Electric drive pump for well stimulation

Abstract

An electric drive pump system includes a power end and a detachable transmission assembly. The transmission assembly is mounted to the power end and is configured to provide rotational power to the power end through a plurality of electric motors. The plurality of electric motors use a gearbox to drive an output spline that engages the power end. A control module is used to regulate the performance characteristics of the plurality of electric motors. A temperature regulation assembly is configured to regulate the temperature of the transmission assembly and the power end.

What is claimed is: 
     
         1 . An electric drive hydraulic fracturing pump system, comprising:
 a hydraulic fracturing pump having a power end;   a plurality of electric motors, each electric motor having a motor output shaft with a spur gear mounted thereon; and   a gearbox in communication with the plurality of electric motors, the gearbox including a bull gear engaged by each of the spur gears of the plurality of electric motors,   and a planetary gear system coupled to the bull gear, the gears for transferring rotational energy from the electric motors to the power end.   
     
     
         2 . The system of  claim 1 , further comprising:
 a control module configured to regulate performance of the plurality of electric motors.   
     
     
         3 . The system of  claim 2 , wherein the control module is configured to individually regulate power output and runtime of each of the plurality of electric motors. 
     
     
         4 . The system of  claim 1 , wherein the plurality of electric motors are configured to operate simultaneously. 
     
     
         5 . The system of  claim 1 , wherein the plurality of electric motors are configured to operate independently from one another. 
     
     
         6 . The system of  claim 1 , wherein the plurality of electric motors can operate at different output power levels. 
     
     
         7 . The system of  claim 1 , further comprising:
 a circulation fan to pass air over the plurality of electric motors.   
     
     
         8 . An electric drive hydraulic fracturing pump system, comprising:
 a hydraulic fracturing pump having a power end with a pump crankshaft extending along a crankshaft axis;   a transmission assembly coupled to the power end pump crankshaft, the transmission assembly having:
 a plurality of electric motors radially spaced apart from one another about the crankshaft axis; and 
 a gearbox coupling the plurality of electric motors to the pump crankshaft, the gearbox including a plurality of gears for transferring rotational energy from the electric motors to the power end; and 
   a control module configured to regulate performance of the plurality of electric motors.   
     
     
         9 . The system of  claim 8 , further comprising:
 a temperature regulation assembly in communication with the control module for monitoring and regulating the temperature of the power end.   
     
     
         10 . The system of  claim 9 , wherein the temperature regulation assembly is configured to heat at least one of the power end and the transmission assembly. 
     
     
         11 . The system of  claim 9 , wherein the temperature regulation assembly is configured to cool at least one of the power end and the transmission assembly. 
     
     
         12 . The system of  claim 9 , wherein the temperature regulation assembly includes a fan and a radiator, the fan used to pass air over the radiator. 
     
     
         13 . The system of  claim 8 , wherein the transmission assembly includes a circulation fan to pass air over the plurality of electric motors. 
     
     
         14 . The system of  claim 8 , wherein the power end has a first end and a second end, the system further comprising a plurality of electric motors disposed at each of the first and second ends of the power end. 
     
     
         15 . The system of  claim 8 , wherein the plurality of electric motors comprise at least three electric motors radially spaced apart from one another about the crankshaft axis. 
     
     
         16 . The system of  claim 8 , wherein the plurality of gears comprises a bull gear, a planetary gear system driven by the bull gear and a plurality of spur gears engaging the bull gear, wherein each spur gear is coupled to a separate electric motor. 
     
     
         17 . The system of  claim 8 , further comprising:
 a platform coupled to the power end, the platform configured to elevate the power end above ground.   
     
     
         18 . The system of  claim 8 , wherein the power end is configured to convert rotary motion of an output spline driven by the transmission assembly into linear motion for use in a fluid end. 
     
     
         19 . An electric drive hydraulic fracturing pump system, comprising:
 a hydraulic fracturing pump having a power end with a pump crankshaft extending along a crankshaft axis;   at least three electric motors radially spaced apart from one another about the crankshaft axis, each electric motor having an electric motor output shaft coupled to the pump crankshaft; and   a reduction gear assembly coupling the output shafts of the electric motors to the pump crankshaft.   
     
     
         20 . The system of  claim 19 , wherein the power end has a first end and a second end; the system further comprising at least three electric motors disposed at each of the first and second ends of the power end and a gear reduction assembly disposed at each end of the first and second ends of the power end, wherein the at least three electric motors at each end of the power end are radially spaced about the crankshaft axis. 
     
     
         21 . The system of  claim 19 , further comprising a planetary assembly coupling the gear reduction assembly to the pump crankshaft. 
     
     
         22 . The system of  claim 20 , further comprising a planetary assembly disposed at each end of the power end and coupling a gear reduction assembly to the pump crankshaft. 
     
     
         23 . The system of  claim 19 ; wherein one or more motors comprises at least two electric motors stacked adjacent one another to drive an electric motor output shaft. 
     
     
         24 . The system of  claim 19 , further comprising a temperature regulation assembly disposed to regulate the temperature of the at least three electric motors. 
     
     
         25 . An electric drive hydraulic fracturing pump system, comprising:
 a hydraulic fracturing pump;   a plurality of motors positioned to power the hydraulic fracturing pump; and   a planetary gear train having a plurality of input pinion gears in rotational contact with each of the plurality of motors.   
     
     
         26 . The system of  claim 25 , further comprising a control module configured to regulate performance of the plurality of motors by controlling one or more of power output and speed of each motor, either simultaneously as a group at a selected power level and/or independently wherein operation of each motor is independent of the operation of other motors with respect to at least power output and runtime.