Turbomolecular vacuum pump with rows of rotor blades and rows of stator blades

Abstract

The invention relates to a turbomolecular vacuum pump comprising rows of rotor blades ( 3 ) and rows of stator blades ( 4 ) that alternately engage with one another at varying angles of attack (α). The aim of the invention is to improve the properties of such a pump. To this end, at least a part of the blades ( 1 or 2 ) of the rows of blades ( 3 or 4 ) that are mounted on the pressure side thickens towards the rim facing the pressure side.

1 . Turbomolecular vacuum pump comprising rows of rotor blades ( 3 ) and rows of stator blades ( 4 ) that alternately engage with one another at varying angles of attack (α), wherein at least a part of the blades ( 1  or  2 ) of the rows of blades ( 3  or  4 ) that are mounted on the pressure side thickens towards the rim facing the pressure side.  
     
     
         2 . Pump according to  claim 1 , wherein rim areas (11), (12) forming the pressure side rim of the thickened blades ( 1 ,  2 ) in each instance are located in a plane perpendicular with respect to the rotor axis ( 9 ).  
     
     
         3 . Pump according to  claim 1  or  2 , wherein the thickenings ( 10 ) of the thickened blades in the cross section through the blades ( 1 ,  2 ) are designed conically increasing in the direction of the pressure side.  
     
     
         4 . Pump according to  claim 3 , wherein the thickenings ( 10 ) increasing in the direction of the pressure side, commence at the pressure side half of the width of the blades ( 1 ,  2 ).  
     
     
         5 . Pump according to  claim 3  or  4 , wherein the thickenings ( 10 ) are provided on both sides or only on one side of the blades ( 1 ,  2 ).  
     
     
         6 . Pump according to  claim 5 , wherein the thickening ( 10 ) commences at a point of change ( 14 ) and where the angle (β) formed by the pressure side section ( 1 ″,  2 ″) of the boundary lines ( 1 ′,  1 ,″;  2 ′,  2 ″) of the blades ( 1 ,  2 ) with a connecting line ( 15 ) which forms the point of change ( 14 ) with the bottom rim of the in each instance opposing blade, is greater than 90°.  
     
     
         7 . Pump according to one of the above claims, wherein it is equipped with a filling stage ( 21 ) implemented by way of a radial stage.  
     
     
         8 . Pump according to  claim 7 , wherein the radial stage comprises ridges ( 23 ) extending towards the outside, the width of which decreases towards the outside.