Variable Displacement Type Reciprocating Compressor

Abstract

The power conversion mechanism of a variable displacement reciprocating compressor includes a joint shaft ( 54 ) that is fitted to a drive shaft ( 30 ) through a bearing ( 56 ) and supported by an inner circumferential face of a support hole ( 58 ) formed in the cylinder block ( 20 ) so as not to be relatively rotatable but to be slidable relative to the inner circumferential face; a joint case ( 66 ) that is integrally and tiltably formed in the conversion mechanism ( 38 ); and a plurality of balls ( 74 ) rollably held between JS-side protrusions that are integrally formed in the joint shaft ( 54 ) and JC-side protrusions ( 62 ) that are integrally formed in the join case ( 66 ). The variable suction throttle mechanism of the compressor uses the sliding movement of the joint shaft ( 54 ) to change air-flow resistance in a valve chamber ( 101 ) communicating with the support hole ( 58 ).

1 . A variable displacement reciprocating compressor comprising:
 a housing in which a suction chamber, a discharge chamber and a crank chamber are partitioned, and a suction port and a discharge port connecting each of the suction and discharge chambers to the outside are formed;   a cylinder block that is placed in the housing and provided with a plurality cylinder bores formed on a concentric circle, which lead to the suction chamber via a suction valve and to the discharge chamber via a discharge valve;   a power conversion mechanism that converts the rotation of a drive shaft stretching through the crank chamber into a reciprocating movement of a piston situated in the cylinder bore by varying stroke length; and   a variable suction throttle mechanism that is interposed in a suction path stretching from the suction port to the suction chamber, and is changed in air-flow resistance according to the stroke length of the piston, wherein:   the suction path includes a space that is created in a radial center of the cylinder block;   the power conversion mechanism includes:   a ring-like cam member that is connected through a hinge to an outer circumferential portion of a rotor fitted to the drive shaft, penetrated by the drive shaft, and is capable of tilting relative to the drive shaft while moving in an axial direction of the drive shaft;   a conversion mechanism that is connected to the piston via a coupling mechanism and converts a tilt angle of the cam member into a reciprocating movement of the piston;   a joint shaft that is fitted to the drive shaft through a bearing, and is supported by an inner circumferential face of a support hole formed in the cylinder block and leading to the space, so as not to be relatively rotatable but to be slidable relative to the inner circumferential face;   a joint case that is integrally and tiltably formed in the conversion mechanism; and   a plurality of balls rollably held between JS-side protrusions that are integrally formed in the joint shaft and JC-side protrusions that are integrally formed in the join case, and   the variable suction throttle mechanism uses the sliding movement of the joint shaft to change air-flow resistance in the space serving as a valve chamber.   
     
     
         2 . The variable displacement reciprocating compressor according to  claim 1 , wherein the variable suction throttle mechanism is integrally formed in the joint shaft, and has an air-flow resistance increasing member that enters the space to reduce a channel sectional area of the suction path within the space.