Piston compressor

A piston compressor comprising:

• a housing including a cylinder block, a discharge chamber, a swash plate chamber, and a shaft hole, the cylinder block having a plurality of cylinder bores and a plurality of first communication passages in communication with the plurality of cylinder bores;
• a drive shaft rotatably supported in the shaft hole;
• a fixed swash plate configured to rotate in the swash plate chamber by rotation of the drive shaft and having a constant inclination angle with respect to a plane that is perpendicular to the drive shaft;
• a plurality of pistons, each of the pistons being accommodated in the corresponding cylinder bore, the piston forming a compression chamber in the cylinder bore and being coupled to the fixed swash plate;
• a discharge valve configured to discharge refrigerant from the compression chamber into the discharge chamber;
• a movable body disposed in the drive shaft and rotatable together with the drive shaft, the movable body being movable with respect to the drive shaft in a direction of an axis of the drive shaft according to a control pressure, the movable body having a second communication passage that intermittently communicates with each of the first communication passages by the rotation of the drive shaft, wherein a flow rate of the refrigerant discharged from the compression chamber into the discharge chamber changes according to a position of the movable body in the direction of the axis of the drive shaft;
• and
• a control valve configured to control the control pressure, wherein
• the drive shaft includes a main body that faces some of the first communication passages in communication with the corresponding compression chamber in a compression stroke or a discharge stroke,
• the movable body has a forming surface that is located opposite to the main body with respect to the axis and is exposed in the shaft hole,
• the first communication passages are connected to the second communication passage by the movable body, and
• the some of the first communication passages are disconnected from the second communication passage by the main body facing the some of the first communication passages.