Improving the Rotational Stiffness of Compact Aerostatic Guideway by Micro-Structures Optimization

Abstract

To meet the requirement for the exact computation of rotational stiffness, this paper puts forward a mesh adaptation based analysis method for a compact multi-throttle aerostatic guideway and its constituent micro-structure. Contrary to previous methods that substituted or even ignored them, the dimensionless thickness pertaining to the depth of the micro-structure is restored and incorporated into each computational grids. The mesh adaptation procedures accept the dimensionless thickness as an intermediate variable for the target mesh and apply local modifications to adapt the mesh to match the specified size. Then, the varying regularity of rotational stiffness by micro-structures can be studied by k-ε turbulence model when tilt. The tilt angle, although small, leads to a wedge-shaped film and then an uneven pressure distribution which has been also taken into consideration. Guided by the mesh adaptation method, a vertical compact guideway with high rotational stiffness of 7.22 × 103 Nm/rad is designed and manufactured for photolithography. The experiments verify its practical accuracy and effectiveness.

Keywords

• Compact aerostatic guideway
• mesh adaptation
• multi-throttle
• rotational stiffness