Vacuum pump with wear adjustment

Abstract

A vacuum pump having components that are subject to wear may be adjusted to compensate for the wear. In some instances, a vacuum pump may include a housing and an impeller disposed at least partially within the housing. A gap between the housing and the impeller may be adjustable to compensate for wear. In some cases, the housing may include a ring that may be moved to adjust a tolerance (or gap) between the ring and the impeller. In some instances, the ring may be rotated to adjust this gap. In other instances, the ring may be translated to adjust the tolerance.

1 . A liquid ring vacuum pump comprising:
 a base plate;   an eccentric ring disposed adjacent the base plate such that the eccentric ring may be rotated relative to the base plate;   an impeller disposed within the eccentric ring; and   a cover plate disposed over the eccentric ring, the cover plate secured to the base plate.   
   
   
       2 . The liquid ring vacuum pump of  claim 1 , wherein the cover plate spans the eccentric ring and extends beyond an outer diameter of the eccentric ring. 
   
   
       3 . The liquid ring vacuum pump of  claim 2 , wherein the cover plate comprises a plurality of bolt apertures, the base plate comprises a plurality of threaded apertures, and the cover plate is secured to the base plate via a plurality of bolts extending through the plurality of bolt apertures into the plurality of threaded apertures. 
   
   
       4 . The liquid ring vacuum pump of  claim 3 , wherein the plurality of bolts are disposed exterior to the eccentric ring. 
   
   
       5 . The liquid ring vacuum pump of  claim 1 , wherein at least one of the eccentric ring and the cover plate are sufficiently flexible to withstand water freezing within the liquid ring vacuum pump. 
   
   
       6 . The liquid ring vacuum pump of  claim 1 , wherein the eccentric ring comprises a polymeric material. 
   
   
       7 . The liquid ring vacuum pump of  claim 1 , wherein the cover plate comprises a polymeric material. 
   
   
       8 . The liquid ring vacuum pump of  claim 1 , wherein the eccentric ring has a wall thickness that varies from a minimum wall thickness to a maximum wall thickness. 
   
   
       9 . The liquid ring vacuum pump of  claim 1 , wherein the base plate is formed as part of a housing. 
   
   
       10 . The liquid ring vacuum pump of  claim 1 , further comprising a port plate disposed between the base plate and the impeller. 
   
   
       11 . A liquid ring vacuum pump comprising:
 a base plate;   an eccentric ring disposed adjacent to the base plate; and   an impeller disposed within the eccentric ring;   wherein the eccentric ring is rotatable relative to the impeller to define an adjustable tolerance therebetween.   
   
   
       12 . The liquid ring vacuum pump of  claim 11 , wherein the adjustable tolerance comprises a minimum distance between the eccentric ring and the impeller. 
   
   
       13 . The liquid ring vacuum pump of  claim 11 , wherein the eccentric ring has an outer annular surface defined by a first circle and an inner annular surface defined by a second circle, the second circle being offset from the first circle. 
   
   
       14 . The liquid ring vacuum pump of  claim 13 , wherein the base plate includes an annular groove, and the eccentric ring is disposed at least partially within the annular groove. 
   
   
       15 . The liquid ring vacuum pump of  claim 14 , wherein the annular groove is concentric with the first circle and sized to accommodate the outer annular surface of the eccentric ring. 
   
   
       16 . A method of compensating for wear within a liquid ring vacuum pump comprising a base plate, an eccentric ring disposed proximate the base plate, an impeller disposed within the eccentric ring and a cover plate disposed over the eccentric ring, the method comprising the steps of:
 loosening the cover plate;   rotating the eccentric ring; and   tightening the cover plate.   
   
   
       17 . The method of  claim 16 , wherein the step of rotating the eccentric ring provides a reduced tolerance between the eccentric ring and the impeller. 
   
   
       18 . The method of  claim 16 , further comprising a step of removing the cover plate prior to rotating the eccentric ring. 
   
   
       19 . The method of  claim 18 , further comprising a step of measuring a tolerance between the impeller and the eccentric ring after rotating the eccentric ring. 
   
   
       20 . The method of  claim 16 , wherein the eccentric ring comprises one or more setpoint markings, and rotating the eccentric ring comprises rotating the eccentric ring sufficiently to align one of the one or more setpoint markings with an alignment mark on the base plate.