Multiple motor drivers for a hermetically-sealed motor-compressor system

Abstract

A fluid compression system is disclosed having a hermetically-sealed housing with at least two motors and a compressor arranged therein. The motors may be arranged either on both sides of the compressor or in a tandem configuration on one side of the compressor. The motors may be adapted to drive both the compressor and at least one blower device coupled to a free end of shaft that extends through the housing, the blower device being configured to circulate a cooling fluid throughout the housing and thereby cool the motors and any accompanying radial/axial bearings.

1 . A fluid compression system, comprising:
 a hermetically-sealed housing having a multi-section shaft extending from a first end of the housing to a second end of the housing;   a compressor arranged within the housing and including a driven section of the shaft;   a first motor being disposed within the housing axially-adjacent the compressor at the first end, the first motor including a first motor rotor section of the shaft;   a second motor disposed within the housing axially-adjacent the compressor at the second end, the second motor including a second motor rotor section of the shaft, wherein the first and second motor rotor sections are coupled to the driven section at opposing ends such that the motors are configured to simultaneously drive the driven section of the shaft and thereby rotate the compressor;   radial bearings disposed proximal each end of the first and second motor rotor sections and each end of the driven section, the radial bearings being in fluid communication with at least one internal cooling passage defined within the housing; and   a first impeller coupled to a free end of the second motor rotor section of the shaft, whereby rotation of the second motor rotor section drives the first impeller and circulates a cooling fluid in a closed cooling loop through internal cooling passages defined within the housing.   
     
     
         2 . (canceled) 
     
     
         3 . The fluid compression system of  claim 1 , further comprising a second impeller coupled to a free end of the first motor rotor section of the shaft, whereby rotation of the first motor rotor section drives the second impeller and circulates the cooling fluid in the closed cooling loop through the internal cooling passages. 
     
     
         4 . The fluid compression system of  claim 1 , wherein the radial bearings are magnetic bearings. 
     
     
         5 . The fluid compression system of  claim 1 , further comprising a separator axially-spaced from the compressor and disposed within the housing, the separator being coupled to the driven section of the shaft. 
     
     
         6 . The fluid compression system of  claim 1 , wherein the first motor rotor section and the driven section are connected via a first coupling. 
     
     
         7 . The fluid compression system of  claim 6 , wherein the second motor rotor section and the driven section are connected via a second coupling. 
     
     
         8 . The fluid compression system of  claim 1 , wherein the compressor is a multi-stage centrifugal compressor. 
     
     
         9 . A method of compressing a fluid, comprising:
 disposing a first motor, a second motor, and a compressor within a hermetically-sealed housing, the housing having a shaft that extends from a first end of the housing to a second end of the housing, and wherein the first and second motors and the compressor are each coupled to the shaft;   rotating the shaft with the first motor to provide torque to the shaft and drive the compressor at a first power/torque level; and   rotating the shaft with the second motor concurrently with the first motor to provide additional torque to the shaft and drive the compressor at a second power/torque level, wherein the second power/torque level is greater than the first power/torque level.   
     
     
         10 . The method of  claim 9 , further comprising:
 supporting the shaft within the housing with a plurality of radial bearings, the housing defining a plurality of internal cooling passages in fluid communication with the plurality of radial bearings and the first and second motors;   driving a first impeller coupled to a first free end of the shaft;   circulating a cooling fluid through at least one of the internal cooling passages of the housing with the first impeller;   cooling the first and second motors and the plurality radial bearings with the cooling fluid; and   returning the cooling fluid to the impeller in a closed-loop circuit.   
     
     
         11 . The method of  claim 10 , further comprising:
 driving a second impeller coupled to a second free end of the shaft;   circulating the cooling fluid through at least one of the internal cooling passages of the housing with the second impeller;   cooling the first and second motors and the plurality radial bearings with the cooling fluid; and   returning the cooling fluid to the second impeller in the closed-loop circuit.   
     
     
         12 . The method of  claim 11 , further comprising directing the cooling fluid through a heat exchanger to reduce the temperature of the cooling fluid. 
     
     
         13 . The method of  claim 12 , further comprising filtering the cooling fluid with a gas conditioning skid. 
     
     
         14 . The method of  claim 10 , further comprising cooling an axial thrust bearing with the cooling fluid, the axial thrust bearing being disposed on the shaft between the compressor and the first motor. 
     
     
         15 . The method of  claim 10 , further comprising separating high-density components from low-density components in the fluid with an integrated separator arranged within the housing and axially-spaced from the compressor, the integrated separator being coupled to the shaft such that rotation of the shaft drives the integrated separator. 
     
     
         16 . A fluid compression system, comprising:
 a hermetically-sealed housing having a shaft extending from a first end of the housing to a second end of the housing;   a compressor arranged within the housing at the first end and including a driven section of the shaft;   a first motor disposed within the housing at the second end and axially-offset from the compressor, the first motor including a first motor rotor section of the shaft and being in fluid communication with at least one internal cooling passage;   a second motor disposed within the housing interposing the compressor and the first motor, the second motor including a second motor rotor section of the shaft and being in fluid communication with at least one internal cooling passage, wherein the first and second motors are configured to drive the driven section of the shaft in tandem and thereby rotate the compressor;   radial bearings disposed proximal each end of the first and second motor rotor sections and each end of the driven section, the radial bearings being in fluid communication with at least one internal cooling passage; and   a first impeller coupled to a free end of the first motor rotor section of the shaft, whereby rotation of the first motor rotor section drives the first impeller and circulates a cooling fluid in a closed cooling loop through the internal cooling passages.   
     
     
         17 . The fluid compression system of  claim 16 , further comprising:
 a first coupling connecting the first motor rotor section to the second motor rotor section; and   a second coupling connecting the second motor rotor section to the driven section.   
     
     
         18 . (canceled) 
     
     
         19 . The fluid compression system of  claim 16 , further comprising a second impeller coupled to the second motor rotor section of the shaft and disposed between the first and second motors, whereby rotation of the second motor rotor section drives the second impeller and circulates the cooling fluid in the closed cooling loop through the internal cooling passages. 
     
     
         20 . The fluid compression system of  claim 16 , further comprising a separator axially-spaced from the compressor and disposed within the housing, the separator being coupled to the driven section of the shaft. 
     
     
         21 - 30 . (canceled) 
     
     
         31 . The method of  claim 12 , further comprising filtering the cooling fluid with a gas conditioning skid. 
     
     
         32 - 37 . (canceled)