Compressor

Abstract

A compressor ( 1 ) includes communication holes ( 83 ) penetrating through a valve plate ( 9 ) at positions opposite to regulation steps of a cylinder block ( 2 ) and communicating cylinder bores ( 3 ) and suction chamber ( 7 ), a rotary valve ( 71 ) configured to rotate with the drive shaft ( 10 ) and be in rotational slide contact with a suction chamber side of the valve plate ( 9 ) as covering the communication holes ( 83 ) of the valve plate ( 9 ). The rotary valve ( 71 ) is formed with a residual pressure release passage ( 71 c ). As the rotary valve ( 71 ) rotates, the residual pressure release passage ( 71 c ) connects by turns one of the communication holes ( 83 ) communicating with one of the cylinder bores ( 3 ) having finished discharge and another of the communication holes ( 83 ) communicating with another of cylinder bores ( 3 ) having lower pressure than the one of the cylinder bores ( 3 ).

1 . A compressor, comprising:
 a cylinder block formed with cylinder bores spaced away each other in an interval in a circumferential direction of the cylinder block around a drive shaft;   a housing attached to the cylinder block via a valve plate and forming a suction chamber therein, the valve plate formed with suction holes penetrating therethrough;   reed type suction valves arranged on a cylinder bore side of the valve plate and configured to open and close the suction holes; regulation steps provided at peripheries of the cylinder bores and recessed from a side of the cylinder block where the valve plate is attached, the regulation steps configured to limit maximum lift positions of the suction valves;   pistons configured to reciprocate in the cylinder bores as the drive shaft rotates so as to carry out a suction stroke and a discharge stroke by turns in the cylinder bores;   communication holes penetrating through the valve plate at positions opposite to the regulation steps, the communication holes communicating the cylinder bores and the suction chamber; a rotary valve configured to rotate with the drive shaft and be in rotational slide contact with a suction chamber side of the valve plate with covering the communication holes of the valve plate; and   a residual pressure release passage configured to connect one of the communication holes communicating with one of the cylinder bores having finished discharge and another of the communication holes communicating with another of cylinder bores having lower pressure than the one of the cylinder bores by turns, as the rotary valve rotates.   
   
   
       2 . The compressor according to  claim 1 , wherein
 annular grooves are formed around the suction holes on the cylinder bore side of the valve plate, and the communication holes are formed in the annular grooves.   
   
   
       3 . The compressor according to  claim 1 , wherein
 the residual pressure release passage is formed with two or more outlet ports.   
   
   
       4 . The compressor according to  claim 1 , wherein
 the drive shaft extends into the suction chamber through a through hole extending through the valve plate, and the rotary valve is directly or indirectly connected to the drive shaft so as to rotate with the drive shaft together.   
   
   
       5 . The compressor according to  claim 4 , further comprising
 a stopper fixed to the drive shaft so as to rotate with the drive shaft in the suction chamber,   wherein the rotary valve is axially slidably and rotatably fitted to the drive shaft and is axially slidably and unrotatably fitted to the stopper so that the rotary valve rotates with the drive shaft, and wherein the rotary valve is biased toward the valve plate by the elastic member compressed between the stopper and the rotary valve.