PURPOSE: To always provide a stable shaft seal effect, enhance performance in a high vacuum region, and facilitate maintenance of high vacuum even when outside shaft sealing pressure water is not available.
CONSTITUTION: An impeller 30 is eccentrically provided in a cylindrical casing 21. Because of actuation of a liquid seal ring 7 formed in the casing 21 due to rotation of the impeller 30, gas is sucked from a suction port 23 of a casing side-plate 22 via a suction chamber 26 inside a casing cover 25, and discharged from a discharge port via a discharge chamber of the casing cover 25. In the casing cover 25, besides the suction chamber 26 and the discharge chamber a pressure chamber 28 having an opening 29 at a dead point part of the casing 21 is formed to pass a part of liquid film pressure water via the pressure chamber 28 to a seal water ring 10a of a shaft seal part 10 so that stable shaft seal effect can be always obtained.
JPS54126109U | 1979-09-03 | |||
JPS5372807U | 1978-06-17 | |||
JPS61167196A | 1986-07-28 |