| 摘要 |
PURPOSE:To obtain a small-sized and lightweight cryopump by removing a balance weight by installing a bellows on the opposite side and vacuum-absorbing the inside of the bellows, when the cryopump connected by a vibrationproof bellows is vacuum-absorbed. CONSTITUTION:A flange 24b is formed at the lower edge opened-port part of a casing 24a which accommodates the piston 21c and the cylinder 21a of a cryopump and is equipped with a rough suction port 24c. The part between the upper edge of the driving part 21 of the cryopump and the flange 24b is closely sealed by a bellows 25a which can be vacuum-exhausted, and the flange 24b and the flange 28 are fixed by an arbitray number of rigid supporting beams 29. The driving part 21b can be moved vertically in the supporting beams 29, and the bellows 25b which can be vacuum-exhausted is connected in sealed form between the driving part 21b and the flange 28 and vacuum-absorbed from a valve 32 or allowed to communicate to the inside of the bellows 25a, and the suction force on the bellows 25a side is offset by the weight of the driving part 25a and the suction force inside the bellows 25b. |
