Submersible motor-driven pump with an anti-frost device

Abstract

A submersible motor-driven pump includes a housing having an intake connection and a discharge connection; an impeller mounted in the housing between the intake connection and the discharge connection; and a shaft on which the impeller is mounted, the shaft being supported for rotation in the housing. The shaft extends concentrically into a cylindrical can mounted in the housing form a free space between the shaft and the can. Anti-freeze apparatus is installed in the housing for protecting the shaft.

1 - 5 . (canceled)  
   
   
       6 . A submersible motor-driven pump, comprising: 
 a housing having an intake connection and a discharge connection;    an impeller mounted in the housing between the intake connection and the discharge connection;    a shaft on which the impeller is mounted, the shaft being supported for rotation in the housing;    a cylindrical can mounted in the housing, said shaft extending concentrically into the can to form a free space between the shaft and the can; and    anti-freeze apparatus installed in the housing for protecting the shaft.    
   
   
       7 . The submersible motor driven pump of  claim 6  further comprising a ceramic bearing supporting the shaft, the anti-freeze apparatus comprising: 
 an elastomeric bushing supporting the ceramic bearing in an entrance of the can; and    a water displacer arranged in the free space.    
   
   
       8 . The submersible pump of  claim 6  wherein the anti-freeze apparatus comprises an elastomeric mount which supports the shaft in the impeller.  
   
   
       9 . The submersible pump of  claim 6  wherein the anti-freeze apparatus further comprises an elastomeric diaphragm mounted at a low point in the housing, the diaphragm being expandible when subjected to ice pressure.  
   
   
       10 . The submersible pump of  claim 6  wherein the shaft is a ceramic shaft.