微结构参数对静压气体导轨节流系数和转动刚度的影响

The small multi-throttle aerostatic guideway is the critical component to solve the high precision and high acceleration motion demand of the lithography machine. Generally, microstructures such as recesses and grooves are added to the working surface to improve the capacity characteristics. However, the influence of microstructure parameters on mechanical properties, especially the rotational stiffness of the guideway is not clear enough. In order to establish the analytical expression with modified throttling coefficient, adaptive finite volume method is used to study the influence of four kinds of microstructure parameters. Based on the principle of highest rotational stiffness, considering capacity and stiffness as well, the selecting expressions of microstructure parameters are summarized, which can be directly used for guiding design work. Taking the guideway in the variable-slit system of the photolithography machine as an example, the modified throttling coefficient function and the selecting method of microstructure parameters proposed are used to design of the small multi-throttle aerostatic guideway. The experiment shows that the rotational rigidity of the guide reaches 10.3 × 10³ N•m /rad, and the accuracy and effectiveness of the method are verified.