Abstract: A piston type variable displacement compressor has a housing, a drive shaft, a first thrust regulating mechanism including a first thrust bearing and a second thrust regulating mechanism including a second thrust bearing. The drive shaft has a first end and a second end. The first end projects from the housing. The first thrust regulating mechanism regulates a drive shaft to move in the direction from the first end to the second end. The first thrust regulating mechanism allows the drive shaft to rotate. The first thrust bearing has a first radius. The second thrust regulating mechanism regulates the drive shaft to move in a direction from the second end to the first end. The second thrust regulating mechanism allows the drive shaft to rotate. The second thrust bearing has a second radius. The second radius is smaller than the first radius.

Abstract: A variable displacement piston type compressor has a housing, a drive shaft, a cam plate and a piston. The drive shaft is rotatably supported by the housing. The drive shaft has a first end and a second end. The first end of the drive shaft extends through the housing. The cylinder block is placed between the first end and the second end. The suction chamber and the discharge chamber are defined near the first end relative to the cylinder block. The crank chamber is defined near the second end relative to the cylinder block. The refrigerant in the crank chamber is bled into the suction pressure region through a bleed passage. Thereby, the inclination angle of the cam plate is controlled. The crank chamber and the suction chamber are connected with each other through the bleed passage. The bleed passage is formed outside of the drive shaft.

Abstract: A suction chamber and a discharge chamber are defined in a front housing member. A crank chamber is defined between a cylinder block and a rear housing member. A drive shaft passes through the suction chamber and extends from a front end of a housing. The drive shaft is supported by the housing. A shaft sealing assembly for sealing the drive shaft is located in the suction chamber. In the cylinder block and a valve plate, a bleed passage is formed for connecting the crank chamber with the suction chamber. The bleed passage is inclined downward toward the suction chamber. The outlet of the bleed passage is above the shaft sealing assembly. In the suction chamber, a reservoir, which stores lubricating oil supplied through the bleed passage, is surrounds a lower part of the shaft sealing assembly.

Abstract: A piston type variable displacement fluid machine includes a drive shaft and a cylinder bore. A piston reciprocates along a line of movement in the cylinder bore in accordance with the rotation of the drive shaft. The stroke of the piston is varied between the maximum stroke and the minimum stroke, which is greater than zero. The displacement of the fluid machine is changed in accordance with the stroke of the piston. A ring groove is formed on the outer circumferential surface of the piston. A piston ring is fitted in the ring groove and moves with respect to the piston in the line of movement of the piston. An allowable movement amount of the piston ring with respect to the piston is greater than or equal to the minimum stroke of the piston.

Abstract: A seal is provided between the housing assembly of a variable displacement compressor and a rotary shaft to seal inside the housing assembly. The seal is retained in a retaining chamber, which is separated from a suction chamber and a control pressure chamber. A refrigerant passage is connected to the retaining chamber to feed a refrigerant to the retaining chamber to cause the refrigerant to contact the seal. The refrigerant passage includes a path extending from outside the housing assembly to the suction chamber through the retaining chamber. A restriction ring having a restriction function guides the refrigerant from the control pressure chamber to the retaining chamber and releases an internal pressure of the control pressure chamber.

Abstract: A torque limiter to be operatively coupled to an engine is secured to the outer periphery of a driving shaft through screwing-engagement. The driving shaft and the torque limiter are screw-engaged and fixed to each other so that the torque limiter is pushed or urged against a seating face formed at the outer periphery of the driving shaft. The seating face abuts against the torque limiter restricting the screwing-movement of the driving shaft. Rotation force is transmitted between the driving shaft and the torque limiter via the seating face. A cylindrical member is disposed between the torque limiter and the seating face of the driving shaft. The cylindrical member is press-fitted and fixed to the outer periphery of the driving shaft, so that the power transmission between the driving shaft and the torque limiter is also performed through the press-fit portion between the cylindrical member and the driving shaft.

Abstract: A seal structure for use in a compressor has a first member, a second member, an O-ring and a gasket. The first member and the second member constitute a housing of the compressor. The first member and the second member are joined to each other at a joint. The O-ring and the gasket are interposed at the joint in a predetermined manner.

Abstract: A multi-stage compressor includes a first bore for a primary compression and a second bore for a secondary compression. A first piston is accommodated in the first bore and a second piston is accommodated in the second bore. A piston ring is attached to the first piston and a second piston ring is attached to the second piston. The inner diameters of the bores, the outer diameters of the pistons, and the outer diameters of the piston rings are equal to each other respectively. Thus, the bores are easily formed. Since only one type of piston and one type of piston ring are required to be manufactured, the manufacture of the above mentioned products is simplified. As a result, manufacture of the compressor becomes easy and the manufacturing cost is reduced.

Abstract: An apparatus controls a variable displacement compressor used in a refrigerant circuit. The compressor includes a drive shaft, which is rotated by an engine. When the drive shaft rotates, the compressor compresses refrigerant sent from the external refrigerant circuit and discharges the compressed refrigerant to an external refrigerant circuit. When the displacement of the compressor is minimized, the circulation of refrigerant in the refrigerant circuit is stopped. The apparatus has a control mechanism for varying the pressure in the crank chamber. A detector detects a physical quantity that reflects the heating status of the compressor. When the compressor displacement is minimized and the quantity detected by the detector indicates that the heating status of the compressor is deteriorating, a controller commands the control mechanism such that the displacement of the compressor is greater than the minimum displacement.

Abstract: A compressor has a high-pressure relief valve and a low-pressure relief valve. The high-pressure relief valve in use for a discharge region opens when the pressure of gas in the discharge region is more than a first predetermined pressure. The high-pressure relief valve is provided with a first shim. The low-pressure relief valve in use for a suction region opens when the pressure of gas in the suction region is more than a second predetermined pressure which is lower than the first predetermined pressure. The low-pressure relief valve is provided with a second shim. The high-pressure relief valve and the low-pressure relief valve have similar structure to each other.

Abstract: An improved scroll compressor having a movable scroll that orbits without being inclined. The compressor has a fixed scroll formed in the housing. The movable scroll is accommodated in the housing and mates with the fixed scroll. The movable scroll is driven by a drive shaft via a crank mechanism. A flange is formed at the periphery of the movable scroll and lies perpendicular to the drive shaft. A groove is formed in the housing. The groove is slightly wider than the thickness of the flange. The flange is slidably accommodated in the groove. Support holes extend in the housing. A pin is supported in each support hole. The ends of each pin are received in guide holes through the flange. Since engagement of the flange and the groove prevents the movable scroll from being inclined, the pin is maintained parallel to the guide holes and follows the wall of the guide holes. As a result, uneven wear of the pins and the guide holes is avoided.

Abstract: An air-conditioning system capable of always effectively performing the heating function by selectively using one of a cooling circuit and a heating circuit sharing a variable displacement type compressor is disclosed. An electromagnetic capacity control valve (43) controls the discharge capacity of a variable displacement type compressor (25) in response to the differential pressure between the discharge pressure Pd of a discharge chamber (132) and the suction pressure Ps of a suction chamber (131). The energization and deenergization of the capacity control valve (43) is controlled by a control unit (59). When a cooling command switch (63) is turned on, the control unit (59) deenergizes a switching valve (29) thereby to control the cooling operation while at the same time controlling the discharge capacity by the capacity control valve (43).

Abstract: A compressor includes a housing having a hollow projection portion, a rotary shaft provided rotatably within the housing, a piston reciprocating in accordance with rotation of the rotary shaft for sucking and discharging refrigerant, a bearing disposed within the projection portion of the housing for rotatably supporting one end of the rotary shaft and an attaching leg portion formed on an outer surface of the projection portion of the housing. The attaching leg portion is fastened to an engine block, a bracket or the like by using a bolt or the like.

Abstract: An electromagnetic actuator includes a cylinder, a stationary core and a movable core arranged in the cylinder, and a coil located about the cylinder. The movable core moves in the cylinder in accordance with an electromagnetic force, which is generated between the stationary core and the movable core based on the current supply to the coil. The cylinder includes a first cylindrical member made of nonmagnetic material, and a second cylindrical member made of magnetic material. The first cylindrical member surrounds the stationary core and the movable core. A part of the first cylindrical member in the vicinity of the movable core is made thin to form a small diameter portion. The small diameter portion is fitted to the second cylindrical member.

Abstract: A control valve for a variable displacement compressor is provided. A retainer cylinder in the control valve includes a first cylindrical member made of non-magnetic material and a second cylindrical member having a bottom portion made of magnetic material. A shim is intervened a bottom surface of a plunger and inner bottom surface of the second cylindrical member. The retainer cylinder has good magnetic permeability between a coil and the plunger, even though the wall of the cylinder thickens to improve the withstanding pressure to internal refrigerant pressure.

Abstract: A compressor has a front housing, a rear housing, a plurality of bolts, and a rigid plate. The rear housing is connected to the front housing. The bolts connect the front housing and the rear housing in an axial direction. The rigid plate is disposed between an axial end surface of one of the front and rear housings and heads of the bolts. The front housing and the rear housing are connected by the bolts via the rigid plate.

Abstract: A compressor has a housing and a cylinder block. The housing includes suction and discharge chambers. The cylinder block is fixed to the housing via a valve plate assembly. The valve plate assembly forms suction and discharge ports and suction and discharge valves. A partition wall is formed with the housing, and separates the suction chamber and the discharge chamber. The housing includes a first surface, and the cylinder block includes a second surface. At least one of the first and second surfaces is concave in shape. The cylinder block is screwed to the housing at the partition wall or a position closer to the central axis of the housing than the partition wall by a bolt so that the first surface faces the second surface.

Abstract: A first external refrigerant circuit includes a condenser, a pressure reducing device, and an evaporator. A compressor is directly connected to a drive source of the vehicle to permit power transmission and compresses a refrigerant by being driven by the drive source at all times. The compressor and the first external refrigerant circuit form a refrigerant circulation circuit. A second external refrigerant circuit connects a discharge chamber and a suction chamber of the compressor at the outside of the compressor and permits the circulation of a refrigerant that is not involved in air conditioning. Control devices selectively open or close the first external refrigerant circuit and the second external refrigerant circuit, respectively.

Abstract: A piston-operated compressor, of swash plate type and using CO2 as a refrigerant, having a casing member in which a cylinder bore is formed to have a cylindrical peripheral wall surface and a piston reciprocating for compression in the cylinder bore and being formed of an aluminum alloy. The outer peripheral surface of the piston is coated with a film of a fluororesin material, and a piston ring of an iron metal is fitted in the neighborhood of the top portion of the piston to permit the CO2 refrigerant to be compressed under high pressure. A first oil groove is formed in peripheral direction in parallel to and below the vicinity of the groove at the top portion of the piston in which the piston ring is fitted, and a second oil groove is formed below the first oil groove extending along the axial direction in parallel with the central axis of the piston.

Abstract: A controller for improving the durability of a compressor employed in a vehicle air conditioner without decreasing engine fuel efficiency. The controller detects the driving conditions of the vehicle and determines whether the engine is in a reversely driven state, in which the vehicle wheels drive the engine instead of the engine driving the wheels. The controller increases the amount of refrigerant discharged from the compressor when the engine is in the reversely driven state.