SEALING DEVICE FOR ROTARY VACUUM PUMP

摘要

PURPOSE:To eliminate the contamination due to the lubricant and to maintain the clean interior of a pump chamber by providing a cutoil board between the pump chamber and a lubricant chamber while further providing a sealing device requiring no lubricant between the cutoil board chamber and the pump chamber. CONSTITUTION:A rotary vacuum pump contains a rotor 3 associated with a rotary shaft rotatably in a pump chamber 1 thereof where the rotary shaft 2 penetrates through a partition wall 11 and a lubricant chamber 5 and extends to the outside so as to be coupled with a drive motor. In such arrangement, a bearing 4 is provided on said partition all 11 while contacting with the lubricant chamber 5 and a cutoil board chamber 12 is provided at the intermediate section against the pump chamber 1. A cutoil board 13 is fixed in said chamber 12 with the tubular section thereof fitting to the rotary shaft 2. Furthermore, an opening 14a of an oil return path 14 communicating with the lubricant chamber 5 is formed in the bottom of said chamber 12. A hermetic seal 16 requiring no lubricant 12. A hermetic seal 16 requiring no lubricant is fixed to the pump chamber 4 side of said chamber 12 so as to slide against the circumferential face if a shaft sleeve 17 fitted the rotary shaft 2.