节流粘性强化下气浮支承刚度增强及气锤自激振动抑制机理研究

Facing the requirement of high stiffness and high reliability for special material processing equipment in major precision physics experiments, there exists a serious problem that the orifice compensated aerostatic bearings are prone to pneumatic hammer with the increasing stiffness. To solve the key problem, a new idea is proposed, which can enhance the stiffness and overcome the phenomenon of pneumatic hammer by increasing restriction viscosity. Based on the idea, the aerostatic bearing with viscous-inertial coupling restrictors is designed. Firstly, to reveal the effect of enhancing restriction viscosity, the influence of interaction between the viscous flow and the inertial flow in the viscous-inertial coupling restrictor on the microscopic flow field is studied by means of numerical simulation and experimental analysis. Secondly, a fluid-solid coupling model of aerostatic bearing with restriction viscosity enhanced is established, and the viscous-inertial flow matching characteristics in restrictor and gas film are also analyzed. Then the mechanism of the enhancing restriction viscosity for the stiffness enhancement and self- excited vibration suppression is explored. Finally, the strategy are presented to improve the stiffness and suppress the self-excited vibration, and the experimental study of aerostatic bearing with viscous-inertial coupling restrictor is also carried out. The research results of this project will provide theoretical and technical support for improving the performance of special ultra-precision machining equipment, and have positive significance for enriching the theory of fluid lubrication.

面向重大精密物理实验对特材加工装备气浮支承高刚度、高可靠性的要求，针对传统小孔节流气浮支承刚度增强容易产生气锤自激振动失稳的难题，提出增强节流粘性效应，实现小孔节流气浮支承刚度提升的同时抑制气锤自激振动的思想。在此基础上，设计一种新型的粘-惯性耦合节流气浮支承结构。首先，采用数值模拟与实验分析的方法，研究粘-惯性耦合节流中气体粘性流动与惯性流动的相互作用对微观流场流动状态的影响规律，揭示节流粘性强化效应作用机理；然后，建立节流粘性强化下气浮支承系统流固耦合模型，探索节流器与润滑气膜内粘-惯性流动匹配特性，探明节流粘性强化下气锤自激振动抑制机理。最后，提出节流粘性强化下气浮支承刚度增强与自激振动抑制策略，并开展粘-惯性耦合节流气浮支承实验研究，实现气浮支承的服役性能提升。本项目研究成果将为提高特材超精密加工装备性能提供理论与技术支撑，对丰富流体润滑理论具有积极的意义。

面向重大精密物理实验对特材加工装备气浮支承高刚度、高可靠性的要求，针对传统小孔节流气浮支承刚度增强容易产生气锤自激振动失稳的难题，提出了增强节流粘性效应，实现小孔节流气浮支承刚度提升的同时抑制气锤自激振动的思想。本项目首先研究并揭示了粘-惯性耦合节流节流强化作用机理。然后建立了粘-惯性耦合节流静压气浮支承数学模型，研究了耦合节流器结构参数对支承微振动特性影响规律，结果表明节流粘性强化效应能够减小气浮支承的微振动。最后，设计并制造了粘-惯性耦合节流静压气浮轴承，研究并揭示了粘-惯性耦合节流对静压气浮支承承载力和刚度影响规律。结果显示，相对小孔节流，粘-惯性耦合节流气浮轴承能在较大的气膜间隙下实现较大承载能力和刚度，并实验验证了理论分析结果。本项目研究成果将为提高特材超精密加工装备性能提供理论与技术支撑，对丰富流体润滑理论具有积极的意义。