Research On Enhanced Mechanism Of Dynamic Stiffness For Piezoelectric Active Control Aerostatic Bearings

Aerostatic bearings are the key components of ultra-precision manufacturing equipment, due to the merits of near-zero friction, low heat generation and vibration isolation,they have been wildly used in state-of-the-art manufacturing equipment such as ultra-precision machine tools. However, improving the bearing capacity and dynamic stiffness is the core demand of ultra-precision machining. Usually, researchers improve the dynamic stiffness of aerostatic bearing by improving pressure, thickness of gas film, optimizing structure, the paper tried to use the array type piezoelectric to change the shape of gas film, achieving the improvement of dynamic stiffness and bearing capacity. For this, the paper carried out the research on the key issue about enhanced mechanism of bearing capacity and dynamic stiffness of non-uniform gas film.In order to research enhanced mechanism of dynamic stiffness for piezoelectric active aerostatic bearings, the paper mainly carried out the following work: Mechanical model of the steady gas film and non-uniform gas film structure model is established. Using the fluid simulation software for static simulation of gas film, to analyze the change of the bearing capacity and stiffness of non-uniform gas film compare with homogeneous gas film, to clarify the influence of piezoelectric constant driving voltage on the bearing capacity and stiffness. Designing the aerostatic bearing experiment platform, carrying out the static load experiment. The dynamic stiffness of non-uniform gas film is obtained by using the perturbation method, which can analyze dynamic stiffness characteristic of gas Using CFD dynamic grid technology to carry out the dynamic simulation of non-uniform gas film, to clarify the influence of the frequency and amplitude of dynamic changed driving voltage on the dynamic stiffness. Designing the experimental project of dynamic stiffness, carrying out the dynamic stiffness experiment.Through the above research, the paper revealed the rule of bearing capacity and stiffness of non-uniform gas film for different shape, clarified the mechanism of the array type piezoelectric changing the gas film shape and improving dynamic stiffness, which afforded theoretical foundation and technical support for the design of high performance bearing parts.