| 摘要 |
PURPOSE:To need no sealing system any more by external purge gas by installing a throttle system just in front of the discharge port of a vacuum pump, and also a duct leading through a sealing section positioned between a bearing and the duct, and the upper course section of the throttle system. CONSTITUTION:An orifice 11 is set up at the upstream side of the discharge port 13 of a vacuum pump, and a purge gas duct 13 leading through a discharge duct 12 on the upstream side of the orifice 11 and a seal 10 is installed. With this constitution, gas introduced to a sealing section flows into a dust side and a bearing side, preventing lubricant oil vapor of the bearing section from entering the duct side, and thus purge gas from outside is not necessary.
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