Integrated motor and pump assembly

Abstract

A pump assembly that includes a crankshaft having main journals and crankpin journals, rods operatively coupled with the crankpin journals, reciprocating members operatively coupled with the rods, and an electric motor operable to rotate the crankshaft. The electric motor includes a stator and a rotor. The rotor is directly connected with the crankshaft and is operable to rotate the crankshaft to move the plurality of rods and reciprocating members to move a fluid.

What is claimed is: 
     
         1 . An apparatus, comprising:
 a pump assembly, comprising:
 a drive shaft; 
 a plurality of rods operatively coupled with the drive shaft; 
 a plurality of reciprocating members each operatively coupled with a corresponding one of the plurality of rods; and 
 an electric motor operable to rotate the drive shaft, wherein the electric motor comprises a rotor having a rotor shaft, wherein the rotor shaft is connected with the drive shaft, wherein the rotor shaft is operable to rotate the drive shaft and thus move the plurality of rods and reciprocating members, wherein the rotor shaft and the drive shaft rotate at the same speed, and wherein the plurality of reciprocating members are operable to move a fluid. 
   
     
     
         2 . The apparatus of  claim 1  wherein the rotor further comprises a plurality of permanent magnets. 
     
     
         3 . The apparatus of  claim 1  wherein the pump assembly does not comprise a transmission operatively connecting the rotor shaft and the drive shaft. 
     
     
         4 . The apparatus of  claim 1  wherein the rotor shaft and the drive shaft are integral portions of a single discrete member. 
     
     
         5 . The apparatus of  claim 1  wherein the pump assembly further comprises a swashplate connected with the drive shaft, and wherein each of the plurality of rods is operatively coupled with the swash plate. 
     
     
         6 . The apparatus of  claim 1  wherein the drive shaft comprises a crankshaft that includes a plurality of main journals connected with the rotor shaft. 
     
     
         7 . The apparatus of  claim 1  wherein:
 the drive shaft comprises a crankshaft; 
 the electric motor is one of a plurality of electric motors collectively operable to rotate the crankshaft; 
 each of the plurality of electric motors comprises a rotor having a rotor shaft and a plurality of magnets; 
 the rotor shaft of each of the plurality of electric motors is connected with the crankshaft; 
 the rotor shaft of each of the plurality of electric motors is operable to rotate the crankshaft and thus move a corresponding one of the plurality of rods; 
 the rotor shaft of each of the plurality of electric motors and the crankshaft rotate at the same speed; 
 the rotor shaft of at least one of the plurality of electric motors comprises an axial bore extending therethrough; 
 the crankshaft extends though the axial bore; and 
 at least one of the plurality of electric motors is disposed between two or more of the plurality of rods. 
 
     
     
         8 . The apparatus of  claim 1  wherein:
 the drive shaft comprises a crankshaft; 
 the electric motor is one of a plurality of electric motors collectively operable to rotate the crankshaft; 
 the crankshaft comprises a plurality of crankpin journals each operatively coupled with a corresponding one of the plurality of rods; 
 the crankshaft comprises a plurality main journals each connected with a rotor shaft of a corresponding one of the plurality of electric motors; and 
 at least one of the plurality of electric motors is disposed between two or more of the plurality of crankpin journals. 
 
     
     
         9 . The apparatus of  claim 1  wherein the rotor shaft comprises an axial bore extending longitudinally therethrough, and wherein the drive shaft extends through the axial bore. 
     
     
         10 . The apparatus of  claim 1  wherein:
 the electric motor is a first electric motor; 
 the rotor is a first rotor; 
 the rotor shaft is a first rotor shaft; 
 the plurality of magnets comprises a plurality of first magnets; 
 the pump assembly further comprises a second electric motor operable to rotate the drive shaft; 
 the second electric motor comprises a second rotor having a second rotor shaft and a plurality of second magnets; 
 the second rotor shaft is connected with the drive shaft; 
 the second rotor shaft is operable to rotate the drive shaft and thus move the plurality of rods; and 
 the second rotor shaft and the drive shaft rotate at the same speed. 
 
     
     
         11 . The apparatus of  claim 10  wherein:
 the first rotor shaft comprises a first axial bore extending longitudinally therethrough; 
 the second rotor shaft comprises a second axial bore extending therethrough; 
 the drive shaft is disposed within the first and second axial bores; and 
 at least one of the first and second electric motors is disposed between two or more of the plurality of rods. 
 
     
     
         12 . An apparatus, comprising:
 a pump assembly, comprising:
 a crankshaft comprising a plurality of main journals and a plurality of crankpin journals; 
 a plurality of rods each operatively coupled with a corresponding one of the plurality of crankpin journals; 
 a plurality of reciprocating members each operatively coupled with a corresponding one of the plurality of rods; and 
 an electric motor operable to rotate the crankshaft, wherein the electric motor comprises a stator and a rotor, wherein the rotor is directly connected with the crankshaft, and wherein the rotor is operable to rotate the crankshaft and thus move the plurality of rods, thereby causing the plurality of reciprocating members to move a fluid. 
   
     
     
         13 . The apparatus of  claim 12  wherein the rotor further comprises a plurality of permanent magnets. 
     
     
         14 . The apparatus of  claim 12  wherein the rotor further comprises a rotor shaft, and wherein the rotor shaft is connected with the crankshaft and at least one of the plurality of main journals. 
     
     
         15 . The apparatus of  claim 14  wherein the rotor shaft comprises an axial bore extending longitudinally therethrough, and wherein the crankshaft extends through the axial bore. 
     
     
         16 . A method, comprising:
 connecting a fluid source to a pump assembly comprising:
 a drive shaft; 
 a plurality of rods operatively coupled with the drive shaft; 
 a plurality of reciprocating members operatively coupled with the plurality of rods; and 
 an electric motor comprising a stator and a rotor that is directly connected with the drive shaft; and 
   operating the electric motor to rotate the rotor and the drive shaft at the same speed such that the rotating drive shaft moves the plurality of rods and reciprocating members to pump the fluid from the fluid source through the pump assembly.   
     
     
         17 . The method of  claim 16  wherein:
 the electric motor comprises an axial bore extending through the rotor; 
 the drive shaft extends through the axial bore; 
 the rotating drive shaft rotates within the axial bore; 
 the drive shaft comprises a crankshaft; 
 the crankshaft comprises a plurality of crankpin journals operatively coupled with the plurality of rods; 
 the crankshaft comprises a plurality of main journals connected with the rotor; 
 the electric motor comprises a plurality of openings extending laterally from the axial bore; and 
 operating the electric motor to rotate the rotor and the crankshaft moves the plurality of rods through the plurality of openings. 
 
     
     
         18 . The method of  claim 16  wherein:
 the drive shaft is a crankshaft; 
 the electric motor is a first electric motor; 
 the stator is a first stator; 
 the rotor is a first rotor; 
 the pump assembly further comprises a second electric motor comprising a second stator and a second rotor; 
 the first and second electric motors are separated by a space; 
 the second rotor is directly connected with the crankshaft; and 
 the method further comprises operating the second electric motor to rotate the second rotor and the crankshaft at the same speed, wherein the rotating crankshaft moves the plurality of rods through the space between the first and second electric motors. 
 
     
     
         19 . The method of  claim 18  further comprising electrically connecting the first and second electric motors to an electric power source. 
     
     
         20 . The method of  claim 18  further comprising:
 synchronizing the speed of the first and second electric motors; and 
 monitoring speed of the first and second electric motors.