Electro-hydraulic pump (e-pump)

Abstract

A motor may comprise a stator and a rotor rotatable relative to the stator. A portion of the rotor may house a hydraulic pumping element of a hydraulic pump for effectuating movement of fluid from an inlet to an outlet thereby transforming the rotational power of the shaft into hydraulic power. Specifically, an electro-hydraulic pump may include a piston pump barrel assembly including a plurality of pistons arranged around a central axis for pumping hydraulic fluid and a cam for displacing the plurality of pistons when relative movement between the cam and the plurality of pistons occurs. A plurality of magnets may be fixedly attached to the outside of the piston pump barrel assembly, and electrical windings may radially surround the magnets and be configured to create a magnetic field when energized so as to cause the plurality of magnets and a portion of the piston pump barrel assembly to rotate relative to the windings, thereby actuating the plurality of pistons to pump hydraulic fluid.

What is claimed is: 
     
         1 . An electro-hydraulic pump comprising:
 a motor including:
 a stator; and 
 a rotor rotatable with respect to the stator and including a rotor body housing a hydraulic pumping element driven relative to the rotor body by rotation of the rotor for effectuating movement of fluid from an inlet to an outlet thereby transforming the rotational power of the rotor into hydraulic power. 
   
     
     
         2 . The electro-hydraulic pump of  claim 1 , wherein the stator concentrically surrounds the rotor. 
     
     
         3 . The electro-hydraulic pump of  claim 1 , wherein the motor is flooded with hydraulic fluid. 
     
     
         4 . The electro-hydraulic pump of  claim 1  wherein the hydraulic pumping element is an axial piston pump. 
     
     
         5 . The electro-hydraulic pump of  claim 1  wherein the hydraulic pumping element is contained within a motor housing. 
     
     
         6 . The electro-hydraulic pump of  claim 1  wherein the motor is a brushless DC motor. 
     
     
         7 . The electro-hydraulic pump of  claim 1  wherein the stator has electrical windings. 
     
     
         8 . The electro-hydraulic pump of  claim 1 , wherein the rotor includes permanent magnets. 
     
     
         9 . An electro-hydraulic pump comprising:
 a piston pump barrel assembly including:
 a plurality of pistons arranged and rotatable around a central axis for pumping hydraulic fluid, 
 a cam for axially displacing the plurality of pistons when relative rotational movement between the cam and the plurality of pistons occurs; 
   a plurality of magnets fixedly attached to the outside of the piston pump barrel assembly; and   electrical windings radially surrounding the magnets and configured to create a magnetic field when energized so as to cause the plurality of magnets and a portion of the piston pump barrel assembly to rotate relative to the windings, thereby actuating the plurality of pistons to pump hydraulic fluid.   
     
     
         10 . The electro-hydraulic pump of  claim 9 , wherein the cam is stationary with respect to the windings and the plurality of pistons is rotatable about the central axis. 
     
     
         11 . The electro-hydraulic pump of  claim 9  further comprising an outer housing, and wherein the electro-hydraulic pump is flooded with hydraulic fluid.