multistage vacuum pump trockenverdichtende a roots rotor and a schraubenrotor

摘要

Disclosed is a dry vacuum pump (1) for evacuating a processing chamber in semiconductor or display manufacturing device, or for evacuating the gaseous substances and/or the byproducts generated in process chamber. The dry vacuum pump does not need a partition wall between a roots rotor (14) and a screw rotor (18). In the dry vacuum pump, a space (16, 16') is formed on the connecting portion to the roots rotor (14) among through the under sides of the roots rotor (14) and the screw rotor (18) to stay the object substance thereon.