Variable Capacity Compressor

Abstract

A variable capacity compressor including swash plate connected to rotor via link mechanism can calculate a moment of rotational motion acting on swash plate and set the total moment of rotational motion in inclination angle increasing direction acting on swash plate at minimum inclination angle to a small value. The shape or the like of swash plate 111 or the like are set so that moment M RX +M S becomes a moment which orients swash plate in inclination angle increasing direction in a range from θmin (0°) to θb and becomes a moment which orients swash plate in inclination angle decreasing direction in a range from an inclination angle exceeding θb to θmax. The moment acting in inclination angle increasing direction of swash plate by setting the shape or the like of link arm 121 or the like is determined by calculating the sum of moment components.

1 . A variable capacity compressor which variably controls a discharge capacity of refrigerant by connecting a rotor fixed to a drive shaft rotatably supported within a housing to a swash plate slidably attached to the drive shaft so that an inclination angle relative to an axis line of the drive shaft is variable via a link arm with both ends rotatably connected to the rotor and the swash plate, allowing tilting of the swash plate while causing the swash plate to rotate synchronously with the rotor, converting the rotation of the swash plate to reciprocating motion parallel to the drive shaft of a piston inserted into a cylinder bore to draw and discharge the refrigerant, and controlling the inclination angle of the swash plate to control a stroke amount of the piston, wherein:
 a shape, weight, and center of gravity of the swash plate, or those of the swash plate and a connected body integral therewith, are set so that a moment of rotational motion caused by the swash plate, or the swash plate and the connected body integral therewith, when the drive shaft rotates in the position of a minimum inclination angle θmin of the swash plate acts in an inclination angle decreasing direction of the swash plate;   a shape, weight, and center of gravity of the link arm, or those of the link arm and a connected body integral therewith, are set so that a total moment of rotational motion caused by the link arm, the swash plate, and the connected body integral therewith acts in an inclination angle increasing direction of the swash plate; and   the moment of rotational motion acting in the inclination angle increasing direction of the swash plate by setting the shape, weight, and center of gravity of the link arm, or those of the link arm and the connected body integral therewith, is determined by calculating a sum of moment components about the center of gravity and moment components caused by a centrifugal force acting on the center of gravity.   
     
     
         2 . The variable capacity compressor according to  claim 1 , wherein a minimum inclination angle θmin of the swash plate is set to 0° supposing that the inclination angle of the swash plate is 0° when the swash plate is orthogonal to the axis line of the drive shaft, and the moment of rotational motion caused by the link arm, the swash plate, and the connected body integral therewith acts in the inclination angle increasing direction of the swash plate in a range from the minimum inclination angle θmin to a predetermined inclination angle θb and acts in the inclination angle decreasing direction of the swash plate in a range from an inclination angle just exceeding the predetermined inclination angle θb to a maximum inclination angle θmax, and the predetermined inclination angle θb is set to a minimum inclination angle range where a compression reaction force is applied when the piston compresses the refrigerant.