Variable displacement swash plate type compressor

Abstract

In the compressor of the present invention, a throttle hole is formed in a connection portion. The throttle hole extends from a control pressure chamber toward the inside of an outer sliding portion. In the compressor, when the pressure in the control pressure chamber is regulated, in addition to respective opening degree adjustments of a high-pressure passage and a low-pressure control valve, a refrigerant gas is discharged from the inside of the control pressure chamber to a swash plate chamber through the throttle hole. Lubricant is discharged from the throttle hole together with the refrigerant gas. Consequently, in the compressor, the lubricant is less easily stored in the control pressure chamber, and lubricant shortage in the swash plate chamber less easily occurs.

1 . A variable displacement swash plate type compressor comprising:
 a housing in which a suction chamber, a discharge chamber, a swash plate chamber, and a cylinder bore are formed;   a drive shaft rotatably supported by the housing;   a swash plate rotatable in the swash plate chamber according to the rotation of the drive shaft;   a link mechanism provided between the drive shaft and the swash plate and configured to allow a change in an inclination angle of the swash plate with respect to a direction orthogonal to an axis of the drive shaft;   a piston accommodated in the cylinder bore to be reciprocatingly movable;   a conversion mechanism configured to reciprocatingly move, according to the rotation of the swash plate, the piston in the cylinder bore at a stroke corresponding to the inclination angle;   an actuator capable of changing the inclination angle; and   a control mechanism configured to control the actuator, wherein   the swash plate chamber communicates with the suction chamber,   the actuator includes:
 a defining body provided on the drive shaft in the swash plate chamber; 
 a movable body movable in axial direction of the drive shaft in the swash plate chamber; and 
 a control pressure chamber defined by the defining body and the movable body and configured to move the movable body by an internal pressure in the control pressure chamber, 
   the control mechanism includes:
 a supply passage communicating with the discharge chamber and the control pressure chamber, and introducing a refrigerant in the discharge chamber into the control pressure chamber; and 
 a bleed passage communicating with the control pressure chamber and the swash plate chamber, and discharging the refrigerant in the control pressure chamber to the swash plate chamber, and 
   the bleed passage includes a communication path formed in at least one of the movable body and the defining body, and discharging lubricant from the control pressure chamber to the swash plate chamber together with the refrigerant.   
     
     
         2 . The variable displacement swash plate type compressor according to  claim 1 , wherein
 the defining body includes an outer sliding portion extending in the axial direction of the drive shaft and surrounding slidably the movable body;   the movable body includes:
 a first cylinder portion arranged near the swash plate around the drive shaft; 
 a second cylinder portion formed in a cylindrical shape expanded to be larger in a diameter than the first cylinder portion; and 
 a connection portion connected the first cylinder portion and the second cylinder portion, and 
   the communication path is formed in the second cylinder portion or the coupling portion such that the lubricant discharged from the communication path together with the refrigerant is supplied to a sliding part between the movable body and the outer sliding portion.   
     
     
         3 . The variable displacement swash plate type compressor according to  claim 1 , wherein
 the defining body is fixed to the drive shaft,   a thrust bearing that receives a thrust force acting on the drive shaft is provided between the defining body and the housing,   a radial bearing that receives a radial force acting on the drive shaft is provided between the housing and the drive shaft,   a shaft seal device that secures seal between an inside of the housing and an outside is provided between the housing and the drive shaft, and   the communication path is formed in the defining body such that the lubricant discharged from the communication path together with the refrigerant is supplied to the thrust bearing, the radial bearing, or the shaft seal device.   
     
     
         4 . The variable displacement swash plate type compressor according to  claim 1 , wherein
 the movable body includes a peripheral wall that extends in the axial direction of the drive shaft and surrounds the defining body while sliding with the defining body and a bottom wall that extends from the peripheral wall toward the drive shaft, and   the communication path is formed in the defining body such that the lubricant discharged from the communication path together with the refrigerant is supplied to a sliding part between the peripheral wall and the defining body.   
     
     
         5 . The variable displacement swash plate type compressor according to  claim 1 , wherein
 the movable body includes a peripheral wall that extends in the axial direction of the drive shaft and surrounds the defining body while sliding with the defining body and a bottom wall that extends from the peripheral wall toward the drive shaft,   a thrust bearing that receives a thrust force acting on the drive shaft is provided between the movable body and the housing, and   the communication path is formed in the movable body such that the lubricant discharged from the communication path together with the refrigerant is supplied to the thrust bearing.