Vacuum pump

Abstract

A vacuum pump that includes: an outer cylinder having an inlet port and an outlet port; a rotor shaft rotationally supported inside the outer cylinder; rotor blades in multiple stages, the rotor blades being rotatable together with the rotor shaft; stator blades in multiple stages, the stator blades being fixed to the outer cylinder and located respectively between the rotor blades in multiple stages; and a cooling-side stator and a heating-side stator that hold the stator blades in multiple stages at predetermined intervals. An opening of a gap of a predetermined width configured to provide thermal insulation between the cooling-side stator and the heating-side stator is located at a position where the opening does not face outer circumference surfaces of the rotor blades in an axial direction of the rotating body.

1 . A vacuum pump comprising:
 a casing having an inlet port and an outlet port;   a rotor shaft rotationally supported inside the casing;   rotor blades in multiple stages, the rotor blades being rotatable together with the rotor shaft;   stator blades in multiple stages, the stator blades being fixed to the casing and located respectively between the rotor blades in multiple stages; and   a cooling-side stator and a heating-side stator that hold the stator blades in multiple stages at predetermined intervals,   wherein an opening of a gap of a predetermined width configured to provide thermal insulation between the cooling-side stator and the heating-side stator is located at a position where the opening does not face outer circumference surfaces of the rotor blades in an axial direction of the rotor shaft.   
     
     
         2 . The vacuum pump according to  claim 1 , wherein a shape of the gap includes a first gap section extending horizontally outward in a radial direction perpendicular to the axial direction and a second gap section extending further outward in the radial direction from an outer end of the first gap section and toward a downstream side in the axial direction. 
     
     
         3 . The vacuum pump according to  claim 1 , wherein the shape of the gap includes a third gap section extending toward a downstream side in the axial direction. 
     
     
         4 . The vacuum pump according to  claim 1 , wherein the shape of the gap includes a fourth gap section extending outward in a radial direction perpendicular to the axial direction and toward an upstream side in the axial direction. 
     
     
         5 . The vacuum pump according to  claim 1 , wherein the shape of the gap includes an overhang portion that is located above the opening and protrudes further inward of the casing than the opening.