Regenerative pump

Abstract

A light, cheap, and high-performance regenerative pump for pumping a methanol-water fuel of a fuel cell, which is adapted to the fuel. At least one of an impeller of the regenerative pump and an inner wall of the pump is made of polyphenylene sulfide or polyphenylene sulfide containing a filler. A thrust clearance formed between the pump chamber inner wall and an impeller peripheral face is set so as to be assured even in a state where the impeller swells.

What is claimed is:  
     
         1 . A regenerative pump, comprising: 
 an impeller; and    a pump chamber having therein the impeller rotatably mounted, wherein at least one of the impeller of the regenerative pump and an inner wall of the pump chamber is formed by using polyphenylene sulfide to pump one of water, methanol, and a mixture solution of water and methanol.    
     
     
         2 . The regenerative pump according to  claim 1 , wherein a thrust clearance formed between the pump chamber inner wall and an impeller peripheral face is set so as to be assured even in a state where the impeller swells.  
     
     
         3 . The regenerative pump according to  claim 1 , wherein polyphenylene sulfide contains a filler.  
     
     
         4 . The regenerative pump according to  claim 2 , wherein polyphenylene sulfide contains a filler.  
     
     
         5 . A regenerative pump, comprising: 
 a housing having a pump chamber; and    an impeller rotatably mounted in the housing to rotate within the pump chamber, wherein at least one of an inner surface of the pump chamber and the impeller is made of a hygroscopic resistant resin and a gap between a hub of the impeller and each inner side of the pump chamber adjacent the hub of the impeller is set to a predetermined distance to ensure a thrust clearance exists even when the impeller swells.    
     
     
         6 . The regenerative pump according to  claim 5 , wherein the regenerative pump pumps one of water, methanol, and a methanol-water mix.  
     
     
         7 . The regenerative pump according to  claim 5 , wherein the hygroscopic resistant resin is polyphenylene sulfide.  
     
     
         8 . The regenerative pump according to  claim 6 , wherein the hygroscopic resistant resin is polyphenylene sulfide.  
     
     
         9 . The regenerative pump, according to  claim 7 , wherein the polyphenylene sulfide contains a filler.  
     
     
         10 . The regenerative pump, according to  claim 8 , wherein the polyphenylene sulfide contains a filler.  
     
     
         11 . The regenerative pump according to  claim 5 , wherein a total thrust clearance between both sides of the hub of the impeller and the inner sides of the pump chamber adjacent the hub of the impeller is 0.07 mm which, when divided in half, gives a predetermined distance of 0.035 mm.