Compressor Having Capacity Modulation System

Abstract

A compressor may include first and second scrolls and a capacity-modulation system. The first and second scrolls include first and second end plates and first and second spiral wraps. The second end plate may define a suction inlet, a discharge passage, a modulation port, and a vent passage. The capacity-modulation system may include a control valve and a piston. The control valve is movable between first and second positions. The piston may be disposed within a recess in the second end plate and is movable between an open position in which communication between the modulation port and the vent passage is allowed and a closed position in which communication between the modulation port and the vent passage is prevented. Moving the control valve to the first position moves the piston to the closed position. Moving the control valve to the second position moves the piston to the open position.

1 . A compressor comprising:
 a first scroll having a first end plate and a first spiral wrap extending from the first end plate;   a second scroll having a second end plate and a second spiral wrap extending from the second end plate, wherein the first and second spiral wraps cooperate to define a plurality of fluid pockets, and wherein during operation of the compressor, the fluid pockets move from a radially outer position to radially intermediate positions to a radially inner position; and   a capacity-modulation system operable in a high-capacity mode and a low-capacity mode,   wherein:
 the second end plate defines a suction inlet, a discharge passage, a modulation port, and a vent passage, 
 the modulation port communicates with one of the fluid pockets at one of the radially intermediate positions, and 
 the vent passage extends from and is in direct communication with the suction inlet defined by the second scroll; 
 the capacity-modulation system includes a control valve and a piston, 
 the control valve is movable between a first position and a second position, 
 the piston is disposed within a recess in the second end plate, 
 the vent passage extends from the recess to the suction inlet, 
 the piston is movable in the recess between an open position in which fluid communication between the modulation port and the vent passage is allowed and a closed position in which fluid communication between the modulation port and the vent passage is prevented, and 
 movement of the control valve to the first position causes movement of the piston to the closed position, and movement of the control valve to the second position causes movement of the piston to the open position. 
   
     
     
         2 . The compressor of  claim 1 , wherein the second end plate includes another modulation port that communicates with another one of the fluid pockets at another one of the radially intermediate positions. 
     
     
         3 . The compressor of  claim 2 , wherein the piston blocks both of the modulation ports in the closed position and opens both of the modulation ports in the open position. 
     
     
         4 . The compressor of  claim 3 , wherein the piston includes a recess formed in an axially-facing surface of the piston, wherein the axially-facing surface sealingly contacts a surface of the non-orbiting scroll when the piston is in the closed position. 
     
     
         5 . The compressor of  claim 4 , wherein the recess in the piston is vented to the vent passage. 
     
     
         6 . The compressor of  claim 5 , wherein a spring is disposed within the recess. 
     
     
         7 . The compressor of  claim 3 , wherein:
 when the control valve is in the first position, the control valve allows intermediate-pressure working fluid to flow to an actuation chamber defined by the piston and the second end plate,   when the control valve is in the second position, the control valve prevents intermediate-pressure working fluid from flowing to the actuation chamber, and   the intermediate-pressure working fluid is at a pressure higher than a suction pressure and less than a discharge pressure.   
     
     
         8 . The compressor of  claim 7 , wherein:
 when the control valve is in the first position, the intermediate-pressure working fluid flows from an axial biasing chamber, through the control valve to the actuation chamber via a passage in the second end plate, and   the axial biasing chamber is defined by the second end plate and a floating seal assembly.   
     
     
         9 . (canceled) 
     
     
         10 . The compressor of  claim 8 , wherein the second end plate includes a first portion and a second portion that is attached to the first portion by fasteners, and wherein the second portion defines a closed end of the actuation chamber. 
     
     
         11 . The compressor of  claim 7 , wherein:
 the control valve includes a body, a housing, and a valve member,   the body is received in a valve passage in the second end plate,   the body includes a first passage, a second passage, and a third passage,   the housing is fixed relative to the second end plate and the body, and   the valve member is disposed within the housing and is movable therein between the first and second positions.   
     
     
         12 . The compressor of  claim 11 , wherein:
 a portion of the valve member is movably received in the first passage of the body,   when the valve member is in the first position, the valve member allows fluid communication between the second and third passages and prevents fluid communication between the first passage and a suction chamber of the compressor, and   when the valve member is in the second position, the valve member prevents fluid communication between the second and third passages and allows fluid communication between the first passage and the suction chamber of the compressor.   
     
     
         13 . (canceled) 
     
     
         14 . A compressor comprising:
 a first scroll having a first end plate and a first spiral wrap extending from the first end plate;   a second scroll having a second end plate and a second spiral wrap extending from the second end plate, wherein the first and second spiral wraps cooperate to define a plurality of fluid pockets, wherein during operation of the compressor, the fluid pockets move from a radially outer position to radially intermediate positions to a radially inner position, wherein the second end plate includes a first modulation port, a second modulation port, a first recess, a second recess, and a discharge passage, and wherein the first and second modulation ports fluidly communicate with respective fluid pockets at the radially intermediate positions; and   a capacity-modulation system operable to switch the compressor among a high-capacity mode, an intermediate-capacity mode, and a low-capacity mode,   wherein:
 the capacity-modulation system includes a first piston, a second piston, a first control valve, and a second control valve, 
 the first and second control valves are movable between a first position and a second position, 
 the first and second pistons are disposed within the first and second recesses, respectively, and are movable therein between an open position and a closed position, 
 when the first and second pistons are in the open position, fluid communication is allowed between the first and second modulation ports and a suction-pressure region of the compressor, 
 when the first and second pistons are in the closed position, fluid communication is prevented between the first and second modulation ports and the suction-pressure region of the compressor, 
 movement of the first control valve to the first position causes movement of the first piston to the closed position, and movement of the first control valve to the second position causes movement of the first piston to the open position, and 
 movement of the second control valve to the first position causes movement of the second piston to the closed position, and movement of the second control valve to the second position causes movement of the second piston to the open position. 
   
     
     
         15 . The compressor of  claim 14 , wherein the suction-pressure region of the compressor is a suction inlet defined by the second scroll. 
     
     
         16 . The compressor of  claim 14 , wherein:
 the compressor is in the high-capacity mode when the first and second pistons are in the closed position and the first and second control valves are in the first position,   the compressor is in the intermediate-capacity mode when one of the first and second pistons is in the closed position, one of the first and second pistons is in the open position, one of the first and second control valves is in the first position, and one of the first and second control valves is in the second position, and   the compressor is in the low-capacity mode when the first and second pistons are in the open position and the first and second control valves are in the second position.   
     
     
         17 . The compressor of  claim 16 , wherein the second end plate includes a connecting passage that extends from the first recess to the second recess, and wherein the connecting passage is in fluid communication with the first and second recesses when the first and second pistons are in the open position. 
     
     
         18 . The compressor of  claim 16 , wherein:
 each of the first and second control valves includes a body, a housing, and a valve member,   the body is received in a respective valve passage in the second end plate,   the body includes a first passage, a second passage, and a third passage,   the housing is fixed relative to the second end plate and the body, and   the valve member is disposed within the housing and is movable therein between the first and second positions.   
     
     
         19 .- 20 . (canceled) 
     
     
         21 . A compressor comprising:
 a first scroll having a first end plate and a first spiral wrap extending from the first end plate;   a second scroll having a second end plate and a second spiral wrap extending from the second end plate, wherein the first and second spiral wraps cooperate to define a plurality of fluid pockets, wherein during operation of the compressor, the fluid pockets move from a radially outer position to radially intermediate positions to a radially inner position, wherein the second end plate includes a first modulation port, a second modulation port, a first recess, a second recess, and a discharge passage, and wherein the first and second modulation ports fluidly communicate with respective fluid pockets at the radially intermediate positions; and   a capacity-modulation system including a first piston, a second piston, and a control valve,   wherein:
 the first and second pistons are disposed within the first and second recesses, respectively, and are movable therein between an open position and a closed position, 
 when the first and second pistons are in the open position, fluid communication is allowed between the first and second modulation ports and a suction-pressure region of the compressor, 
 when the first and second pistons are in the closed position, fluid communication is prevented between the first and second modulation ports and the suction-pressure region of the compressor, 
 movement of the control valve to a first position causes movement of the first and second pistons to the closed position, and movement of the control valve to a second position causes movement of the first and second pistons to the open position. 
   
     
     
         22 . The compressor of  claim 21 , wherein the suction-pressure region of the compressor is a suction inlet defined by the second scroll. 
     
     
         23 . The compressor of  claim 21 , wherein the second end plate includes a connecting passage that extends from the first recess to the second recess, and wherein the connecting passage is in fluid communication with the first and second recesses when the first and second pistons are in the open position. 
     
     
         24 . The compressor of  claim 21 , wherein:
 the control valve includes a body, a housing, and a valve member,   the body is received in a respective valve passage in the second end plate,   the body includes a first passage, a second passage, and a third passage,   the housing is fixed relative to the second end plate and the body,   the valve member is disposed within the housing and is movable therein between the first and second positions,   a portion of the valve member is movably received in the first passage of the body,   when the valve member is in the first position. the valve member allows fluid communication between the second and third passages and prevents fluid communication between the first passage and a suction chamber of the compressor, and   when the valve member is in the second position, the valve member prevents fluid communication between the second and third passages and allows fluid communication between the first passage and the suction chamber of the compressor.   
     
     
         25 .- 49 . (canceled)