Flow restricting structure in displacement controlling mechanism of variable displacement compressor

A variable displacement compressor for compressing refrigerant that is drawn into a suction pressure zone and discharging the refrigerant to a discharge pressure zone, the compressor comprising:

• a housing assembly, which has a control pressure chamber;
• a drive shaft, which is rotatably supported by the housing assembly;
• a plurality of cylinder bores formed in the housing assembly, wherein the cylinder bores are arranged about the drive shaft;
• a plurality of pistons, each of which is accommodated in one of the cylinder bores, wherein each piston defines a compression chamber inside the corresponding cylinder bore;
• a swash plate, which is tiltably accommodated in the control pressure chamber, wherein the swash plate reciprocates each piston inside the corresponding cylinder bore, and each piston compresses refrigerant that is drawn into the corresponding compression chamber from the suction pressure zone and discharges the refrigerant to the discharge pressure zone, and wherein the inclination angle of the swash plate is varied in accordance with the pressure in the control pressure chamber;
• a supply passage, which connects the control pressure chamber to the discharge pressure zone, wherein refrigerant in the discharge pressure zone flows to the control pressure chamber through the supply passage, wherein the housing assembly has a passage defining wall, which defines the supply passage;
• a pressure release passage, which connects the control pressure chamber to the suction pressure zone, wherein refrigerant in the control pressure chamber is released to the suction pressure zone through the pressure release passage, wherein the housing assembly has a passage defining wall, which defines the pressure release passage;
• and
• a shutter for closing one of the supply passage and the pressure release passage, wherein the shutter is fitted to the passage defining wall defining the corresponding passage, wherein the shutter is made of synthetic resin or rubber and includes a restricting passage.

A variable displacement compressor for compressing refrigerant that is drawn into a suction pressure zone and discharging the refrigerant to a discharge pressure zone, the compressor comprising:

• a housing assembly, which has a control pressure chamber;
• a drive shaft, which is rotatably supported by the housing assembly;
• a plurality of cylinder bores formed in the housing assembly, wherein the cylinder bores are arranged about the drive shaft;
• a plurality of pistons, each of which is accommodated in one of the cylinder bores, wherein each piston defines a compression chamber inside the corresponding cylinder bore;
• a swash plate, which is tiltably accommodated in the control pressure chamber, wherein the swash plate reciprocates each piston inside the corresponding cylinder bore, and each piston compresses refrigerant that is drawn into the corresponding compression chamber from the suction pressure zone and discharges the refrigerant to the discharge pressure zone, and wherein the inclination angle of the swash plate is varied in accordance with the pressure in the control pressure chamber;
• a supply passage, which connects the control pressure chamber to the discharge pressure zone, wherein refrigerant in the discharge pressure zone flows to the control pressure chamber through the supply passage;
• a pressure release passage, which connects the control pressure chamber to the suction pressure zone, wherein refrigerant in the control pressure chamber is released to the suction pressure zone through the pressure release passage, wherein at least one of the supply passage and the pressure release passage has an annular section that is defined by the circumferential surface of the drive shaft and the circumferential wall of the housing assembly that surrounds the drive shaft;
• and
• an annular shutter for closing the annular section, wherein the shutter is fitted between the circumferential surface of the drive shaft and the housing assembly, wherein the shutter is made of synthetic resin or rubber and includes a restricting passage.