Vacuum pump

Abstract

A vacuum pump includes shaft, two spaced from each other, dynamic gas bearings for supporting the shaft for rotation, and a pumping system arranged on the shaft between the two gas bearings and having two pumping sections which are so formed that compressed gas from each section is delivered in a direction of a gas bearing adjacent to this pumping section.

1 . A vacuum pump, comprising a shaft; spaced from each other, first and second dynamic gas bearings for supporting the shaft for rotation; and
 a pumping system arranged on the shaft between the first and second gas bearings and having two pumping sections which are so formed that a compressed gas from each of the two pumping sections is delivered in a direction of a gas bearing adjacent to a respective pumping section.   
   
   
       2 . A vacuum pump according to  claim 1 , wherein each of the pumping sections and the gas bearing adjacent thereto are so arranged that at least a portion of an operational gas of the gas bearing and gas expelled from the respective pumping section are combined at a point and flow together to a pump outlet. 
   
   
       3 . A vacuum pump according to  claim 1 , wherein at least one of the two pumping sections includes a Holweck pumping stage 
   
   
       4 . A vacuum pump according to  claim 3 , wherein both rotor and stator of the Holweck stage each has channels extending in opposite directions. 
   
   
       5 . A vacuum pump according to  claim 1 , further comprising a further pumping system. 
   
   
       6 . A vacuum pump according to  claim 5 , wherein the further pumping system includes a hub connected with one end of the shaft, and a cylinder connected with the hub. 
   
   
       7 . A vacuum pump according to  claim 1 , further comprising a back-up bearing provided at one end of the shaft. 
   
   
       8 . A vacuum pump according to  claim 7 , wherein the back-up bearing is formed as a slide bearing. 
   
   
       9 . A vacuum pump according to  claim 1 , wherein a shaft material substantially consists of silicon carbide. 
   
   
       10 . A vacuum pump according to  claim 1 , further comprising a shaft driving motor having stator and rotor thereof so formed that an axial centering and simultaneously a rapid rotation of the shaft are provided for.