Vacuum Pump

摘要

A vacuum pump is provided, which suppresses occurrence of a gas product in an exhaust side outlet of a thread groove and maintains pump performance over a long period. The vacuum pump includes inflow suppressing walls formed by widening greater an exhaust side end portion of ridge portions, extended along a gas exhaust direction on an outer circumferential surface of an inner circumference side stator, forward in a rotor rotating direction than an intake side end portion, the inflow suppressing walls suppressing retention of gas in exhaust side outlets of thread grooves engraved among the ridge portions.

主权项

1. A vacuum pump comprising a thread groove pump mechanism including: a rotor cylinder portion provided in a rotor rotatable in a predetermined rotating direction; a substantially cylindrical stator disposed beside the rotor cylinder portion via a gap coaxially with the rotor cylinder portion; a plurality of ridge portions extended along a gas exhaust direction on either an opposite surface of the stator opposed to the rotor cylinder portion or an opposite surface of the rotor cylinder portion opposed to the stator; and a thread groove engraved between the plurality of ridge portions, the vacuum pump transferring gas in the thread groove from an intake side to an exhaust side in the gas exhaust direction, wherein
the vacuum pump includes gas retention suppressing means for suppressing retention of a gas in an exhaust side outlet of the thread groove.