| 摘要 |
PROBLEM TO BE SOLVED: To realize a vacuum device having rotary resistance fewer than that in the case of only a magnetic fluid seal and more economical than the vacuum device of only differential exhaust system. SOLUTION: In a vacuum device to drive a spindle 1 extending into a vacuum chamber from the atmospheric pressure side, a sealing device to close a gap around the spindle 1 extending over the vacuum chamber and atmospheric pressure side is provided. This sealing device has a magnetic fluid seal 30 disposed in the vacuum chamber side, while a differential chamber 50 for low vacuum is formed on the atmospheric pressure side. |
