Chiller Compressor Rolling Bearings with Squeeze Film Dampers

Abstract

A centrifugal compressor ( 22 ) comprises: a case ( 160 ) having a suction port ( 24 ) and a discharge port ( 26 ); an impeller ( 162, 164 ) mounted for rotation about an impeller axis ( 500 ) by a plurality of bearings ( 80, 82 ); and a motor ( 34 ) coupled to the impeller to drive rotation of the impeller about the impeller axis. The bearings each comprise: an inner race ( 200 ); an outer race ( 202 ); and rolling elements ( 204 ) between the inner race and outer race. The outer race of each bearing is mounted for radial displacement relative to the case and is surrounded by an associated chamber ( 224 ); and the chambers are coupled to a port ( 92 ) on the compressor.

1 . (canceled) 
     
     
         2 . The system of  claim 9  wherein:
 the impeller is coaxial with the motor and mounted to a shaft ( 166 ) of the rotor for said rotation about the impeller axis. 
 
     
     
         3 . The system of  claim 9  wherein:
 the centrifugal compressor is an in-line compressor with a first said impeller and a second said impeller; and 
 a first said bearing is between the motor and the first impeller and second impeller. 
 
     
     
         4 . The system of  claim 9  wherein:
 each of the chambers is bounded by:
 a portion of the case; 
 the outer race; and 
 a pair of o-rings ( 226 ,  228 ). 
 
 
     
     
         5 . The system of  claim 9  further comprising:
 at least one orifice ( 250 ) between the port and the chambers. 
 
     
     
         6 . The system of  claim 9  wherein each of the bearings further comprises:
 an anti-rotation means ( 240 ) coupling the outer race to the case. 
 
     
     
         7 . The system of  claim 9  further comprising:
 a drain port ( 104 ) coupled to the chambers. 
 
     
     
         8 . (canceled) 
     
     
         9 . A refrigeration system ( 20 ) comprising:
 a centrifugal compressor ( 22 ) comprising:
 a case ( 160 ) having a suction port ( 24 ) and a discharge port ( 26 ); 
 an impeller ( 162 ,  164 ) mounted for rotation about an impeller axis ( 500 ) by a plurality of bearings ( 80 ,  82 ), the bearings each comprising:
 an inner race ( 200 ); 
 an outer race ( 202 ); and 
 rolling elements ( 204 ) between the inner race and outer race; and 
 
 a motor ( 34 ) coupled to the impeller to drive rotation of the impeller about the impeller axis, wherein:
 the outer race of each bearing is mounted for radial displacement relative to the case and is surrounded by an associated chamber ( 224 ); and 
 the chambers are coupled to a port ( 92 ) on the compressor; 
 
   a heat rejection heat exchanger ( 38 ) coupled to the compressor to receive refrigerant from the discharge port;   an expansion device ( 56 );   a heat absorption heat exchanger ( 64 ) coupled to the compressor to deliver refrigerant to the suction port; and   a bearing supply flowpath ( 90 ) to said port ( 92 ) bypassing the expansion device ( 56 ).   
     
     
         10 . The system of  claim 9  further comprising:
 subcooling means ( 120 ,  144 ) for subcooling refrigerant flowing along the bearing supply flowpath. 
 
     
     
         11 . The system of  claim 10  wherein:
 the subcooling means comprises a heat exchanger ( 120 ). 
 
     
     
         12 . The system of  claim 11  wherein:
 the heat exchanger ( 120 ) is a refrigerant-refrigerant heat exchanger having a first leg ( 122 ) along the bearing supply flowpath and a second leg ( 124 ) in heat exchange with the first leg. 
 
     
     
         13 . The system of  claim 11  wherein:
 the second leg is along a branch flowpath ( 140 ) branching off from and returning to a main flowpath ( 35 ); and 
 the subcooling means further comprises a second expansion device ( 144 ) along the branch flowpath ( 140 ) upstream of the second leg. 
 
     
     
         14 . The system of  claim 10  further comprising a filter ( 126 ) between the subcooling means and the port. 
     
     
         15 . The system of  claim 10  wherein:
 at least one orifice ( 250 ) in the compressor restricts flow through the bearing supply flowpath. 
 
     
     
         16 . The system of  claim 10  further comprising:
 a drain flowpath ( 100 ) from the chambers. 
 
     
     
         17 . The system of  claim 16  further comprising:
 a pressure control valve ( 110 ) in the drain flowpath. 
 
     
     
         18 . The system of  claim 16  wherein:
 the drain flowpath extends to the heat absorption heat exchanger to merge with a main flowpath ( 35 ). 
 
     
     
         19 . A method for using a refrigeration system, the refrigeration system comprising:
 a centrifugal compressor ( 22 ) comprising:
 a case ( 160 ) having a suction port ( 24 ) and a discharge port ( 26 ); 
 an impeller ( 162 ,  164 ) mounted for rotation about an impeller axis ( 500 ) by a plurality of bearings ( 80 ,  82 ), the bearings each comprising:
 an inner race ( 200 ); 
 an outer race ( 202 ); and 
 rolling elements ( 204 ) between the inner race and outer race; and 
 
 a motor ( 34 ) coupled to the impeller to drive rotation of the impeller about the impeller axis; 
   a heat rejection heat exchanger ( 38 ) coupled to the compressor to receive refrigerant from the discharge port;   an expansion device ( 56 ); and   a heat absorption heat exchanger ( 64 ) coupled to the compressor to deliver refrigerant to the suction port,   wherein:   the outer race of each bearing is mounted for radial displacement relative to the case and is surrounded by an associated chamber ( 224 ); and   the chambers are coupled to a port ( 92 ) on the compressor,   the method comprising:   running the compressor to drive refrigerant along a main flowpath proceeding sequentially from the compressor to the heat rejection heat exchanger, the expansion device, and the heat absorption heat exchanger to return to the compressor; and   diverting refrigerant from the main flowpath to the chambers.   
     
     
         20 . The method of  claim 19  further comprising:
 subcooling the diverted refrigerant prior to delivery to the chambers. 
 
     
     
         21 . The method of  claim 19  further comprising:
 draining refrigerant from the chambers by a drain port ( 104 ) coupled to the chambers. 
 
     
     
         22 . The method of  claim 19  the diverting comprises:
 passing refrigerant through at least one orifice ( 250 ) located between the port and the chambers.