| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas bearing capable of preventing a gas leakage into a vacuum chamber even when moving a vacuum device. SOLUTION: High pressure (about 4 atmospheric pressure) air or nitrogen is blown in between a fixed block 1 and a moving block 2b through a high pressure nozzle part 2a to support a load between a fixed part and a moving part by the pressure and reduce a friction force when moving. Since a clearance 4 between a block 3 and the fixed block 1 is very small, high pressure gas does not enter the vacuum chamber 6 easily through the clearance. Furthermore, bellows are provided on the block 3 to exhaust high pressure gas through between them by an exhaust system. Ceramic made of alumina having purity of 99.5% is used as a block 6. Since the ceramic scarcely has void part, a leakage of air and nitrogen is greatly reduced even if an area for absorbing air and nitrogen is reduced and a movable part moves.
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