Centrifugal pump with reinforced plastic impeller wheel

Abstract

A centrifugal pump has a housing forming a chamber having intake and output ports and a plastic lining in the chamber An impeller wheel in the chamber is formed by a hub rotatable about an axis, a rear disk projecting radially from the hub, a front disk projecting radially from the hub and offset axially from the rear disk, and radial vanes extending axially between the disks. The hub, disks, and vanes are formed of a high-strength material such as metal and carries a coating on outer surfaces of the hub, disks, and vanes of a plastic of lower strength than the material.

We claim: 
     
         1 . A centrifugal pump comprising:
 a housing forming a chamber having intake and output ports;   a plastic lining in the chamber; and   an impeller wheel in the chamber and formed by
 a hub rotatable about an axis, 
 a rear disk projecting radially from the hub, 
 a front disk projecting radially from the hub and offset axially from the rear disk; 
 radial vanes extending axially between the disks, the hub, disks, and vanes being formed of a high-strength material; and 
 a coating on outer surfaces of the hub, disks, and vanes of a plastic of lower strength than the material. 
   
     
     
         2 . The centrifugal pump defined in  claim 1 , wherein the front disk is cohesively or positively connected to the rear disk by the vanes. 
     
     
         3 . The centrifugal pump defined in  claim 2 , wherein the hub, disks, and vanes are integral. 
     
     
         4 . The centrifugal pump defined in  claim 2 , wherein the hub, disks, and vanes are unitary. 
     
     
         5 . The centrifugal pump defined in  claim 3 , wherein the hub, disks, and vanes are unitarily formed of cast metal. 
     
     
         6 . The centrifugal pump defined in  claim 1 , wherein the plastic coating on the hub, disks, and vanes, is of uniform thickness. 
     
     
         7 . The centrifugal pump defined in  claim 1  wherein the hub, disks, and vanes have surface formations interfitting with the plastic coating. 
     
     
         8 . The centrifugal pump defined in  claim 7  wherein the formations are grooves or holes. 
     
     
         9 . The centrifugal pump defined in  claim 1 , wherein the hub is configured to be rotated by a drive shaft. 
     
     
         10 . The centrifugal pump defined in  claim 1 , wherein the lining and the coating are of the same plastic.