JP2019039396A5 - - Google Patents

Claims (1)

A pair of parallel extending rotor shafts each having a rotor attached thereto;
A pump chamber containing the rotor and the rotor shaft;
A gear chamber that is disposed adjacent to the pump chamber via a partition wall and that houses a gear train that transmits rotation between the rotor shafts;
Shaft end portions of the rotor shafts extending from the pump chamber into the gear chamber through a pair of shaft holes formed in the partition wall;
A shaft seal that seals between the shaft hole and the shaft end;
A vent passage provided on the partition wall, the air passage having a first opening end that opens to a portion on the gear chamber side on an inner peripheral surface of the shaft hole and a second opening end that opens to a portion on the shaft seal side; ,
A pressure damper first damper chamber provided on the first opening end side in the air passage and a pressure damper second damper chamber provided on the second opening end side;
An orifice provided in a passage portion between the first and second damper chambers in the air passage;
A dry vacuum pump having a bearing that supports the shaft end portion at a position closer to the gear chamber than the first opening end of the air passage in the shaft hole.