Molecular drag pumping mechanism

Abstract

A vacuum pump comprises a drive shaft and a Siegbahn pumping mechanism. The Siegbahn pumping mechanism comprises a rotor element located on the drive shaft and an annular stator element located about the drive shaft and proximate the rotor element, the stator element comprising a plurality of walls extending towards the rotor element and defining a plurality of spiral channels. The stator element comprises a plurality of sections, with means such as a resilient member being located about the sections to urge the sections together, and thereby inhibit gas leakage between the sections of the stator element. The resilient member can also form a seal between the stator sections and a casing located about the pumping mechanism.

1 . A pumping mechanism comprising a rotor element and a stator element located proximate the rotor element, one of the rotor element and the stator element comprising a plurality of walls extending towards the other one of the rotor element and the stator element and defining a plurality of spiral channels, the stator element comprising a plurality of sections and means for bringing the sections into contact. 
   
   
       2 . The pumping mechanism according to  claim 1  wherein the means for bringing the sections into contact comprises urging the sections into contact. 
   
   
       3 . The pumping mechanism according to  claim 1  wherein the means for bringing the sections into contact extends about the sections and forms a seal with a casing surrounding the rotor and stator elements. 
   
   
       4 . The pumping mechanism according to  claim 1  wherein the means for bringing the sections into contact comprises a resilient member extending about the sections. 
   
   
       5 . The pumping mechanism according to  claim 4  wherein the resilient member comprises an O-ring sealing element. 
   
   
       6 . (canceled) 
   
   
       7 . A vacuum pump comprising:
 a drive shaft;   a rotor element located on the drive shaft and an annular stator element located about the drive shaft and proximate the rotor element, one of the rotor element and the stator element comprising a plurality of walls extending towards the other of the rotor element and the stator element and defining a plurality of spiral channels, the stator element comprising a plurality of sections and means for bringing the sections into contact.   
   
   
       8 . The vacuum pump according to  claim 7  wherein the means for bringing the sections together comprises urging the sections towards the drive shaft. 
   
   
       9 . The vacuum pump according to  claim 7  wherein the means for bringing the sections into contact extends about the sections and forms a seal with a casing surrounding the rotor and stator elements. 
   
   
       10 . The vacuum pump according to  claim 7  wherein the means for bringing the sections into contact comprises a resilient member extending about the sections. 
   
   
       11 . The vacuum pump according to  claim 10  wherein the resilient member comprises a resilient, O-ring sealing element. 
   
   
       12 . The vacuum pump according to  claim 7  further comprising rotor elements located on a drive shaft and a annular stator elements located between the rotor elements, each of the stator elements comprising means for bringing the sections of that stator element into contact. 
   
   
       13 . The vacuum pump according to  claim 7  further comprising a turbomolecular pumping stage. 
   
   
       14 . (canceled) 
   
   
       15 . (canceled)