Variable displacement swash-plate compressor

Abstract

A variable displacement swash-plate compressor includes an actuator that is configured to change the inclination angle of a swash plate. The actuator includes a movable body that moves along a drive shaft axis. The movable body includes an acting portion that is configured to push the swash plate with the pressure in a control pressure chamber. The swash plate includes a receiving portion that contacts and is pushed by the acting portion. The acting portion and the receiving portion contact each other at an acting position. A bottom dead center associated part for positioning the piston at a bottom dead center is defined on the swash plate. When the inclination angle is minimized, the acting position is located at a position closer to the bottom dead center associated part than the drive shaft axis.

1 . A variable displacement swash-plate compressor comprising:
 a housing having a swash plate chamber and a cylinder bore;   a drive shaft that is rotationally supported by the housing;   a swash plate that is supported in the swash plate chamber and is rotational by rotation of the drive shaft;   a link mechanism arranged between the drive shaft and the swash plate, wherein the link mechanism allows an inclination angle of the swash plate to be changed with respect to a direction perpendicular to a drive shaft axis of the drive shaft;   a piston reciprocally received in the cylinder bore;   a conversion mechanism that causes the piston to reciprocate in the cylinder bore by a stroke corresponding to the inclination angle of the swash plate through rotation of the swash plate;   an actuator configured to change the inclination angle; and   a control mechanism that controls the actuator, wherein   the link mechanism includes
 a lug member that is located in the swash plate chamber and is fixed to the drive shaft, and 
 a transmitting member that transmits rotation of the lug member to the swash plate, 
   the actuator includes
 the lug member, 
 a movable body that is configured to rotate integrally with the swash plate and to move along the drive shaft axis, thereby changing the inclination angle, and 
 a control pressure chamber that is defined by the lug member and the movable body and is configured such that pressure in the control pressure chamber is changed by the control mechanism to move the movable body, 
   the movable body includes an acting portion that is configured to push the swash plate with the pressure in the control pressure chamber,   the swash plate includes a receiving portion that contacts and is pushed by the acting portion,   the acting portion and the receiving portion contact each other at an acting position,   a bottom dead center associated part for positioning the piston at a bottom dead center is defined on the swash plate, and   when the inclination angle is minimized, the acting position is located at a position shifted closer to the bottom dead center associated part than the drive shaft axis.   
     
     
         2 . The variable displacement swash-plate compressor according to  claim 1 , wherein
 the transmitting member is located on the swash plate and is positioned on an opposite side of the drive shaft axis from the bottom dead center associated part,   the swash plate has a swash plate weight that is located at a position closer to the bottom dead center associated part than the drive shaft axis and protrudes toward the acting portion, and   the receiving portion is located on the swash plate weight.   
     
     
         3 . The variable displacement swash-plate compressor according to  claim 2 , wherein
 the movable body has a movable body weight that is located a position closer to the bottom dead center associated part than the drive shaft axis, and   the movable body weight functions as the acting portion.   
     
     
         4 . The variable displacement swash-plate compressor according to  claim 1 , wherein
 the acting position is a first acting position,   a second acting position is defined that constitutes a pair with the first acting position, wherein the first acting position and the second acting position are located on opposite sides of a bottom dead center plane, which includes the bottom dead center associated part and the drive shaft axis,   the acting portion is a first acting portion that contacts the receiving portion at the first acting position, and   a second acting portion is provided that contacts the receiving portion at the second acting position.   
     
     
         5 . The variable displacement swash-plate compressor according to  claim 1 , wherein the acting position is a single position. 
     
     
         6 . The variable displacement swash-plate compressor according to  claim 5 , wherein, in relation to a maximum load position, where reaction force acting from the piston is maximized on the swash plate, the acting position is located in an area between the bottom dead center associated part and a position on an opposite side of the drive shaft axis from the bottom dead center associated part. 
     
     
         7 . The variable displacement swash-plate compressor according to  claim 1 , wherein, when the inclination angle is increased, the acting position is moved in a direction from the bottom dead center associated part toward the drive shaft axis. 
     
     
         8 . The variable displacement swash-plate compressor according to  claim 1 , wherein
 the swash plate has a through hole, which slides on an outer circumference of the drive shaft in response to changes in the inclination angle, and   the swash plate is guided by the link mechanism and the through hole along the drive shaft axis and in a direction of the inclination angle, thereby changing the inclination angle.