Variable displacement compressors

A variable displacement compressor comprising:

• a driving unit provided within a crank chamber, the driving unit changing compressor output discharge capacity in accordance with pressure within the crank chamber,
• a control passage releasing compressed refrigerant from a discharge pressure area into the crank chamber,
• a control valve disposed within the control passage, the control valve opening and closing the control passage to control the pressure within the crank chamber,
• an oil separator disposed within the control passage at an upstream side of the control valve, the oil separator separating oil from the compressed refrigerant, and
• means for delivering the oil separated from the compressed refrigerant to the crank chamber regardless of whether the control valve has opened or closed the control passage, wherein the means for delivering oil branches from a portion of the control passage that extends between the oil separator and the control valve.

A variable displacement compressor comprising:

• a driving unit provided within a crank chamber, the driving unit changing compressor output discharge capacity in accordance with pressure within the crank chamber,
• a control passage releasing compressed refrigerant from a discharge pressure area into the crank chamber,
• a control valve disposed within the control passage, the control valve opening and closing the control passage to control the pressure within the crank chamber,
• an oil separator disposed within the control passage at an upstream side of the control valve, the oil separator separating oil from the compressed refrigerant, and
• means for delivering oil separated from the compressed refrigerant to the crank chamber regardless of whether the control valve has opened or closed the control passage when the compressor is operated at maximum capacity, wherein the means for delivering oil communicates with a portion of the control passage that extends between the oil separator and the control valve.

A compressor comprising:

• a drive shaft rotatably disposed within a crank chamber,
• a swash plate pivotably coupled to the drive shaft and rotating together with the drive shaft at an inclination angle with respect to a plane perpendicular to the drive shaft,
• a piston movably disposed within a cylinder bore, the piston being connected to a peripheral edge of the swash plate and being arranged to reciprocate within the cylinder bore so as to compress refrigerant in response to rotation of the swash plate within the crank chamber, wherein compressor output discharge capacity changes in accordance with pressure changes within the crank chamber,
• a control passage arranged and constructed to release compressed refrigerant from a discharge pressure area into the crank chamber,
• a control valve disposed within the control passage, the control valve opening and closing the control passage so as to control the pressure within the crank chamber, and
• a throttle passage defined by a clearance between the cylinder bore and the piston, the throttle passage delivering oil disposed within the compressed refrigerant to the crank chamber regardless of whether the control valve has opened or closed the control passage.

A variable displacement compressor comprising:

• a drive shaft rotatably disposed within a crank chamber,
• a swash plate pivotably coupled to the drive shaft and rotating together with the drive shaft at an inclination angle with respect to a plane perpendicular to the drive shaft,
• a piston movably disposed within a cylinder bore, the piston being connected to a peripheral edge of the swash plate and being arranged and constructed to reciprocate within the cylinder bore so as to compress refrigerant in response to rotation of the swash plate within the crank chamber, wherein compressor output discharge capacity changes in accordance with pressure changes within the crank chamber,
• a control passage arranged and constructed to release compressed refrigerant from a discharge pressure area into the crank chamber,
• a control valve disposed within the control passage, the control valve opening and closing the control passage so as to control the pressure within the crank chamber, and
• a clearance defined by a clearance between the cylinder bore and the piston, the clearance delivering being arranged and constructed to supply oil within the compressed refrigerant to the crank chamber regardless of whether the control valve has opened or closed the control passage.