Wet rotor circulators

Abstract

Wet rotor circulators are provided, in which a fixed volume of a control fluid is sealed within the rotor chamber, and the rotor chamber is sealed against entry of the circulating system fluid.

1 . A circulator for circulating fluid within a hydronic heating or cooling system, comprising: 
 (a) a wet rotor circulator motor comprising:    a motor housing,    a stator disposed within the motor housing and sealed from the circulating fluid,    a rotor chamber disposed within the stator, the rotor chamber also being sealed from the circulating fluid so that the circulating fluid does not enter the rotor chamber,    a control fluid sealed within the rotor chamber,    a rotor disposed within the rotor chamber and in contact with the control fluid, and    an impeller affixed to one end of the rotor, the stator and rotor configured with respect to one another so that the rotor is caused to rotate when the stator is energized; and    (b) a pump casing fastened to the motor housing, the pump casing comprising:    an inlet end for accepting the circulating fluid flowing into the pump casing, the inlet end being configured for attachment to a pipe of the hydronic heating system,    a casing volute into which the impeller extends from the motor, the casing volute being in fluid communication with the inlet of the pump casing, and    an outlet end for discharging the circulating fluid flowing from the pump casing, the outlet end being configured for attachment to a pipe of the hydronic heating system.    
   
   
       2 . The circulator of  claim 1  wherein the rotor chamber is sealed from the circulating fluid by a pressure-equalizing seal.  
   
   
       3 . The circulator of  claim 2  wherein the pressure-equalizing seal comprises a diaphragm seal.  
   
   
       4 . The circulator of  claim 2  wherein the pressure-equalizing seal comprises a bellows seal or a dynamic piston seal.  
   
   
       5 . The circulator of  claim 1  or  2  wherein the rotor chamber is sealed from the circulating fluid by a dynamic seal selected from the group consisting of lip seals and v-ring seals.  
   
   
       6 . The circulator of  claim 5  wherein the dynamic seal is selected from the group consisting of spring biased single, double and triple lip seals.  
   
   
       7 . The circulator of  claim 1  or  2  wherein the rotor chamber is sealed from the circulating fluid by a mechanical seal comprising a rotating component and a stationary component.  
   
   
       8 . The circulator of  claim 7  wherein the rotating component is configured to be press-fit around a shaft portion of the rotor.  
   
   
       9 . The circulator of  claim 8  wherein the stationary component is configured to be press-fit into a receiving portion of the motor housing.  
   
   
       10 . The circulator of  claim 7  wherein the mechanical seal is configured to act as a thrust bearing, inhibiting axial movement of the rotor towards the impeller.  
   
   
       11 . The circulator of  claim 1  further comprising a rotor bushing/thrust washer assembly positioned and configured to support the rotor at an end of the rotor opposite the end to which the impeller is affixed.  
   
   
       12 . The circulator of  claim 11  wherein the rotor bushing comprises an engineered polymer.  
   
   
       13 . A wet rotor circulator motor comprising: 
 a motor housing,    a stator disposed within the motor housing and sealed from the circulating fluid,    a rotor chamber disposed within the stator, the rotor chamber also being sealed from the circulating fluid so that the circulating fluid does not enter the rotor chamber,    a control fluid sealed within the rotor chamber,    a rotor disposed within the rotor chamber and in contact with the control fluid, and    an impeller affixed to one end of the rotor, the stator and rotor configured with respect to one another so that the rotor is caused to rotate when the stator is energized.    
   
   
       14 . A circulator for circulating fluid within a hydronic heating or cooling system, comprising: 
 (a) a wet rotor circulator motor comprising:    a motor housing,    a stator disposed within the motor housing and sealed from the circulating fluid,    a rotor chamber disposed within the stator,    a rotor disposed within the rotor chamber and including a rotor shaft,    a dynamic seal positioned to seal against the rotor shaft on a first side of the rotor, and configured to inhibit axial movement of the rotor in a first direction,    a rotor bushing/thrust washer assembly positioned around the rotor shaft on a second side of the rotor and configured to inhibit axial movement of the rotor in a second direction, and    an impeller affixed to one end of the rotor shaft, the stator and rotor configured with respect to one another so that the rotor is caused to rotate when the stator is energized; and    (b) a pump casing fastened to the motor housing, the pump casing comprising:    an inlet end for accepting the circulating fluid flowing into the pump casing, the inlet end being configured for attachment to a pipe of the hydronic heating system,    a casing volute into which the impeller extends from the motor, the casing volute being in fluid communication with the inlet of the pump casing, and    an outlet end for discharging the circulating fluid flowing from the pump casing, the outlet end being configured for attachment to a pipe of the hydronic heating system.    
   
   
       15 . A circulator for circulating fluid within a hydronic heating or cooling system, comprising: 
 (a) a wet rotor circulator motor comprising:    a motor housing,    a stator disposed within the motor housing,    a rotor chamber disposed within the stator,    a rotor disposed within the rotor chamber, and    an impeller affixed to one end of the rotor, the stator and rotor configured with respect to one another so that the rotor is caused to rotate when the stator is energized; and    (b) a pump casing fastened to the motor housing, the pump casing comprising:    an inlet end for accepting circulating fluid flowing into the pump casing, the inlet end being configured for attachment to a pipe of the hydronic heating system,    a casing volute into which the impeller extends from the motor, the casing volute being in fluid communication with the inlet of the pump casing, and    an outlet end for discharging the circulating fluid flowing from the pump casing, the outlet end being configured for attachment to a pipe of the hydronic heating system;    wherein the motor housing and pump casing are configured so that the pump casing may be fastened to the motor housing by rotating the pump casing with respect to the motor housing.    
   
   
       16 . The circulator of  claim 15  wherein the motor housing and pump casing are configured so that they may be joined by a quarter turn rotation.  
   
   
       17 . The circulator of  claim 15  wherein the motor housing and pump casing include a pin and groove attachment system.