Wobble Plate Type Variable Displacement Compressor

Abstract

The whirling vibration of a rotating main shaft is reduced to decrease abnormal wear of a wobble plate rotation preventing mechanism, so that durability is improved. A inner ring 27 of a wobble plate rotation preventing mechanism 21 has a first support portion 52 of which an outer peripheral surface is supported by an inner peripheral surface of a guide hole 2 A of a cylinder block 2 and a second support portion 53 of which an inner peripheral surface supports the rotating main shaft via a plain bearing 51 , and the first support portion 52 and the second support portion 53 are arranged to overlap within a range from a minimum inclination angle of a swash plate 8 to a maximum inclination angle of the swash plate 8 in an axial direction of a rotating main shaft 5.

1 . A wobble plate type variable displacement compressor comprising:
 a rotating main shaft of which a front end side and a rear end side are rotatably supported by a housing;   a swash plate which synchronously rotates with the rotating main shaft and is inclinable with respect to the rotating main shaft;   a wobble plate which swings along with the rotation of the swash plate with respect to the rotating main shaft to reciprocate a piston in a cylinder bore; and   a wobble plate rotation preventing mechanism which is disposed at a middle portion of the rotating main shaft, and prevents the wobble plate from rotating at the time of rotating the rotating main shaft,   an inclination angle of the swash plate with respect to the rotating main shaft being varied to control a stroke amount of the piston,   wherein the wobble plate rotation preventing mechanism including:   a guide member which includes a first support portion of which an outer peripheral surface is supported by an inner peripheral surface of a guide hole in the housing to be movable in an axial direction of the rotating main shaft and prevented from rotating around the rotating main shaft; and   a connecting mechanism which connects the wobble plate to the guide member so that the wobble plate is swingable with respect to the guide member and rotation preventing force of the guide member is transmitted,   the guide member further including a second support portion of which an inner peripheral surface supports the rotating main shaft, and   the first support portion and the second support portion being arranged to overlap in the axial direction of the rotating main shaft.   
     
     
         2 . The wobble plate type variable displacement compressor according to  claim 1 , wherein the first support portion and the second support portion is arranged to overlap within a range from a minimum inclination angle of the swash plate to a maximum inclination angle of the swash plate in the axial direction of the rotating main shaft. 
     
     
         3 . The wobble plate type variable displacement compressor according to  claim 1 , wherein the connecting mechanism which connects the wobble plate to the guide member is a constant velocity universal joint. 
     
     
         4 . The wobble plate type variable displacement compressor according to  claim 3 , wherein the connecting mechanism includes:
 a plurality of guide grooves formed on the guide member for guiding balls provided for power transmission;   a supporting member which has a plurality of guide grooves for guiding the balls at positions facing the respective guide grooves of the guide member and which fixedly supports the wobble plate on an outer peripheral portion of the supporting member and rotatably supports the swash plate on an outer peripheral portion of the supporting member via a bearing;   a plurality of balls which is held by the guide grooves facing each other and performs power transmission by being compressed between the guide grooves; and   a sleeve which swingably supports the supporting member and is engaged with the guide member to be movable in the axial direction together therewith on the rotating main shaft, and of which an inner peripheral surface supports the rotating main shaft.   
     
     
         5 . The wobble plate type variable displacement compressor according to  claim 1 , wherein the connecting mechanism which connects the wobble plate to the guide member is a universal joint.