Pump with integral motor and impeller

Abstract

An integral motor and pump includes a casing having an inlet and an outlet, and a motor mounted within the casing. The motor includes a rotor member and a stator member. A tubular shaft circumscribing a central axis is received and fixed within the rotor. The tubular shaft is formed from a pair of axially overlapping tubular end portions and has an inner peripheral wall. An impeller is longitudinally spaced and press-fit within the inner peripheral wall of the shaft. The impeller includes a central, axially-extending body and a series of radially projecting blades, with each blade extending radially outward from the central body to the inner peripheral wall. When the motor is energized, the rotor turns, which in turn causes the impeller to rotate and draw fuel through the pump. When the motor is off, a flow path is maintained through the pump between the blades of the impeller.

What is claimed is:  
     
         1 . A fuel pump, comprising: 
 a casing having an inlet and an outlet, a motor mounted within said casing and including a rotor member and a stator member, a tubular shaft circumscribing a central axis received within the rotor and fixed to and rotatable therewith, said tubular shaft defining an inner peripheral wall therein, an impeller axially supported and press-fit within said inner peripheral wall of the shaft, said impeller including a central, axially-extending body and a series of radially projecting blades, each blade extending radially outward from said central body to said inner peripheral wall, and electrical connection means for energizing said motor to cause rotor rotation and in turn to cause impeller rotation.    
     
     
         2 . The fuel pump as in  claim 1 , and further including a vaned diffuser supported in the pump on a downstream side of the impeller.  
     
     
         3 . The fuel pump as in  claim 1 , wherein the shaft includes radially-inward projecting first and second shoulders forming axial stops for each end of the impeller, the stops axially locating the impeller within the tubular shaft.  
     
     
         4 . The fuel pump as in  claim 1 , wherein the tubular shaft includes a pair of spaced apart annular flange members, projecting radially outward from the shaft, and the rotor member is located between said annular flange members.  
     
     
         5 . The fuel pump as in  claim 4 , and further including a pair of bearing members radially outwardly supporting said tubular shaft in said casing, said bearing members each located on an axial opposite side of said flange members from the rotor member, said flange members each constituting an axial support for the bearing members.  
     
     
         6 . The fuel pump as in  claim 5 , wherein a bearing sleeve fixed to the casing supports each bearing member on i) a radially outer side; and ii) an axial end.  
     
     
         7 . The fuel pump as in  claim 6 , wherein each bearing member is fixed against rotation relative to the bearing sleeve by a key member.  
     
     
         8 . The fuel pump as in  claim 1 , wherein the shaft comprises an inlet end portion and an outlet end portion, each portion being concentrically aligned and having an axially overlapping section, said portions being fixed together along the overlapping section.  
     
     
         9 . The fuel pump as in  claim 8 , wherein the central shaft includes a pair of spaced apart, annular flange members, projecting radially outward from the shaft, and each portion carries one of the flange members, and the rotor member is located between said annular flange members.  
     
     
         10 . The fuel pump as in  claim 8 , wherein the outlet end portion includes a first radially-inward projecting shoulder forming a first axial stop for one end of the impeller, and the inlet end portion includes a second radially-inward projecting shoulder forming a second axial stop for another end of the impeller, the first and second stops axially locating the impeller within the tubular shaft.  
     
     
         11 . The fuel pump as in  claim 1 , wherein the shaft comprises an inlet end portion and an outlet end portion, each portion being concentrically aligned and having an axially overlapping section, said portions being fixed together along the overlapping section; and wherein the central shaft includes a pair of spaced apart, annular flange members, projecting radially outward from the shaft, and each portion carries one of the flange members; and the rotor member is located between said annular flange members; and further including a pair of bearing members radially outwardly supporting said tubular shaft in said casing, said bearing members each located on an axial opposite side of said flange members from the rotor member, said flange members each constituting an axial support for the bearing members; and a bearing sleeve fixed to the casing supports each bearing member on i) a radially outer side; and ii) an axial end; and the outlet end portion includes a first radially-inward projecting shoulder forming a first axial stop for one end of the impeller, and the inlet end portion includes a second radially-inward projecting shoulder forming a second axial stop for another end of the impeller, the first and second stops axially locating the impeller within the tubular shaft.