Feed Screw For Eccentric Screw Pump

Abstract

The inventions relates to a feed screw for eccentric screw pumps which, to avoid bridge formation of the medium and optimisation of the drive power, has a screw, which in the axial region, has perforations and webs.

1 . An eccentric screw pump with an eccentrically rotating rotor which rotates in a stator provided with an additional screw start, wherein the rotor is connected with a drive via a coupling shaft and the coupling shaft is surrounded by a feed screw, characterized in that the feed screw has a screw which, per pitch, has at least two perforations and that the webs formed between these perforations are connected with the coupling shaft.  
   
   
       2 . The eccentric screw pump according to  claim 1 , characterized in that at least four perforations are present per screw pitch.  
   
   
       3 . The eccentric screw pump according to  claim 1 , characterized in that the coupling shaft has a screw pipe on which strip-shaped pipe segments are located at one end parallel to the longitudinal axis of the feed screw which are connected with the screw.  
   
   
       4 . The eccentric screw pump according to  claim 3 , characterized in that the number of pipe segments corresponds to the number of perforations.  
   
   
       5 . The eccentric screw pump according to  claim 1 , characterized in that the height of the perforations corresponds to between 30% and 70% of the height of the screw.  
   
   
       6 . The eccentric screw pump according to  claim 5 , characterized in that the height of the perforations corresponds to between 20% to 60% of the height of the screw.  
   
   
       7 . The eccentric screw pump according to  claim 3 , characterized in that the pipe segments in the operational state cover the joint element/s.  
   
   
       8 . The eccentric screw pump according to  claim 1 , characterized in that the width of the perforations corresponds to the width of the webs which are connected with the coupling rod.  
   
   
       9 . The eccentric screw pump according to  claim 1 , characterized in that the width of the perforations is greater than the width of the webs.  
   
   
       10 . The eccentric screw pump according to  claim 1 , characterized in that the width of the webs is greater than the width of the perforations.  
   
   
       11 . The eccentric screw pump according to  claim 1 , characterized in that the webs have an inclination opposite to the course of the screw.  
   
   
       12 . The eccentric screw pump according to  claim 1 , characterized in that the webs are offset to one another by 30° to 120°.  
   
   
       13 . The eccentric screw pump according to claims  7 , characterized in that the length of the pipe segments is adapted to the course of the screw.  
   
   
       14 . The eccentric screw pump according to  claim 1 , characterized in that the screw consists of several parts.  
   
   
       15 . The eccentric screw pump according to  claim 2 , characterized in that the coupling shaft has a screw pipe on which strip-shaped pipe segments are located at one end parallel to the longitudinal axis of the feed screw which are connected with the screw.  
   
   
       16 . The eccentric screw pump according to  claim 2 , characterized in that the height of the perforations corresponds to between 30% and 70% of the height of the screw.  
   
   
       17 . The eccentric screw pump according to  claim 4 , characterized in that the height of the perforations corresponds to between 30% and 70% of the height of the screw.  
   
   
       18 . The eccentric screw pump according to  claim 4 , characterized in that the pipe segments in the operational state cover the joint element/s.