Centrifugal fluid pump

Abstract

A centrifugal fluid pump for circulating fluid through an engine's cooling system includes a body configured to be at least partially received within a bore in the engine, a shaft having an impeller rotatably connected to the body, the impeller being positioned to move fluid through the engine, and a shroud supported on the body and positioned between the duct and the impeller when the body is at least partially received within the bore. The shroud has an opening to permit the movement of fluid to the impeller and may be configured to engage an inner surface of the bore. The shroud remains stationary with respect to the bore as the shaft and the impeller rotate and the shroud and the bore cooperate to inhibit fluid from passing between the inner surface of the bore and the shroud to a position that is upstream of the shroud.

1 . A centrifugal fluid pump for circulating fluid through an engine, the engine having a bore to receive the pump and a duct to direct fluid radially into the pump, the engine further having a block with a discharge port formed therein to receive fluid discharged from the pump, the centrifugal fluid pump comprising:
 a body configured to be at least partially received within the bore;   a shaft rotatably connected to the body;   an impeller fixed to the shaft and rotatable therewith, the impeller being positioned to move fluid from the duct to the discharge port when the body is at least partially received within the bore; and   a shroud supported on the body and positioned between the duct and the impeller when the body is at least partially received within the bore, the shroud having an opening to permit movement of fluid from the duct to the impeller, the shroud being configured to engage an inner surface of the bore and the shroud remaining stationary with respect to the bore as the shaft and the impeller rotate,   whereby when the body is at least partially received within the bore, the shroud and the bore cooperate to inhibit the fluid that is received in the discharge port from flowing between the inner surface of the bore and the shroud to a position upstream of the shroud.   
   
   
       2 . The centrifugal fluid pump of  claim 1  further comprising a seal arrangement disposed along an outer surface of the shroud to form a seal between the outer surface of the shroud and the inner surface of the bore when the body is at least partially received within the bore to further inhibit the fluid that is received in the discharge port from flowing between the inner surface of the bore and the outer surface of the shroud to a position upstream of the shroud. 
   
   
       3 . The centrifugal fluid pump of  claim 2  wherein the seal arrangement includes an o-ring seal. 
   
   
       4 . The centrifugal fluid pump of  claim 2  wherein the outer surface of the shroud defines a groove to receive the seal arrangement. 
   
   
       5 . The centrifugal fluid pump of  claim 1  further comprising a wall defining a fluid receiving chamber, the wall being connected to an upstream portion of the shroud and having an inlet opening positioned to align with the duct when the body is at least partially received within the bore, the inlet opening permitting the fluid to flow radially into the fluid receiving chamber from the duct. 
   
   
       6 . The centrifugal fluid pump of  claim 5  further comprising a seal arrangement disposed along an outer surface of the wall, the seal arrangement forming a seal between the inner surface of the bore and the outer surface of the wall when the body is at least partially received within the bore to inhibit the fluid that is received within the discharge port from flowing between the inner surface of the bore and the outer surface of the wall to the inlet opening. 
   
   
       7 . The centrifugal fluid pump of  claim 6  wherein the seal arrangement includes an o-ring seal. 
   
   
       8 . The centrifugal fluid pump of  claim 6  wherein the outer surface of the wall defines a groove to receive the seal arrangement. 
   
   
       9 . The centrifugal fluid pump of  claim 1  further comprising:
 a seal arrangement disposed along an outer surface of the shroud to form a seal between the outer surface of the shroud and the inner surface of the bore when the body is at least partially received within the bore; and   a wall defining a fluid receiving chamber, the wall being connected to an upstream portion of the shroud, the wall defining an inlet opening positioned to align with the duct when the body is at least partially received within the bore, the inlet opening permitting fluid to flow radially into the fluid receiving chamber from the duct,   the seal arrangement inhibiting the fluid that is received within the discharge port from flowing between the inner surface of the bore and the shroud to the inlet opening.   
   
   
       10 . The centrifugal fluid pump of  claim 1  wherein a portion of the impeller is disposed in sufficiently close association with an outer surface of the shroud to inhibit fluid from flowing between the impeller and the outer surface of the shroud as the impeller rotates. 
   
   
       11 . A centrifugal fluid pump for circulating fluid through an engine, the engine having a bore to receive the pump and a fluid path to facilitate circulation of fluid through the engine, the engine further having a duct connected to the fluid path to direct fluid radially into the pump, the engine further having a block with a discharge port formed therein to receive fluid discharged from the pump, the discharge port being connected to the fluid path, the centrifugal fluid pump comprising:
 a housing configured to be at least partially received within the bore, the housing having a wall defining a fluid receiving chamber, the wall further defining an inlet to permit the radial flow of fluid into the fluid receiving chamber, the inlet aligning with the duct when the housing is at least partially received within the bore, the housing further having a shroud contiguous with the wall and disposed substantially transversely thereto, an inner surface of the shroud defining a portion of the fluid receiving chamber, the shroud having an outlet to permit the flow of fluid out of the chamber; and   an impeller assembly supported on the housing and rotatably connected thereto, the impeller assembly including a bearing connected to the housing, a shaft rotatably supported on the bearing and an impeller connected to the shaft, the impeller being disposed substantially adjacent to an outer surface of the shroud proximate to the outlet, the impeller being configured to rotate with respect to the shroud and to draw fluid out of the outlet as the impeller rotates, the impeller further being disposed proximate to the discharge port when the housing is at least partially received within the bore, the impeller being configured to move fluid into the discharge port as the impeller rotates,   the shroud remaining stationary with respect to the bore as the impeller rotates, and a periphery of the shroud being configured to engage an inner surface of the bore such that the periphery of the shroud and the inner surface of the bore cooperate to inhibit fluid from flowing upstream from the discharge port into the fluid receiving chamber.   
   
   
       12 . The centrifugal fluid pump of  claim 11  further comprising a seal arrangement disposed along the periphery of the shroud to form a seal between the periphery of the shroud and the inner surface of the bore when the housing is at least partially received within the bore to further inhibit the fluid that is received in the discharge port from flowing between the inner surface of the bore and the periphery of the shroud to a position upstream of the shroud. 
   
   
       13 . The centrifugal fluid pump of  claim 12  wherein the periphery of the shroud defines a groove to receive the seal arrangement. 
   
   
       14 . The centrifugal fluid pump of  claim 12  wherein the seal arrangement includes an o-ring seal. 
   
   
       15 . The centrifugal fluid pump of  claim 14  wherein the periphery of the shroud defines a groove to receive the o-ring. 
   
   
       16 . The centrifugal fluid pump of  claim 11  further comprising a seal arrangement disposed along an outer surface of the wall to form a seal between the outer surface of the wall and the inner surface of the bore when the housing is at least partially received within the bore to further inhibit the fluid that is received in the discharge port from flowing between the inner surface of the bore and the outer surface of the wall to the inlet. 
   
   
       17 . The centrifugal fluid pump of  claim 16  wherein the outer surface of the wall defines a groove to receive the seal arrangement. 
   
   
       18 . The centrifugal fluid pump of  claim 16  wherein the seal arrangement includes an o-ring seal. 
   
   
       19 . The centrifugal fluid pump of  claim 18  wherein the outer surface of the wall defines a groove to receive the o-ring seal. 
   
   
       20 . The centrifugal fluid pump of  claim 11  wherein a portion of the impeller is disposed in sufficiently close association with the outer surface of the shroud to inhibit fluid from flowing between the impeller and the outer surface of the shroud as the impeller rotates.