Deformation and flying height orbit of glass sheets on aerostatic porous bearing guides

Handling devices have been developed for liquid crystal display fabrication that are equipped with aerostatic porous bearing pads to feed large glass sheets while supporting them with compressed air in a non-contact state. The deformation behavior and the orbit of the flying height of glass sheets on porous bearing pads during the feeding process were investigated using the compressible Reynolds equation and Timoshenkoʹs thin film theory. Theoretical and experimental results showed that glass sheets are easily deformed by the pressure distribution in the air film and that they tilt easily on the bearing pad during the feeding. The results also showed that the hole pitch for air suction and the interval between bearing pads arranged next to each other should be shorter to achieve more stable feeding of the glass sheets with a constant flying height.