Impeller for coolant pumps

Abstract

A cooling water pump for internal combustion engine includes a base and an outer cover forming a water input chamber, an impeller supported on a shaft within said chamber, fed shaft includes a bearing/seal unit mounted within the base and the shaft extended outwardly for connection to the engine. A one-piece, fully enclosed and double shrouded impeller is secured to the shaft. Impeller has a central hub with an outer peripheral concave surface, a bottom convex end wall, vanes are secured to the central portion of the concave wall in the bottom wall and project outwardly therefrom with an outer top shroud. The base has a recess within which the bearing/seal unit is mounted. The recess extends outwardly beyond the outer edge convex wall of the hub from a cooling chamber. The vanes direct a portion of the water flowing through the passageway into the recess for cooling purposes and then back into the radially outer portion of the passageway for discharge with the flowing water into the outlet passageway. The radially inner end of the shroud and outer convex wall overlap each other to form a controlled entrance into the outlet passageway to divert part of the flow into the recess.The invention pertains to a cooling water pump for an internal combustion engine. The pump has a base and a cover that form a water chamber. The chamber includes a one- piece, shrouded impeller secured to a drive shaft driven by the engine. The impeller has a central hub with vanes that project outwardly along with its integral shroud to form a flow passageway to a discharge opening. The base has a recess within which a bearing/seal unit is mounted. The recess extends outwardly beyond the hub to form a cooling passageway to the recess. A portion of the water flowing through the flow passageway is directed into the recess to cool the seal unit, and then back to the flow passageway for discharge. The shroud and hub can overlap to help control the flow to the recess.

1. A water pump impeller for a cooling water pump unit including a housing defining a water chamber having a water inlet and a water outlet and having an impeller shaft in a seal/bearing unit mounted within the housing and configured to receive the water pump impeller connected to said impeller shaft within said water chamber, the improvement wherein said water pump impeller comprises a hub configured and constructed to be secured to said drive shaft and located within said water chamber, said hub having an outer peripheral wall extending from an innermost end of the hub axially and radially to a substantially flat bottom wall with the outer end of the hub spaced substantially from said water outlet;
 a plurality of circumferentially spaced pump vanes secured in circumferentially spaced relation to the outer peripheral wall of said hub and extending outwardly of said hub into close spaced relation to said water outlet, each said pump vane extending radially outwardly from said bottom wall; and    a shroud secured to the upper and radially outer edges of said vane extending outwardly beyond said hub into close spaced relation with said water outlet with said adjacent vanes defining flow passageways to the outer passageway of the housing wall adjacent said bottom wall, said shroud having a radially inner end portion overlying a radially outer portion of said hub to form an entrance portion of said flow passageway.    
     
     
       2. The water pump impeller of  claim 1  wherein said hub and vanes and shroud are formed as a single molded unit. 
     
     
       3. The water pump impeller of  claim 1  wherein the housing includes a bottom wall with the seal/bearing unit mounted in said bottom wall, and wherein said hub has a bottom wall located in spaced relation to the bottom wall of said housing, said vanes including an axial portion extending radially below said bottom wall of said hub and with said axial portion extending radially inwardly beneath said hub bottom wall, and said housing bottom wall having a cavity surrounding said seal/bearing unit, and said vanes and said hub constructed and configured to establish a diversion of a portion of the water from the flow passageway into and through said cavity and back to said flow passageway to positively cool the bearing/seal unit. 
     
     
       4. A water pump impeller for a cooling water pump unit having a cooling chamber defined by a housing and having a drive shaft rotatably mounted to said housing and projecting into said chamber, said housing having water inlet to said chamber and an outlet passageway from said chamber, said water pump impeller comprising a hub configured and constructed to be secured to said shaft within said chamber, said hub having an outer peripheral wall extending from an innermost portion of the hub axially and radially to a substantially flat bottom wall, a plurality of circumferentially spaced pump vanes secured in circumferentially spaced relation to the outer peripheral wall of said hub and extending outwardly of said hub, said pump vanes extending radially outwardly from said bottom wall and including a vane portion beneath the hub, and a shroud secured to the upper edges of said vane in spaced relation to said shaft and extending outwardly from said hub with said adjacent vane defining flow passageways to the outer passageway of the housing, said hub and vanes being constructed and configured to direct a portion of the water in said flow passageways into the space between said bottom wall of the hub and the housing wall adjacent said bottom wall to direct water into engagement with the seal/bearing unit. 
     
     
       5. The water pump impeller of  claim 4  wherein said hub and shroud and vanes are formed as a single molded unit. 
     
     
       6. The water pump impeller of  claim 5  wherein said impeller is formed of a plastic material. 
     
     
       7. The water pump impeller of  claim 4  wherein said outer peripheral edge of said hub is a substantially convex wall and said bottom wall of the hub is a flat radial wall. 
     
     
       8. The water pump impeller of  claim 4  wherein said housing includes a cavity with said seal/bearing unit located therein, and wherein said cooling water flow beneath said hub circulates through said cavity and about said seal/bearing unit. 
     
     
       9. The water pump impeller of  claim 4  wherein said housing includes an encircling side wall for enclosing the outer radial portions of said impeller, said outlet passageway of said housing constructed and configured as a circumferential water passageway terminating in an outlet immediately adjacent to the peripheral portion of said impeller for movement of water from the housing into said circumferential water passageway of the housing. 
     
     
       10. The water pump impeller of  claim 4  wherein the radially outer wall of said hub has a radially inner relatively constant diameter portion connected by a concave radial planar portion to a bottom edge portion, said bottom edge portion having a reverse convex curvature terminating in a flat bottom wall of said hub, said construction promoting the flow of a portion of the water in the flow passageway into said spaced between said bottom wall of the hub and the adjacent housing wall. 
     
     
       11. The water pump impeller of  claim 4  wherein each of said vanes is correspondingly constructed and includes a curved radially inner portion connected to the hub and extending radially outwardly and axially to an inclined portion extending radially outwardly and downwardly to the other end of said vane, each of said vanes further including a integral lower portion extending downwardly beneath and inwardly of said hub with said lower portion further extending outwardly from the hub to the outlet passageway. 
     
     
       12. The water pump impeller of  claim 11  wherein said hub, said vanes and said shroud are formed as a single integral molded member. 
     
     
       13. In combination, a cooling housing configured and constructed for interconnection to an internal combustion engine having a water inlet and a water outlet for connection to the engine cooling system, said water outlet begin connected to a circumferential outlet passageway adjacent an outer wall of said housing, said housing having a cover having an open end and a base,
 said base having a base wall with a shaft opening, said base being secured to the open end of said cover to close said chamber, a shaft rotatably mounted within said shaft opening, said base wall and including an outer exposed drive shaft connection and an inner shaft portion, said base wall having an encircling cavity about said shaft opening, a bearing and seal unit mounted within said shaft opening and projecting inwardly of said base within said cavity,    an impeller secured to the end of said shaft within said housing, said impeller having a hub secured to said shaft, said hub having a substantially concave circumferential surface, a plurality of circumferentially spaced and like vanes secured to said hub and having a radially inner portion connected to said concave circumferential surface and extending radially outwardly and circumferentially therefrom, each of said vanes projecting axially downwardly beneath said bottom wall of said hub and having an inner portion terminating in close spaced relation to said cavity, said vanes terminating in spaced relation to said outlet passageway, a shroud connected to the top outer edges of said vanes and defining circumferentially spaced flow passageways from said chamber to said circumferential outlet passageway whereby rotation of said impeller draws water through said cover and discharges the same into said outlet passageway with a portion of the water flow being directed by said vanes and said hub about the outer edge of said hub and into and through said cavity and thereby cooling of said bearing and seal unit.    
     
     
       14. The combination of  claim 13  wherein the radially outer edge of said hub is a substantially convex wall terminating in the bottom wall of said hub, said bottom wall being a substantially planar radial wall, the base having a flat upper wall opposing said hub bottom wall, said cavity being formed in said base upper wall and including a radial portion immediately adjacent said bearing and seal unit and an inclined outwardly extended outer wall extending from said radial portion to said flat bottom wall of said base, said vanes projecting below said bottom wall of the hub and extending radially inwardly to a distance substantially corresponding to the location of said inclined wall. 
     
     
       15. The combination of  claim 13  wherein said impeller is formed as a single molded member including the hub, vanes and shroud. 
     
     
       16. A water pump impeller for a cooling water pump unit of an internal combustion engine, the cooling water pump unit having a cooling chamber defined by a housing and having a drive shaft rotatably mounted via a seal/bearing unit to said housing and projecting into the chamber, the housing having a water inlet to the chamber and an outer passage from the chamber, said water pump impeller comprising:
   a hub configured and constructed to be secured to the shaft within the chamber, said hub having an outer peripheral wall extending from an innermost portion of said hub axially and radially to a substantially flat bottom wall;        a plurality of circumferentially spaced pump vanes secured in circumferentially spaced relation to said outer peripheral wall of said hub and extending outwardly of said hub, said pump vanes extending radially outwardly from said hub and having upper edges;        a shroud secured to said upper edges of said vanes in spaced relation to the shaft and extending outwardly from said hub with said adjacent vanes defining flow passageways to the outer passage of the housing; and,        said hub, shroud and vanes being constructed and configured to direct a portion of the water in said flow passageways into a cavity between said bottom wall of the hub and the housing to direct water into engagement with the seal/bearing unit.     
     
     
       17. The water pump impeller of  claim 16  and wherein said hub, shroud and vanes are formed as a single molded unit. 
     
     
       18. The water pump impeller of  claim 16  and wherein said impeller is formed of a plastic material. 
     
     
       19. The water pump impeller of  claim 16  and wherein said outer peripheral wall of said hub is a substantially convex wall and said bottom wall of said hub is a flat radial wall. 
     
     
       20. The water pump impeller of  claim 16  and wherein the seal/bearing unit is located in said cavity, the seal/bearing unit having a seal, and wherein the cooling water flowing beneath said hub circulates through said cavity and about said seal. 
     
     
       21. The water pump impeller of  claim 16  and wherein the housing includes an encircling side wall for enclosing outer radial portions of said impeller, the housing further constructed and configured with a circumferential water passageway terminating in an outlet immediately adjacent to a peripheral portion of said impeller for movement of water from the housing into the outer passage of the housing. 
     
     
       22. The water pump impeller of  claim 16  and wherein a radially outer wall of said hub has a radially inner relatively constant diameter portion connected by a concave radial planar portion to a bottom edge portion, said bottom edge portion having a reverse convex curvature terminating in a flat bottom wall of said hub, said construction promoting the flow of a portion of the water in said flow passageways into said cavity. 
     
     
       23. The water pump impeller of  claim 16  and wherein each of said vanes is correspondingly constructed and includes a curved radially inner portion connected to said hub and extending radially outwardly and axially to an inclined portion extending radially outwardly and downwardly to an outer end of said vane, each of said vanes further including an integral lower portion extending downwardly beneath and inwardly of said hub with said lower portion further extending outwardly from said hub to the outer passage. 
     
     
       24. The water pump impeller of  claim 16  and wherein said hub and shroud overlap. 
     
     
       25. The water pump impeller of  claim 16  and wherein the housing has an adjacent wall adjacent said bottom wall of said hub, and said adjacent wall and cavity extend from the seal/bearing unit to beyond said outer peripheral wall of said hub. 
     
     
       26. The water pump impeller of  claim 25  and wherein said adjacent wall has an inclined wall portion that forms said cavity and slopes toward the seal/bearing unit. 
     
     
       27. The water pump impeller of  claim 16  and wherein said vanes have a portion beneath said hub. 
     
     
       28. A water pump impeller for a cooling water pump unit of an internal combustion engine, the cooling water pump unit having a chamber defined by a housing and having a drive shaft rotatably mounted to the housing via a seal/bearing unit and projecting into the chamber, the housing having a water inlet to the chamber and an outer passage from the chamber, said water pump impeller comprising:
   a hub configured and constructed to be secured to the shaft within the chamber, said hub having an outer peripheral wall extending from an innermost portion of said hub axially and radially to a substantially flat bottom wall, the housing having an adjacent wall adjacent said bottom wall of said hub, and said adjacent wall forming a cavity that extends from the seal/bearing unit radially outward to beyond said outer peripheral wall of said hub, said adjacent wall having a portion that forms said cavity proximal the seal/bearing unit;        a plurality of circumferentially spaced pump vanes secured in circumferentially spaced relation to said outer peripheral wall of said hub and extending outwardly of said hub, said vanes extending radially outwardly from said hub and having upper edges;        a shroud secured to said upper edges of said vanes in spaced relation to the shaft and extending outwardly from said hub with said adjacent vanes defining flow passageways to the outer passage of the housing; and,        wherein said hub, shroud and vanes are formed as a simple integral molded member, and said hub, shroud and vanes direct a portion of the water in said flow passageways into said cavity and into engagement with the seal/bearing unit.     
     
     
       29. The water pump impeller of  claim 28  and wherein said vanes have a portion beneath said hub. 
     
     
       30. The water pump impeller of  claim 28  and wherein said portion of said adjacent wall is an incline wall portion that slopes toward the seal/bearing unit, and wherein said hub, shroud, vanes and inclined wall portion direct a portion of the water in said flow passageways into said cavity and into engagement with the seal/bearing unit. 
     
     
       31. The water pump impeller of  claim 28  and wherein said hub has a radially outer portion and said shroud has a radially inner end portion, and said radially outer portion of said hub overlaps said radially inner end portion of said shroud. 
     
     
       32. The water pump impeller of  claim 28  and wherein the seal/bearing unit has a seal and said impeller directs said portion of water into engagement with said seal.