DRIVE MECHANISM HAVING A GAS BEARING OPERABLE UNDER A NEGATIVE PRESSURE ENVIRONMENT

摘要

PURPOSE: To move and position a movable portion with higher accuracy by arranging the movable portion in the space under the evacuated environment an then driving the movable portion through connection with a gas bearing. CONSTITUTION: A movable portion 10 is placed on a predetermined work bench W and this movable portion 10 and a gas bearing 20 are arranged in the space C under the evacuated environment. The movable portion 10 is connected with the gas bearing 20 and this gas bearing 20 supplies the gas P to the space between the movable portion 10 and opposing surface Wa with a driver 30 to float the movable portion 10 from the work bench W to assure the movement of the movable portion on the work bench W. That is, the gas bearing 20 supplies the gas P to the very small space between the opposing surface Wa and movable portion 10 to keep the small space in the higher pressure condition than the evacuated space. Thereby, the movable portion 10 can be floated from the opposing surface Wa using the higher pressure gas as the medium.