| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum pump that can restrain a reaction product from depositing on an inner screw stator.SOLUTION: A screw stator 60 comprises an outer screw stator 41 and an inner screw stator 51 that are thermally connected. In a rotor lower cylindrical part 4B, gas passage communication opening parts 76 that make the side of the outer screw stator 41 communicate with the side of the inner screw stator 51 are formed. The outer screw stator 41 and the inner screw stator 51 are thermally insulated from an upper part of a base 13 and a center cylindrical part 14 by heat insulating materials 70 respectively. In a lower part of the base 13, a base lower cooling pipe 74 is provided. |
