Abstract: A refrigerant circuit includes a compressor and an expansion valve. The expansion valve is connected to a discharge muffler of the compressor by a high pressure conduit. The expansion valve is also connected to a suction passage of the compressor by a low pressure conduit. The high pressure conduit includes a condenser and the low pressure conduit includes an evaporator. A check valve is located between the discharge muffler and the high pressure conduit to selectively connect and disconnect the high pressure conduit with the discharge muffler. A relief valve is attached to the discharge muffler upstream of the check valve. If the pressure in the compressor is abnormally high when the check valve closes, the relief valve releases the abnormally high pressure from the discharge muffler. Therefore, if the check valve fails to function, the relief valve prevents the pressure in the compressor from being abnormally high.

Abstract: A compressor has a cam plate located in a crank chamber and mounted on a drive shaft and a piston coupled to the cam plate and located in a cylinder bore. The piston compresses gas supplied to the cylinder bore from a separate external circuit by way of a suction chamber and discharges the compressed gas to the external circuit by way of a discharge chamber. The cam plate is tiltable between a maximum inclined angle position and a minimum inclined angle position with respect to a plane perpendicular to an axis of the drive shaft according to a difference between the pressure in the crank chamber and the pressure in the cylinder bore. The piston moves by the stroke based on an inclination of the cam plate to control the displacement of the compressor. A valve is placed between the discharge chamber and the external circuit.

Abstract: An electromagnetic control valve is provided. The control stability of the electromagnetic control valve is improved because: (1) one end of the guide pin is forced into and then secured in a hole formed in the center of the coil guide so that the plunger moves in the center of the suction portion; (2) one end of the connecting rod is forced into and then secured in a hole formed in the center of the plunger, and a guide portion for guiding the connecting rod is provided in the center of the upper main body; or (3) the connecting rod is forced into and then secured in a hole formed in the center of the plunger, and a first guide portion for guiding the connecting rod is provided at the lower end of the coil guide and/or a second guide portion for guiding the connecting rod is provided at the lower end of the upper main body.

Abstract: A compressor has a refrigerant gas circulation passage selectively connected to and disconnected from an external refrigerant circuit. The compressor has a swash plate supported on a drive shaft for integral rotation with inclining motion with respect to the drive shaft which swash plate is coupled in driving relationship to a plurality of pistons which move reciprocatably within cylinder bores for compressing the gas. The swash plate is movable between a maximum inclined angle and a minimum inclined angle. A disconnecting valve disconnects the discharge chamber in the circulation passage from the external refrigerant circuit when the swash plate is at the minimum inclined angle. A bleed hole bleeds the refrigerant gas from the refrigerant circulation passage to the external refrigerant circuit to suppress rapid increase of the inclined angle when the disconnecting valve operates.

Abstract: A variable displacement refrigerant compressor has a tilting swash plate connected to a number of pistons. The pistons are located in a cylinder block. The cylinder has a front end surface that faces the swash plate. A central bore is formed in the cylinder block to hold a drive shaft, a radial bearing, and a movable spool, or shut-off member, which regulates gas flow within the compressor. An area of the front end of the cylinder block surrounding the central bore is located forward of the axial center of the bearing.

Abstract: A compressor has a drive plate located in a crank chamber and tiltably mounted on a drive shaft and a piston operably coupled to the drive plate and located in a cylinder bore. The inclination of the drive plate is variable according to a difference between the pressure in the crank chamber and the pressure in the cylinder bore. The compressor has an adjusting mechanism for adjusting the pressure in one of the crank chamber and a suction chamber to vary the difference between the pressure in the crank chamber and the pressure in the cylinder bore. The adjusting mechanism includes a gas passage for passing the gas used for adjusting the pressure and a control valve for adjusting the amount of the gas flowing in the gas passage. The control valve includes a valve body, a reacting member and a solenoid. The valve body adjusts the opening size of the gas passage. The reacting member moves the valve body in accordance with the pressure of the gas supplied to the compressor from the external circuit.

Abstract: A compressor housing and method of manufacture and assembly are disclosed. The compressor housing includes a cylinder block and a front housing. An annular projection is formed on the front end of the cylinder block. An annular groove is formed on the rear end of the front housing. The cylinder block and the front housing are secured to each other to prevent the front housing from being displaced in relation to the cylinder block by engaging the annular projection with the annular groove. A gasket is located between the front end of the cylinder block and the rear end of the front housing secured to each other to seal between the cylinder block and the front housing. This compressor and its method of manufacture reduce the amount of misalignment between a shaft bore in the cylinder block and a shaft bore in the front housing, which improves the performance of the compressor.

Abstract: A variable displacement type compressor is disclosed. The compressor includes a housing, a cylinder bore within the housing, a piston located in the cylinder bore, a drive shaft rotatably supported by the housing, a rotary support mounted on the drive shaft, and a cam plate connected to the piston. The cam plate is supported tiltably on the drive shaft and is slidable in axial directions of the drive shaft. The cam plate inclines between a maximum inclination position and a minimum inclination position when the displacement of the compressor is changed. A first moment is applied to the cam plate by a compression reaction force of the piston when the compressor is operating. A hinge mechanism is located between the rotary support and the cam plate. The cam plate is rotated integrally with the drive shaft, the rotary support, and the hinge mechanism.

Abstract: A variable displacement compressor includes a gas passage for connecting a discharge chamber with a crank chamber. The control valve is located in the gas passage to control the pressure in the crank chamber. The control valve has a valve hole and a valve chamber located in the gas passage. A valve body is located in the valve chamber to adjust the opening size of the valve hole. A solenoid has a plunger and a plunger chamber for accommodating the plunger. A rod is located between the plunger and the valve body to transmit the movement of the plunger to the valve body. When the solenoid is de-excited, the bottom end face of the plunger abuts against the inner bottom wall of the plunger chamber. A plurality of grooves are provided on the bottom end face of the plunger and extend radially. The grooves define recessed passages between the bottom end face of the plunger and the inner bottom wall of the plunger chamber to prevent the bottom end face from adhering to the inner bottom wall.

Abstract: A compressor has a control valve that adjusts the pressure difference between a crank chamber and a cylinder bore for controlling the inclination of a drive plate. The control valve protrudes outward from the compressor housing. The compressor also has a support protruding outward from the front housing and a leg protruding outward from the cylinder block. The outer ends of the support and the leg extend further from the compressor than the furthest extremity the control valve. Therefore, when the compressor is placed on a flat surface, the support and the leg prevent the control valve from contacting the surface. This protects the control valve from damage during transport and handling.

Abstract: A control valve used in a variable displacement compressor. A valve chamber port communicates with a valve chamber. A port is connected with the valve chamber by a valve hole. A valve body selectively opens and closes the valve hole for controlling flow of fluid between the ports. An actuator actuates the valve body. A coil bobbin is accommodated in the casing. A coil is wound about the bobbin. The bobbin contacts a first connector plate. A ground lead of the coil is connected to the first connector plate. A terminal is connected to a supply lead of the coil. A second connector plate is attached to a lid. The second connector plate faces the first connector plate. Flexible contacts are located between the first connector plate and the second connector plate to electrically connect the connector plates.

Abstract: A variable displacement type compressor having a piston accommodated in a cylinder bore, a swash plate accommodated in a crank chamber for reciprocating the piston and a drive shaft for tiltably and rotatably supporting the swash plate. The swash plate includes projections that extend toward a thrust bearing and have outer surfaces that contact the thrust bearing. A shaft hole within which the drive shaft is located between the projections. The shaft hole has an opening that opens adjacent to the projections. A recess is formed at the end of the shaft hole adjacent to the projections. A hardening method is performed on the wall of the through hole and on the outer surfaces of the projections to improve wear resistance. The hardening method prevents overheating of localized areas of the swash plate.

Abstract: A control valve in a compressor that adjusts the discharge displacement based on controlling of an inclination of a cam plate. The compressor includes a supply passage for connecting a discharge chamber with a crank chamber. The control valve is placed midway on the supply passage. The control valve has a valve body. The valve body moves in a first direction to open the supply passage and moves in the second direction to close the supply passage. A reacting member reacts to suction pressure. A first transmitting member is placed between the reacting member and the valve body. A solenoid is opposed to the reacting member with respect to the valve body. The solenoid urges the valve body in the second direction via a second transmitting member when the solenoid is excited. An urging device urges the valve body in the first direction, The first transmitting member connects the reacting member with the valve body to move the valve body toward or away from the reacting member.

Abstract: A compressor having a compression mechanism within a housing for compressing a refrigerant gas according to the rotation of a rotary shaft operatively connected to an external power source. A pulley is mounted on the rotary shaft and located on one side of the housing for transmitting power from the external power source to the shaft. A fan sends air to the outer surface of the housing by rotating with the pulley. Heat transferring fins are provided on the housing adjacent to the fan.

Abstract: A compressor having a cam plate disposed in a crank chamber and mounted on a drive shaft. The cam plate is tiltable between a maximum inclined angle position and a minimum inclined angle position with respect to a plane perpendicular to an axis of the drive shaft according to a differential pressure in the crank chamber and in a cylinder bore. The cam plate varies the stroke of a piston based on an inclination thereof to control the displacement of the compressor. A supply passage connects a discharge chamber with the crank chamber to deliver the gas from the discharge chamber to the crank chamber. The supply passage has an inlet that is open in the discharge chamber. A control valve is disposed midway on the supply passage. The control valve adjusts the amount of the gas introduced into the crank chamber from the discharge chamber through the supply passage to control the pressure in the crank chamber. A filter is disposed at the inlet of the supply passage to filter the oil.

Abstract: A variable displacement compressor which has a suction chamber, a discharge chamber, and a crank chamber. The displacement of the compressor is controlled by supplying refrigerant to the crank chamber from the discharge chamber via a pressurizing passage and releasing the gas into the suction chamber via a pressure releasing passage. An increase in the pressure in the crank chamber decreases the displacement, and a decrease in the pressure in the crank chamber increases the displacement. A displacement controlling structure of the compressor includes an electromagnetic valve which alters the size of an area of the pressurizing passage. A computer controls the electromagnetic valve in accordance with commands to alter the displacement. The computer enlarges the opened area of the pressurizing passage by controlling the electromagnetic valve in response to commands to reduce the displacement.

Abstract: A swash plate is arranged to tilt between a maximum inclining angle and a minimum inclining angle based on differential pressure between a crank chamber and a suction chamber. At least one single-headed piston, that is coupled to the swash plate, is disposed in an associated cylinder bore and reciprocates at a stroke according to the inclining angle of the swash plate to compress refrigerant gas introduced to the cylinder bore from an external refrigerant circuit via the suction chamber. A pressure supply passage connects a discharge chamber with the crank chamber to supply the refrigerant gas from the discharge chamber into the crank chamber so as to increase the pressure in the crank chamber and a flow passage which allows flow of the refrigerant gas from the crank chamber to the suction chamber. An introducing passage introduces the refrigerant gas with low temperature from the external refrigerant circuit to substantially equalize the pressures in the crank chamber and the suction chamber.

Abstract: A compressor includes a cylinder block having a cylinder bore, a first housing attached to a first end of the cylinder block, a second housing attached to a second end of the cylinder block, a crank chamber defined between the cylinder block and the first housing, a drive plate located in the crank chamber and mounted on a drive shaft, and a piston operably coupled to the drive plate and located in the cylinder bore. The drive plate is tiltable between a maximum inclination position and a minimum inclination position according to a difference between the pressure in the crank chamber and the pressure in the cylinder bore. The cylinder block has a shutter chamber opening to the first end and the second end. A shutter member is accommodated in the shutter chamber. The shutter member is movable between a first position and a second position in response to the inclination of the drive plate to selectively connect and disconnect an external circuit with an suction chamber.

Abstract: A housing has a crank chamber and a plurality of cylinder bores. The housing also has a discharge chamber and a suction chamber, which are communicatable with the cylinder bores. A drive shaft is supported in the housing, and pistons are accommodated in the respective cylinder bores. A swash plate is supported on the drive shaft in such a manner that its inclined angle can be altered, so that the undulation of the swash plate causes the pistons to reciprocate. When this compressor is running with the swash plate set upright, a controller activates an electromagnetic solenoid to supply a lubricating oil to a pressure chamber from an oil-supplying pump. This causes the spool to shift to temporarily hold the swash plate to an inclined position from the upright position.