Piston type compressor

Abstract

The piston type compressor includes a cylinder block, a rotary shaft, a plurality of pistons, a rotary valve and radial load transmission means. The radial load transmission means transmits a radial load caused by compression reaction force acting on the piston, which is on its compression stroke of the discharge stroke, to the rotary valve, thereby pressing the rotary valve against an inner peripheral surface of the valve chamber. The radial load transmission means has a direction turning portion for turning the radial load toward the inner peripheral surface of the valve chamber between the suction port communicating with the cylinder bore whose piston has completed the discharge stroke and the suction port communicating with the cylinder bore whose piston is on the compression stroke in a rotation direction of the rotary valve from the suction port communicating with the cylinder bore whose piston has completed the discharge stroke.

1 . A piston type compressor comprising: 
 a cylinder block having a valve chamber, a plurality of cylinder bores formed around the valve chamber and a plurality of suction ports, wherein each suction port connects the valve chamber and the respective cylinder bore;    a rotary shaft rotatably supported in the cylinder block,    a plurality of pistons, each of which is received in the respective cylinder bore and is reciprocated therein in accordance with rotation of the rotary shaft;    a rotary valve received in the valve chamber and connected to the rotary shaft so as to be rotated in accordance with the rotation of the rotary shaft, thereby selectively closing the suction port communicating with the cylinder bore whose piston is on its discharge stroke; and    radial load transmission means for transmitting a radial load caused by compression reaction force acting on the piston, which is on its compression stroke or the discharge stroke, to the rotary valve, thereby pressing the rotary valve against an inner peripheral surface of the valve chamber, wherein the radial load transmission means has a direction turning portion for turning the radial load toward the inner peripheral surface of the valve chamber between the suction port communicating with the cylinder bore whose piston has completed the discharge stroke and the suction port communicating with the cylinder bore whose piston is on the compression stroke in a rotation direction of the rotary valve from the suction port communicating with the cylinder bore whose piston has completed the discharge stroke.    
   
   
       2 . The piston type compressor according to  claim 1 , wherein the direction turning portion is formed by integrally fixing the rotary valve to the rotary shaft so that the rotary valve is eccentric with respect to an axis of the rotary shaft.  
   
   
       3 . The piston type compressor according to  Claim 1 , wherein an eccentric pin is formed on an end of the rotary shaft on a side of the rotary valve between the suction port communicating with the cylinder bore whose piston has completed the discharge stroke and the suction port communicating with the cylinder bore whose piston is on the compression stroke in the rotation direction of the rotary valve from the suction port communicating with the cylinder bore whose piston has completed the discharge stroke, and the direction turning portion is formed by loosely fitting the rotary valve an the eccentric pin.  
   
   
       4 . The piston type compressor according to  claim 1 , wherein a flat pin, having a flat cross section and an elongated shape extending in a radial direction perpendicular to a radial direction of the inner peripheral surface of the valve chamber between the suction port communicating with the cylinder bore whose piston has completed the discharge stroke and the suction port communicating with the cylinder bore whose piston is on the compression stroke in the rotation direction of the rotary valve from the suction port communicating with the cylinder bore whose piston has completed the discharge stroke, is formed on an end of the rotary shaft on a side of the rotary valve, and the direction turning portion is formed by loosely fitting the rotary valve on the flat pin so as to be capable of sliding only along the radial direction in which the elongated shape of the flat pin extends.  
   
   
       5 . The piston type compressor according to  claim 1 , further comprising a bearing near the valve chamber for rotatably supporting the rotary shaft, wherein the difference between an inside diameter of the valve chamber and an outside diameter of the rotary valve is smaller than the difference between an inside diameter of the bearing and an outside diameter of the rotary shaft.  
   
   
       6 . The piston type compressor according to  claim 1 , further comprising a coating near the valve chamber for rotatably supporting the rotary shaft wherein the difference between an inside diameter of the valve chamber and an outside diameter of the rotary valve is smaller than the difference between an inside diameter of the coating and an outside diameter of the rotary shaft.