PURPOSE: To prevent fluid from leakage to the outside through a space between a drive shaft and a casing by affording communication between an empty chamber surrounded by the rotor end face at the drive shaft of a rotor projecting from the casing and the inside wall of the casing and the intake side of a pump.
CONSTITUTION: An empty chamber 44 surrounded by the rotor 5 end face 6 at the side of a drive shaft 6a of a rotor 5 projecting from a casing 1 and the inside wall of the casing 1 communicates to an intake path 43a through a communicating hole 45. Thus, gas leaking from the rotor 5 end face is recovered to the intake side of pump by the negative pressure in the intake path 43a. Thus, the gas does not leak to the outside through a space between the drive shaft 6a and the casing 1.
MATSUMOTO OSAMU
KINOSHITA MASAKAZU
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