Centrifugal pump and a static seal thereof

Abstract

The present invention relates to a centrifugal pump and a static seal of the dynamic sealing thereof. The invention especially relates to modifying the attachment of said static seal and a seal cover acting as a counter ring thereof in such a way that, for example, when the static seal wears, the clearance thereof can be adjusted without a need to stop the pump. A characteristic feature of a centrifugal pump in accordance with the invention, comprising, among other things, a pump housing ( 72 ), a shaft ( 12 ), an impeller arranged on the shaft and a dynamic seal ( 30, 32 ) arranged in connection with the shaft ( 12 ), and a static seal arranged in connection with the shaft ( 12 ) behind the dynamic seal as seen from the impeller, said static seal comprising a flexible seal means ( 50 ) on the shaft ( 12 ) and a stationary counter ring thereof, is that a seal cover ( 62 ) including a stationary counter ring ( 60 ) is adjustable in the axial direction of the pump.

1 . A centrifugal pump, comprising a pump housing ( 72 ), a shaft ( 12 ), an impeller attached on the shaft, and a dynamic sealing ( 30 ,  32 ) arranged in connection with the shaft ( 12 ), and a static seal arranged in connection with the shaft ( 12 ) behind the dynamic sealing as seen from the impeller, said static seal comprising a flexible seal means ( 50 ) on the shaft ( 12 ) and a stationary counter ring thereof, characterized in that a seal cover ( 62 ) including a stationary counter ring ( 60 ) is adjustable in the axial direction of the pump.  
   
   
       2 . Centrifugal pump in accordance with  claim 1 , characterized in that the clearance of the static seal may be adjusted while the pump is running.  
   
   
       3 . Centrifugal pump in accordance with  claim 1 , characterized in that a seal cover ( 62 ) is attached to a pump housing ( 72 ) and/or to a cover of the housing by means of adjusting means ( 64 ,  66 ,  68 ).  
   
   
       4 . Centrifugal pump in accordance with  claim 1 , characterized in that said adjusting means comprise a flange ( 64 ) of the seal cover and the attachment bolts or headless screws ( 66 ) with nuts ( 68 ).  
   
   
       5 . Centrifugal pump in accordance with  claim 1 , characterized in that an extension of the seal cover ( 62 ) towards the pump bearing acts as shaft cover.  
   
   
       6 . Centrifugal pump in accordance with  claim 1 , characterized in means for collecting liquid leaking from the static seal to the seal cover ( 62 ) and for leading such further to a leakage collection system ( 70 ).  
   
   
       7 . Centrifugal pump in accordance with  claim 1 , characterized in that the flexible seal means ( 50 ) of the static seal is located on the pump shaft, and is formed of a cylindrical portion ( 52 ), an annular constricted portion ( 54 ), and a lip ( 56 ).  
   
   
       8 . Centrifugal pump in accordance with  claim 1 , characterized in that said seal means ( 50 ) prevents the liquid to be pumped from getting into contact with the pump shaft ( 12 ).  
   
   
       9 . A static seal to be used in connection with a dynamic sealing of a centrifugal pump, said static seal comprising a flexible seal means ( 50 ) and a stationary counter ring thereof, characterized in that the counter ring ( 60 ) is a part of the seal cover ( 62 ) together with a flange ( 64 ), by means of which flange the clearance of the static seal is adjusted.  
   
   
       10 . Static seal in accordance with  claim 9 , characterized in that the flexible seal means ( 50 ) of a static seal to be assembled on the shaft is formed at its one end of a substantially cylindrical portion ( 52 ), of an annular constricted portion ( 54 ) and, at its other end, of a radially outwards extending lip ( 56 ) of the seal means ( 50 ), one side of which forms an end surface ( 58 ) of the seal means ( 50 ) and operates together with the counter ring ( 60 ).  
   
   
       11 . Static seal in accordance with  claim 10 , characterized in that said end surface ( 58 ) is substantially radial.  
   
   
       12 . Static seal in accordance with  claim 9 , characterized in that the end surface ( 58 ) of the seal means ( 50 ) is inclined either completely or partially.  
   
   
       13 . Static seal in accordance with  claim 8 , characterized in that said radially outermost part of the lip ( 56 ) forms the tip of the lip, which is in contact with the counter ring ( 60 ) when the seal is in operation.  
   
   
       14 . Static seal in accordance with  claim 9 , characterized in that said tip of the lip ( 56 ) extends axially further than the rest of the lip.  
   
   
       15 . Static seal in accordance with  claim 9 , characterized in that the seal cover ( 62 ) is substantially cylindrical of its form, forming a shaft cover.  
   
   
       16 . Static seal in accordance with  claim 9 , characterized in that the seal cover is provided with means for guiding the leakage liquid to a leakage collection system.