Abstract: A variable displacement compressor has a control valve for controlling the displacement of the compressor. When the pressure in a discharge chamber of the compressor (discharge pressure) is equal to or higher than a first threshold value, a controller executes a limiting control for limiting the discharge pressure. During the limiting control, the controller gradually decreases a duty ratio, which is sent to the control valve, such that the displacement of the compressor is gradually decreased. When the duty ratio is decreased to a reference duty ratio, the controller sets the duty ratio to zero %. As a result, the compressor displacement is minimized and the discharge pressure is lowered. Therefore, the pipes of an external refrigerant circuit does not receive excessive load based on high discharge pressure.

Abstract: A variable displacement compressor has a control valve for controlling the displacement of the compressor. When the pressure in a discharge chamber of the compressor (discharge pressure) is equal to or higher than a first threshold value, a controller executes a limiting control for limiting the discharge pressure. During the limiting control, the controller gradually decreases a duty ratio, which is sent to the control valve, such that the displacement of the compressor is gradually decreased. When the duty ratio is decreased to a reference duty ratio, the controller sets the duty ratio to zero %. As a result, the compressor displacement is minimized and the discharge pressure is lowered. Therefore, the pipes of an external refrigerant circuit does not receive excessive load based on high discharge pressure.

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 sealing structure for the shaft of a compressor. The sealing apparatus includes an inner ring, and outer ring, and a support ring. The inner ring and the outer rings have flexible annular lips that contact the surface of the rotary shaft. The support ring supports the inner lip and determines the position of the inner lip. The first lip permits fluid leakage along the surface of the shaft, while the second lip forms a fluid-tight seal with the shaft. The support ring prevents the internal pressure of the compressor from pressing the first lip against the shaft with excessive force, which extends the life of the sealing apparatus.

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 for adjusting the amount of the gas introduced into the crank chamber from the discharge chamber. The control valve has a valve hole and a valve chamber respectively disposed midway on the supply passage. A valve body is located in the valve chamber to adjust the opening size of the valve hole. A reacting member reacts to the pressure in the first area. The reacting member moves the valve body via a first rod in accordance with the pressure in the first area. A solenoid is opposed to the reacting member with respect to the valve body. The solenoid has a fixed core, a plunger and a plunger chamber.

Abstract: A compressor has a swash (slanting-cam) plate located 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 a drive shaft according to a difference between the pressures in the crank chamber and a cylinder bore. The cam plate varies the stroke of a piston in the cylinder bore based on an inclination thereof to control the displacement of the compressor. A shutter member is movable between a first position where the shutter member connects a external circuit with a suction chamber and a second position where the shutter member disconnects the external circuit with the suction chamber in response to the inclination of the cam plate. The cam plate moves the shutter member to the second position when the cam plate is at the minimum inclined angle position to minimize the displacement of the compressor.

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 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.

Abstract: An electromagnetic valve (32) opens and closes a pressurizing passage (31). When the pressurizing passage (31) is opened, a swash plate (15) mounted on a rotary shaft (9) inclines toward the minimum inclination. As the swash plate (15) inclines toward the minimum inclination, the swash plate (15) counteracts the spring force of a suction passage opening spring (24) and pushes a transmitting cylinder (28) and a shutter (21). The shutter (21) abuts against a positioning surface (27) when the swash plate inclination corresponds to a minimum inclination and disconnects a suction passage (26) from a suction chamber (3a). The disconnection impedes refrigerant circulation in the external refrigerant circuit (35). A refrigerant circulation controlling circuit (42) energizes the electromagnetic valve (32) and opens the pressurizing passage (31) for a certain time period starting from when a drive electric source (14) is activated.

Abstract: A compressor has a refrigerant gas passage selectively connected to and disconnected from a refrigerant circuit apart from the compressor. A swash plate is supported on a drive shaft for integral rotation with inclining motion with respect to the drive shaft to drive the pistons. The swash plate is moveable between a maximum inclined angle and a minimum inclining angle. A disconnecting member disconnects the refrigerant circuit from the refrigerant gas passage when the swash plate is at the minimum inclined angle.

Abstract: A compressor has a housing body, a drive shaft, a swash plate, and a piston. The swash plate converts rotation of the drive shaft to reciprocating movement of the piston in a cylinder bore. The piston compresses gas supplied to the cylinder bore from an external circuit via a suction chamber and discharges the compressed gas to a discharge chamber. The swash plate is tiltable with respect to a plane perpendicular to the longitudinal axis of the drive shaft according to differential pressure between the crank chamber and the suction chamber. The swash plate controls the displacement of the compressor based on the inclination thereof. A spool is movable longitudinally between a first position and a second position in response to the inclination of the swash plate. The spool connects the external circuit with the suction chamber in the first position and disconnects the external circuit from the suction chamber in the second position. The housing body has a surface slidably engaged by the spool.

Abstract: A compressor has a swash plate tiltable between a maximum and minimum inclining angles with respect to an axis of the drive shaft according to a difference between pressures in a crank chamber and a suction chamber. An electromagnetic valve is disposed in a pressure passage, and opens or closes the pressure passage according to instruction of an external computer. This instruction is based on an operation status of the compressor so that the electromagnetic valve adjusts the pressure in the crank chamber. The pressure passage connects the crank chamber and the suction chamber. The swash plate is inclined toward the maximum inclining angle when the pressure passage is open to release the pressure in the crank chamber to the suction chamber. The swash plate is inclined toward the minimum inclining angle when the pressure passage is closed to increase the pressure in the crank chamber.

Abstract: Disclosed is a compressor having a drive shaft in a crank chamber and a swash plate supported on the drive shaft for integral rotation therewith to drive a piston in a cylinder bore. The piston compresses gas sucked from a suction chamber into the cylinder bore and discharges the compressed gas to a discharge chamber and the amount of the discharged gas is variable between a minimum and maximum values based on variation of the inclined angle of the swash plate between a minimum and maximum values.

Abstract: A variable displacement compressor having a rotary shaft and a swash plate is described. The swash plate is mounted on the shaft and rotates integrally with the shaft. The swash plate tilts between a maximum inclined angle and a minimum inclined angle and is connected to a plurality of pistons. The inclined angle of the swash plate is altered by the difference between the pressure in a crank chamber and the pressure in a suction chamber. Each piston reciprocates inside a cylinder bore with a stroke determined by the inclined angle of the swash plate and compresses refrigerant gas, which includes oil mist. A spool is arranged adjacent to the swash plate on the shaft. On the shaft, a thrust bearing is provided between the swash plate and the spool, and a radial bearing is provided in the spool. The spool has an opening opposed to the swash plate. Grooves that allow the flow of refrigerant gas into the spool are formed at the opening in the walls of the spool.

Abstract: A compressor having an internal refrigerant gas passage selectively connected to and disconnected from an external refrigerant circuit separately provided from the compressor is described. The compressor has a plurality of pistons reciprocable in a plurality of cylinder bores in a housing for compressing gas supplied from the external refrigerant circuit to the internal refrigerant gas passage. A drive shaft is rotatably supported by the housing. A swash plate is supported on the drive shaft for integral rotation with inclining motion with respect to the drive shaft. The swash plate is movable between a maximum inclined angle and a minimum inclined angle. The disconnecting device disconnects the internal refrigerant gas passage from the external refrigerant circuit when the swash plate is at the minimum inclined angle. The internal refrigerant gas passage includes a first passage which connects a crank chamber and a suction chamber to deliver the refrigerant gas from the crank chamber to the suction chamber.

Abstract: A compressor includes a rotary drive shaft having a first end and a second end, both the ends being rotatably supported by opposing walls of a crank chamber defined in a casing and a swash plate tiltably mounted on the drive shaft and operably coupled with a piston in a cylinder bore. A rotation of the drive shaft results in a reciprocating movement of the piston for compressing refrigerant gas in a cylinder bore. A rotary member is secured to the first end which extends outside the casing. the rotary member supplies a power to the drive shaft from a power supply. A support member, disposed between the rotary member and the first end, protrudes outward from the casing. A first bearing, disposed between the support member and the rotary member, receives a thrust load and a radial load acting on the rotary member when the rotary member rotates. A second bearing, disposed between the casing and the second end, receives the radial load acting on the rotary member when the rotary member rotates.

Abstract: A swash plate type compressor is connected with an external refrigerant gas circuit. A device accommodated in the compressor disconnects the external circuit with the suction chamber when the swash plate is at the minimum inclining angle. A pressure decreasing passage creates the connection between the crank chamber and the suction chamber to decrease the pressure in the crank chamber. This passage releases the pressure in the crank chamber to the suction chamber when the pressure in the crank chamber is greater than the pressure in the suction chamber so that the swash plate is inclined toward the maximum inclining angle. An adjusting device adjusts the pressure in the pressure decreasing passage so that the pressure decreasing passage is opened to a greater degree when the swash plate is at the maximum inclining angle than when the swash plate is between the maximum and minimum inclining angles.

Abstract: A compressor has a refrigerant gas passage selectively connected to and disconnected from a refrigerant circuit separately provided from the compressor. The compressor has a plurality of pistons reciprocable in a housing for compressing refrigerant gas. A drive shaft is rotatably supported by the housing. A swash plate is supported on the drive shaft for integral rotation with inclining motion with respect to the drive shaft to drive the pistons. The swash plate is movable between a maximum inclined angle and a minimum inclined angle. A disconnecting member disconnects the refrigerant circuit from the refrigerant gas passage when the swash plate is at the minimum inclined angle. A bleed hole bleeds the refrigerant gas from the refrigerant gas passage to the refrigerant circuit to suppress rapid increase of the inclined angle when the disconnecting member operates.

Abstract: In a housing 1, 2, a rotor 11 is secured to a drive shaft 6 and a sleeve 12 is supported movably. A rotary swash plate 14 is tiltably supported on the sleeve 12 and is coupled to the rotor 11. Coupled to the rotary swash plate 14 are pistons 8 which move in the respective bores 9. A fluid is supplied to each bore 9 from a suction chamber 20, and a fluid compressed by each piston 8 is discharged to a discharge chamber 21. A control valve 25 controls the difference between the pressure in the suction chamber 20 and the pressure in a crank chamber 5 to change the inclination angle of the rotary swash plate 14, so that the discharge displacement of a compressor becomes variable. In the housing 1, a spool 32 is movably provided while enclosing the drive shaft 6.