Vacuum pump and spacer

Abstract

There are proposed a vacuum pump capable of suppressing a temperature increase of a stator blade by heat from a heating source without increasing the number of components, and a spacer used in such a vacuum pump. The present invention is a vacuum pump including a plurality of rotor blades which rotate together with rotating shafts, a plurality of stator blades which are disposed in multiple tiers between the rotor blades, and a plurality of spacers which are provided in multiple tiers inside casings and hold respectively the stator blades at predetermined positions, and, in the vacuum pump, at least one spacer of the plurality of spacers holding the stator blade has a concave surface in a contact surface which comes into contact with the stator blade.

1 . A vacuum pump comprising:
 a casing;   a rotating shaft which is rotatably supported inside the casing;   a plurality of rotor blades which are provided in multiple tiers on an outer periphery of the rotating shaft and rotate together with the rotating shaft;   a plurality of stator blades which are disposed in multiple tiers between the rotor blades; and   a plurality of spacers which are provided in multiple tiers inside the casing and hold respectively the stator blades at predetermined positions, wherein   at least one of the plurality of spacers holding the stator blade has a concave surface in a contact surface which comes into contact with the stator blade.   
     
     
         2 . The vacuum pump according to  claim 1 , wherein
 the concave surface is provided in the contact surface positioned on an outlet side.   
     
     
         3 . The vacuum pump according to  claim 1 , wherein
 the plurality of spacers include a spacer which is positioned closest to the outlet side has the concave surface.   
     
     
         4 . The vacuum pump according to  claim 1 , wherein
 the spacer having the concave surface is formed from a wrought material by cutting.   
     
     
         5 . The vacuum pump according to  claim 4 , wherein
 the wrought material is an aluminum alloy.   
     
     
         6 . A spacer used in a vacuum pump including:
 a casing;   a rotating shaft which is rotatably supported inside the casing;   a plurality of rotor blades which are provided in multiple tiers on an outer periphery of the rotating shaft and rotate together with the rotating shaft; and   a plurality of stator blades which are disposed in multiple tiers between the rotor blades,   the spacer being provided in multiple tiers inside the casing, and holding respectively the stator blades at predetermined positions, wherein   at least one of a plurality of the spacers holding the stator blade has a concave surface in a contact surface which comes into contact with the stator blade.