驱动参数、工作模态、气体特性、径向游隙、工作环境等因素对轴承悬浮承载力的影响规律，探索提升轴承悬浮承载力的措施。研制轴承运行状态实时监测系统，研究轴承-转子系统故障诊断与稳定性在线辨识方法，制定轴承高速运行失效控制策略和稳定控制规程；基于深度学习算法，开展大量基于在线辨识的闭环控制试验，完善轴承控制策略与规程数据库，提高轴承失效控制和稳态控制的自主能力。本项目研究可加速分区激励的多模超声轴承的工程化应用。

制造基础技术与关键基础件是装备制造业赖以生存和发展的基础，其水平直接决定着重大装备和主机产品的性能、质量和可靠性。轴承作为组成机器的极为重要的基础件，依托基础前沿技术的新型轴承结构的研发，可为我国高端智能装备制造的转型升级和可持续发展提供强有力的技术支撑。本项目基于压电驱动原理和超声波近场悬浮技术，提出了一种分区激励的多模超声轴承结构。以电声转换效率和悬浮承载力为优化目标，采用理论分析、数值模拟和测试实验相结合的方法，开展超声轴承结构与动力参数优化、阻抗匹配及驱动特性研究。基于声辐射压理论和理想气体热力学理论，建立了单轴悬浮超声轴承的径向悬浮力学模型，并通过实验进行了验证，为轴承结构和性能设计奠定了基础。考虑气体惯性、表面形貌效应、稀薄效应和边界效应，建立了基于修正雷诺方程的多轴支承超声悬浮轴承力学模型，获得了轴承驱动参数、介质黏度、轴承间隙和环境温湿度等因素对轴承径向悬浮力的影响规律。研制了分区激励的多轴支承超声悬浮轴承原理样机，开展了轴承摩擦特性和高速运行稳定性实验，验证了转子转速、轴承载荷和间隙对轴承高速运行稳定性的影响规律。超声轴承的悬浮理论与实验研究可加速超声轴承的工程化应用进程，推动高端动力装备朝高性能、智能化和绿色化方向发展。