To prevent an accident such as stopping of a rotor when process gas infiltrates and condenses into a screw seal part for shaft seal of the gas in a molecular pump having a thread groove pump part.
A composite molecular pump 1 has a first thread groove pump S1 formed on the outer peripheral side of the rotor 3b of the thread groove pump part S and a second thread groove pump S2 formed on the inner peripheral side of the rotor 3b, and is formed as a structure for directly joining an inside stator 5 of the second thread groove pump S2 to an outside stator 4 of the first thread groove pump S1 by screw-fastening, and is formed as a structure for thermally insulating the outside and inside stators from these fixing parts by connecting the outside stator 4 by interposing heat insulating materials 8a and 8b in the fixing parts of an outside casing 7 and a pump base 9. A screw seal part 5b is adjacently recessed in a thread groove 5a recessed on an outer peripheral surface opposed to the rotor 3b of the inside stator 5.
OBAYASHI TETSUO
YAMATO YUKIRO
| JPS61145394A | 1986-07-03 | |||
| JPH02149798A | 1990-06-08 | |||
| JP2002180988A | 2002-06-26 | |||
| JPH09310696A | 1997-12-02 |
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