Scroll compressor

Abstract

To prevent or reduce functional disturbance of a back-pressure control valve caused by contamination, a scroll compressor includes: a scroll unit having a fixed scroll and an orbiting scroll; a discharge chamber (H3) into which fluid compressed by the scroll unit is discharged; a back-pressure chamber (H4) configured to apply a back pressure that presses the orbiting scroll against the fixed scroll; and a switching valve (900) disposed at some midpoint of a back-pressure supply passage (L1) connecting the discharge chamber (H3) and the back-pressure chamber (H4) in communication. The switching valve (900) is configured to switch between a first state in which the switching valve (900) connects the discharge chamber (H3) with the back-pressure chamber (H4) in communication and a second state in which the switching valve (900) connects the back-pressure chamber (H4) with a suction chamber (H1), in accordance with an operational state of the scroll unit.

1 . A scroll compressor comprising:
 a scroll unit having a fixed scroll and an orbiting scroll;   a discharge chamber into which fluid compressed by the scroll unit is discharged;   a back-pressure chamber configured to apply a back pressure that presses the orbiting scroll against the fixed scroll; and   a switching valve disposed at some midpoint of a communication passage connecting the discharge chamber and the back-pressure chamber in communication, and configured to switch between a first state and a second state in accordance with an operational state of the scroll unit, wherein the switching valve connects the discharge chamber with the back-pressure chamber in communication in the first state, and the switching valve connects the back-pressure chamber with a space external to the back-pressure chamber in communication in the second state.   
     
     
         2 . The scroll compressor according to  claim 1 , wherein the switching valve switches to the first state when the scroll unit is in operation, and switches to the second state when the scroll unit is not in operation. 
     
     
         3 . The scroll compressor according to  claim 1 , wherein the space external to the back-pressure chamber is a suction chamber into which fluid is drawn from an external device. 
     
     
         4 . The scroll compressor according to  claim 3 , wherein the switching valve switches between the first state and the second state in accordance with pressures in the discharge chamber, the back-pressure chamber, and the suction chamber. 
     
     
         5 . The scroll compressor according to  claim 1 , wherein the switching valve is located vertically below the back-pressure chamber. 
     
     
         6 . The scroll compressor according to  claim 2 , wherein the space external to the back-pressure chamber is a suction chamber into which fluid is drawn from an external device. 
     
     
         7 . The scroll compressor according to  claim 2 , wherein the switching valve is located vertically below the back-pressure chamber. 
     
     
         8 . The scroll compressor according to  claim 3 , wherein the switching valve is located vertically below the back-pressure chamber. 
     
     
         9 . The scroll compressor according to  claim 4 , wherein the switching valve is located vertically below the back-pressure chamber.