Stator disc for a turbomolecular pump

Abstract

A stator disc for a turbomolecular pump has an inner ring ( 3 ), an outer ring ( 4 ), and a plurality of vanes ( 2 ) formed of a stator disc plane, extending between the inner and outer rings ( 3, 4 ), and having, in connection regions of the vanes with the inner and outer rings, respective radial webs ( 5 ) a circumferential width (S) of which is smaller than a vane width (T).

1 . A stator disc for a turbomolecular pump, comprising an inner ring ( 3 ); an outer ring ( 4 ); and a plurality of vanes ( 2 ) formed of a stator disc plane, extending between the inner and outer rings ( 3 ,  4 ), and having, in connection regions of the vanes with the inner and outer rings, respective radial webs ( 5 ) a circumferential width (S) of which is smaller than a vane width (T).  
   
   
       2 . A stator disc according to  claim 1 , wherein the radial web ( 5 ) is arranged at a half distance between opposite edges ( 20 ,  21 ) of a respective vane.  
   
   
       3 . A stator disc according to  claim 1 , wherein the circumferential width (S) of a web ( 5 ) varies from about one/tenth to about one/second of the vane depth (T).  
   
   
       4 . A stator disc according to  claim 1 , wherein the stator disc is formed of at least two identical disc sections.  
   
   
       5 . A turbomolecular pump, comprising a housing including a flange for connecting the pump with a pump-out recipient and having a suction region, and an outlet; a rotor shaft arranged in the housing and carrying a plurality of rotor discs provided with vanes; a drive for driving the rotor shaft; and a plurality of stator discs fixedly secured in the housing and arranged between the rotor discs, at least one of the stator discs having a plurality of vanes formed of a stator disc plane, extending between the inner and outer rings ( 3 ,  4 ), and having, in connection regions of the vanes with the inner and outer rings, respective radial webs ( 5 ) a circumferential width (S) of which is smaller than a vane width (T).  
   
   
       6 . A method of forming a stator disc for a turbomolecular pump, comprising the steps of producing semi-circular discs with substantially radial slots by one of stamping and laser cutting; forming circumferential slots at opposite ends of the radial slots; and thereafter, curving out material between the radial slots so that it is squeezed out of planes of the discs in such a way that vanes with a web between a respective vane and at least one of the outer and inner disc edges are formed.  
   
   
       7 . A method according to  claim 6 , wherein all of the vanes are formed at once.