Abstract: A hydraulic drive system for a construction machine comprising a hydraulic pump (1) of variable displacement type, a pump regulator (2) for controlling a delivery rate of the hydraulic pump, a plurality of hydraulic actuators (7) driven by a hydraulic fluid supplied from the hydraulic pump, a plurality of directional control valves (4A-4D) for controlling respective flows of the hydraulic fluid supplied from the hydraulic pump to the plural hydraulic actuators, a low-pressure circuit (22), a center bypass line (23) for connecting in series center bypasses of the plural directional control valves (4A-4D) to the low-pressure circuit (22), a plurality of bleeding-off restrictors (26) in the center bypass line and having their openings variable in accordance with respectively associated directional control valves, a fixed restrictor (5) disposed in the center bypass line for producing a control pressure (PZ), and a pressure sensor (8) for detecting the control pressure and outputting a corresponding electric sign

Abstract: A variable capacity swash plate type refrigerant compressor having a swash plate assembly rotatably mounted on a drive shaft and capable of turning around a hinge-ball to change an angle of inclination thereof, and a plurality of pistons reciprocated by the swash plate assembly within a plurality of cylinder bores to implement suction, compression and discharge of refrigerant gas in response to the rotation of the drive shaft, the hinge-ball being formed with a central bore for permitting the drive shaft to extend therethrough, a single spherical outer face, and a pair of flat faces arranged symmetrically with respect to a plane passing the middle of the spherical outer face and perpendicular to the axis of the central bore.

Abstract: A compact and light flow dividing pump is disclosed. The pump includes a housing having an end plate attached to one end thereof. The end plate has a fluid suction port and a pair of fluid discharge ports. A pump mechanism is provided in the housing for receiving fluid through the suction port and discharging the received fluid through the discharge ports. A plurality of discharge passages are formed in the end plate between the pump mechanism and the discharge ports. A control valve is also provided in the end plate to control the flow rate of fluid in the discharge passages.

Abstract: A slant plate type compressor having a capacity or displacement adjusting mechanism includes a housing for a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a slant plate having a surface with an adjustable incline angle. The incline angle of the slant plate, and thus the capacity of the compressor, is controlled according to the pressure differential between the crank chamber and the suction chamber. The pressure in the suction chamber is controlled by a valve control mechanism which is disposed in a passageway linking the crank chamber and the suction chamber. An internally controlled safety valve device prevents an abnormal pressure differential between the crank and suction chambers.

Abstract: A multi-chamber fluid working machine has at least one electromagnetically controlled poppet valve linking each working chamber with respective high and low pressure fluid manifolds whereby displacement control is achieved by real time control of the electrically selectable poppet valves. Each valve seals via annular parts on the valve and its seat and is moved by reaction between a solenoid coil and a ferromagnetic part on the valve stem.

Abstract: A swash plate type compressor with a variable displacement mechanism is disclosed. The compressor includes a compressor housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism. The drive mechanism includes a drive shaft rotatably supported by the compressor housing, a pair of rotor plates fixed on the drive shaft and a swash plate having a surface with an adjustable incline angle or tilt. The rotor plates are arranged on opposite sides of the swash plate. The swash plate converts the rotating motion of the drive shaft into the reciprocating motion of the pistons which are coupled to the swash plate through bearings. A pair of hinge coupling mechanisms hingedly connect an arm portion of the swash plate to an arm portion of each of the rotor plates to permit variations in the incline angle or tilt of the swash plate.

Abstract: A slant plate type refrigerant compressor, such as a wobble plate type refrigerant compressor, with a capacity or displacement adjusting mechanism is disclosed. The capacity adjusting mechanism includes a valve device having an expandable/contractable bellows responsive to crank chamber pressure and a valve element fixedly attached to one end of the bellows to directly control the closing and opening of a passageway which connects a crank chamber and suction chamber. The bellows has a first effective pressure receiving cross-sectional area responsive to crank chamber pressure. The valve element has a second effective pressure receiving cross-sectional area responsive to suction chamber pressure.

Abstract: A variable capacity type slant plate compressor including a crank chamber a suction chamber and a discharge chamber is disclosed. The crank chamber is linked by a first communication path to the suction chamber, and is linked by a second communication path to the discharge chamber. A first valve control mechanism is disposed within the first communication path. A second valve control mechanism is disposed within the second communication path. The first valve control mechanism controls the opening and closing of the first communication path so that the suction chamber pressure is maintained at a predetermined constant value. The second communication path is compulsorily opened by operation of the second valve control mechanism in response to an external signal so as to compulsorily minimize the capacity of the compressor.

Abstract: A variable capacity single headed piston, swash plate type compressor provided with a rotation-to-reciprocation conversion mechanism having a swash plate rotated by a drive shaft and formed with annularly extended engaged portions on opposite faces thereof, a pair of shoes located between the swash plate and each of the single headed pistons, each shoe having formed therein an engaging portion circumferentially slidably engaged with one of the annular engaged portions of the swash plate, and a spherical face to be in a displaceable and turnable contact with a cylindrical support wall of a radial recess of each piston and permitting a passage of the swash plate during the rotation thereof. The engagement and contact of the shoes with the swash plate and the pistons provide the respective pistons with an accurate and stable axial support, to thereby prevent a local abrasion of the single headed pistons.

Abstract: A pumping mechanism featuring integration of a fixed-displacement radial ton pump within an electric drive motor and cooperative operation of a radially inwardly facing piston-actuating cam with a pair of opposing axially inwardly facing spool-valve actuating cams. The piston-actuating cam is effectively the inner surface of the rotating motor rotor, the pistons extending radially from a fixed central body. Consequent benefits of the integrated configuration are greater quietness, compactness, efficiency and corrosion resistance. The external motor unit provides protection, there is a damping effect, and there are fewer parts which are subject to damage or malfunction. Further reductions in noise and leakage are gained by synchronized operation, in terms of fluid pumping, of the spool-valve actuating cams and the piston-actuating cam.

Abstract: A variable capacity wobble plate compressor including a cylinder block, the cylinder block having a plurality of cylinders formed therein and a bearing-receiving hole formed therethrough, bearings received within the bearing-receiving hole, a discharging space defined on one side of the cylinder block, a crankcase defined on the other side of the cylinder block, a wobble plate accommodated within the crankcase and mounted on a drive shaft, a plurality of outlet ports communicating between respective ones of the cylinders and the discharging space, discharge valve means having a plurality of valve elements for closing and opening respective ones of the outlet ports, and a fixing member securing the discharge valve means to the cylinder block at the one side thereof, wherein the fixing member has a high pressure-introducing passage formed therethrough for introducing high-pressure refrigerant gas within the discharging space to the bearing-receiving hole, and then into the crankcase.

Abstract: A slant plate type compressor including a compressor housing having a cylinder block is disclosed. A plurality of cylinders are formed around the periphery of the cylinder block and a piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism. A crank chamber is formed between the cylinder block and a front end plate of the compressor housing. The drive mechanism includes a drive shaft rotatably supported in the compressor housing, a rotor coupled to the drive shaft and rotatable therewith, and a coupling mechanism for drivingly coupling the rotor to the pistons such that they rotary motion of the rotor is converted into reciprocating motion of the pistons. The coupling mechanism includes a plate having a surface disposed at a slant angle relative to the drive shaft. The slant angle changes in response to a change in pressure in the crank chamber to change the capacity of the compressor.

Abstract: A refrigerating system including a refrigerant circuit having a condenser, evaporator and wobble plate type compressor with a variable displacement mechanism. Two passages communicate between the crank chamber and the suction chamber in the cylinder block. A bellows is disposed in a first passage and controls the communication between the crank chamber and the suction chamber response to crank chamber pressure. A control valve is disposed in the second passage and controls communication between the crank chamber and the suction chamber in the second passage in response to a signal generated outside of the compressor. A control circuit controls the generation of the signal in response to thermodynamic characteristics related to the evaporator. The signal activates or deactivates the second control valve when the characteristic indicates a value beyond a predetermined range of values.

Abstract: A slant plate type compressor having a capacity or displacement adjusting mechanism includes a housing for a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a slant plate having a surface with an adjustable incline angle. The incline angle of the slant plate, and thus the capacity of the compressor, is controlled according to the pressure differential between the crank chamber and the suction chamber. The pressure in either the crank chamber or the suction chamber is controlled by an externally controlled valve mechanism which is disposed in a passageway linking the crank chamber and the suction chamber. An internally controlled safety valve device prevents an abnormal pressure differential between the crank and suction chambers.

Abstract: A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a slant plate having a surface with an adjustable incline angle. The incline angle is controlled according to the pressure in the crank chamber. The pressure in the crank chamber is controlled by a control mechanism which comprises a passageway linking the crank chamber and the suction chamber, and a valve device which controls the closing and opening of the passageway.

Abstract: A variable capacity wobble plate type compressor with a variable angle non-rotary wobble plate, having a suction chamber for refrigerant gas before compression, a discharge chamber for a refrigerant gas after compression, a crankcase defining a crank chamber to receive therein a drive and a wobble plate mechanism mounted about a drive shaft connectable to a drive source, i.e.

Abstract: A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a slant plate having a surface with an adjustable incline angle. The incline angle is controlled according to the pressure in the crank chamber. The pressure in the crank chamber is controlled by a control mechanism which comprises a first passageway linking the crank chamber and the suction chamber, and a valve device which controls the closing and opening of the first passageway.

Abstract: A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a member having a surface with an adjustable incline angle. The incline angle is controlled by the pressure in the crank chamber. The pressure in crank chamber is controlled by control mechanism which comprises a passageway communicating between the crank chamber and a suction chamber, a first valve device to control the closing and opening of the passageway and a second valve device to control pressure in an actuating chamber. The first valve device includes a bellows valve element and a valve shifting element.

Abstract: A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a member having a surface with an adjustable incline angle. The incline angle is controlled by the relative pressure between the crank and suction chambers. The relative pressure is controlled by a control mechanism which comprises a passageway communicating between the crank chamber and a suction chamber, a first valve device to control the closing and opening of the passageway and a second valve device to control the pressure in an actuating chamber. The first valve device includes a bellows and a valve shifting element coupled to the bellows.

Abstract: A rotary hydraulic machine which includes a housing having a shaft mounted for rotation within the housing about a shaft axis. A cylidner block is coupled to the shaft for co-rotation with the shaft within the housing and includes a plurality of cylinders disposed in a circumferential array parallel to and surrounding the shaft axis. A piston is disposed to reciprocate within each of the cylinders and is coupled to a yoke for determining displacement of the pistons within the cylinders. A valve plate is mounted on a valve block and includes kidney-shaped slots for registering with the cylinders as the cylinder block rotates, and thereby connecting the cylinders to pump input and output ports. A microprocessor-based controller is externally mounted on the pump valve block and includes internal memory having various remotely-selectable control programs prestored therein.

Abstract: The bellows in the stroke control valve of a variable stroke axial piston wobble plate refrigerant compressor is partially filled with an anti-freeze solution and continuously exposed to both suction pressure and crankcase pressure. This has the effect of reducing the piston stroke at high compressor speeds while increasing suction pressure to maintain some air conditioning performance.

Abstract: A slant plate type compressor including a crank chamber and a suction chamber is disclosed. The slant plate is disposed in the crank chamber at a variable slant angle. The slant angle varies in dependence on the crank chamber pressure. The crank chamber is linked by a communication path to the suction chamber. The slant angle may be varied by controlling the link of the crank and suction chambers to thereby vary the capacity of the compressor. The link of the crank and suction chambers through the communicaton path is controlled by a valve mechanism. The valve mechanism includes a first valve control device which opens or closes the communication path in response to an external signal to vary the compressor capacity, and a second valve control device which is responsive to the suction pressure to open or close the communication path.

Abstract: A wobble plate type compressor with a variable capacity mechanism is disclosed. Changing the displacement of a cylinders and therefore the capacity of the compressor is accomplished by varying the angle of an inclined surface of the wobble plate. This angle is varied by changing the difference in pressure between the crank chamber and the suction chamber. This pressure difference is controlled by changing the suction chamber pressure while uniformly maintaining the crank chamber pressure. In one embodiment the capacity varying mechanism includes a bellows. In another embodiment the capacity varying mechanism includes an electromagnetic valve and an electronic pressure sensor.

Abstract: A slant plate type compressor including a crank chamber and a suction chamber is disclosed. The slant plate is disposed in the crank chamber at a variable slant angle. The slant angle varies in dependence on the crank chamber pressure. The crank chamber is linked by a communication path to the suction chamber. The slant angle may be varied by controlling the link of the crank and suction chambers to thereby vary the capacity of the compressor. The link of the crank and suction chambers through the communication path is controlled by a valve mechanism. The valve mechanism includes a first valve control device which opens or closes the communication path in response to an external signal to vary the compressor capacity, and a second valve control device which is responsive to the suction pressure to open or close the communication path.

Abstract: In order to eliminate leakage and provide a more efficient system, a variable displacement hydraulic apparatus (10) includes a cylinder block (12) having a plurality of hydraulic cylinders (14) therein. Each of the cylinders (14) has a hydraulic piston (16) disposed therein for reciprocating movement relative thereto. The cylinders (14) and pistons (16) are disposed about an axis (18) of the hydraulic apparatus (10). The hydraulic apparatus (10) also includes a shaft (20) operatively associated with the pistons (16) for relative driven movement therebetween and a valve block (22) having a hydraulic fluid inlet port (24) for supplying hydraulic fluid to the cylinders (14) together with a hydraulic fluid outlet port (26) for returning hydraulic fluid from the cylinders (14). The inlet and outlet ports (24 and 26) communicate with the cylinders (14) through a port plate (28) having at least one port slot (30) therethrough.

Abstract: Hydraulic pump with axial pistons (1) in which each piston (1) forces the hydraulic liquid through a nonreturn valve, said nonreturn valves being connected to a control jack (20) by means of which the nonreturn valves can be made inactive, characterized by the fact that the nonreturn valves are placed in a chamber (10) and consist of a sliding support (15) inside of which there is disposed a spring (17) acting on an organ (16) serving as valve, which slides inside the sliding support (15), the latter being able, at will, to be coupled by any suitable means to the control jack (20).

Abstract: A refrigerating system including a refrigerant circuit having a condenser, evaporator and wobble plate type compressor with a variable displacement mechanism. Two passages communicate between the crank chamber and the suction chamber in the cylinder block. A bellows is disposed in a first passage and controls the communication between the crank chamber and the suction chamber response to crank chamber pressure. A control valve is disposed in the second passage and controls communication between the crank chamber and the suction chamber in the second passage in response to a signal generated outside of the compressor. A control circuit controls the generation of the signal in response to thermodynamic characteristics related to the evaporator. The signal activates or deactivates the second control valve when the characteristic indicates a value beyond a predetermined range of values.

Abstract: A variable capacity type swash plate compressor has a shaft, a swash plate, pistons functionally connected with the swash plate, and a detector for detecting the reciprocating stroke of the piston. The reciprocating stroke of the piston is varied in accordance with an inclining angle of the swash plate in such a manner that a top dead point of the piston at a working chamber defined at one end of the piston is substantially constant. The detector detects the change of the width of the reciprocating stroke of the piston and calculating the capacity of the compressor. The detector employs a plurality of magnets provided on a center portion of the piston and an electromagnetic sensor provided on a cylinder block for facing to the magnets.

Abstract: A swash plate type compressor having a pair of axially combined front and rear cylinder blocks forming therein a plurality of cylinder bores, a swash plate chamber, and an oil chamber in which a lubricating oil is stored to be stirred by a swash plate rotatably received in the swash plate chamber, a drive shaft centrally rotatably mounted in the combined cylinder blocks to cause a rotation of the swash plate, a plurality of reciprocatory double-headed pistons slidably fitted in the cylinder bores and operatively engaged with the swash plate via shoe members to be reciprocated by the rotation of the swash plate, a pair of thrust bearings axially supporting the swash plate, front and rear housings having suction chambers for the refrigerant gas before compression and discharge chambers for the refrigerant gas after compression, the front housing further having a shaft sealing chamber formed therein and separated from the suction chamber thereof to define an intermediate pressure chamber between the high pressur

Abstract: Reversible, variable displacement, hydraulic devices are useful in transmitting power from an engine to a driven device. The hydraulic components of such devices are generally quite bulky and difficulty to center to swash plate thereof. The subject device includes a pair of servo valves adjustably disposed within a case for individually controlling the flow of actuating fluid to and from a pair of hydraulic servo actuators. A servo feedback mechanism is provided to mechanically move a valve spool of one of the servo valves to a position for exhausting fluid from one of the servo actuators as the spool of the other servo valve is moved to a position for directing actuating fluid to the other of the servo actuators. The feedback mechanism also moves the spools substantially to their neutral position when a swash plate controlled by the servo actuators reaches a desired angular position after the other spool is first moved to the position for directing actuating fluid to the other servo actuator.

Abstract: A compressor of a movable slanting plate type which includes a shaft to be rotated by receiving an external driving force, a rotor having a plurality of cylinder chambers disposed in a parallel relation with the shaft so as to be rotated together with the shaft, a plurality of pistons which revolve while reciprocating within each of the cylinder chambers, a plurality of rods each connected at its one end, to each of the pistons, and having a ball joint at its other end, a plurality of holder shoes each connected to the rod through the ball joint for free directivity, a movable slanting plate revolving supporting said holder shoes, and capable of changing its inclination angle to one direction with respect in the shaft, a valve plate provided with a plurality of suction ports and discharge ports communicated with the cylinder chambers of the rotor, and a guide plate fixed to the shaft or the rotor and formed with guide bores for slidably guiding the plurality of the rods in the axial direction.

Abstract: In a control cylinder device of a variable displacement compressor, an annular cylinder concentric with a driving rotary shaft is provided in a housing of a compressor body, and an annular control piston is slidably fitted in the cylinder to define a control pressure chamber within the cylinder. The annular control piston is connected to a sleeve, such that the sliding movement of the sleeve can be controlled by the operation of the control piston. Further, inner and outer seal rings are interposed in an axially misaligned relation to each other between inner and outer slide surfaces of the cylinder and control piston. This facilitates an accurate formation of the inner and outer surfaces of the cylinder in the cylinder device on which the control piston slides. Also, this easily insures sealing properties required between the slide surfaces of the cylinder and the piston. In addition, it is possible to effectively prevent the inclination of the control piston within the cylinder.

Abstract: A driving rotary shaft is rotatably carried on a compressor body of a variable displacement compressor. On axial one side of a sleeve slidably carried on the driving rotary shaft, there is disposed a first spring of a displacement setting device for biasing the sleeve in one axial direction and holding a stopper, with which the sleeve is engageable, at a stop position on the driving rotary shaft. On the axial other side of the sleeve, there is disposed a second spring of the displacement setting device for biasing the sleeve in the other axial direction, the second spring being weaker than the first spring. At the starting of the compressor, the first spring holds the stopper at the stop position against a repulsive force of the second spring to hold the sleeve engaged with the stopper at a fixed position.

Abstract: A swash plate type compressor has a rotary shaft, an inclined swash plate for rotation with the shaft, and a plurality of pistons connected to the swash plate. Each piston defines at both ends thereof a pair of working chambers. The piston reciprocates while being subjected to a swing motion concomitant with the rotation of the swash plate, to suck a fluid into the working chambers for compression. The swash plate is mounted on the shaft through a support unit which serves to selectively vary the inclination of the swash plate and shift the center of rotation of the swash plate along the shaft. The fluid is introduced from a suction passage through and around the swash plate to suction chambers formed adjacent the working chambers. A bypass passage is formed to directly communicate the suction passage with the suction chamber on one side of the shaft while bypassing the swash plate.

Abstract: A variable displacement type compressor includes a casing having a working chamber and cylinder bores provided therein and opened to face to the working chamber. The cylinder bores are disposed around a driving shaft rotatably carried in the casing. A working piston is slidably received in each of the cylinder bores. A sleeve is axially slidably fitted over the driving shaft within the working chamber and carries a holder mounted for swinging movement about an axis perpendicular to an axis of the driving shaft and connected to the driving shaft. A swingable swash plate is carried on the holder and connected by rods to the working pistons. A control piston is connected to the sleeve and slidably received in the casing to vary the angle of inclination of the holder and the swingable swash plate and vary the stroke of the working pistons.

Abstract: A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a member having a surface with an adjustable incline angle. the incline angle is controlled by the pressure situation in the crank chamber. The pressure in crank chamber is controlled by control mechanism which comprises a passageway communicating between the crank chamber and a suction chamber and valve device to control the closing and opening of the passageway. The valve device includes a valve element which directly controls the closing and opening of passageway. A valve device includes a bellows valve element and a valve shifting element.

Abstract: A slant-plate type compressor including a compressor housing having a cylinder block as disclosed. A plurality of peripherally located cylinders are formed around the cylinder block, and a central bore is formed through the cylinder block. A piston is slidably fitted in each of the cylinders and is reciprocated by a drive mechanism. The drive mechanism includes a drive shaft rotatably supported in the compressor housing, and having one axial end terminating in the central bore. A rearward portion of the central bore is threaded, and an adjusting screw is screwed into the rear portion to adjust the axial position of the drive shaft within the central bore. A spacer is disposed between the inner axial end surface of the drive shaft and the adjusting screw. The spacer includes a plurality of radial projections extending from a peripheral surface, and fitting into corresponding depressions formed in the interior surface of the central bore.

Abstract: A capacity control arrangement controlling the capacity of a variable capacity wobble plate type compressor of a car air-conditioner driven by an engine of the car employs an engine load sensor, a compressor discharge pressure sensor, a car speed sensor, a compressor crankcase chamber pressure sensor, a miscellaneous air-conditioning data sensor, and a central processing unit to calculate and adjust a duty ratio value at which a solenoid-operated capacity control valve of the compressor is electrically driven. The adjustment of the duty ratio is carried out in such a manner when the engine load exceeds a predetermined value, the solenoid-operated capacity control valve first takes a fully open position to establish the lowest compressor capacity for an adjusted short period of time, and subsequently, takes a reduced opening position to maintain the lowest compressor capacity for as long as the engine load exceeds the predetermined value.

Abstract: A refrigerating system including a refrigerant circuit having a condenser, evaporator and wobble plate type compressor with a variable displacement mechanism. Two passages communicate between the crank chamber and the suction chamber in the cylinder block. A bellows is disposed in a first passage and controls the communication between the crank chamber and the suction chamber response to crank chamber pressure. A control valve is disposed in the second passage and controls communication between the crank chamber and the suction chamber in the second passage in response to a signal generated outside of the compressor. A control circuit controls the generation of the signal in response to thermodynamic characteristics related to the evaporator. The signal activates or deactivates the second control valve when the characteristic indicates a value beyond a predetermined range of values.

Abstract: A pressure-limiting valve coaxial with the drive shaft is installed in a multi-piston pump. The valve is biased by a compression spring to closed condition to prevent output flow from the pump into a pressure-collecting dome of the housing. The spring is supported for reaction against a gasket having a throttle bore leading directly for flow toward a return chamber wherein the end of the pump shaft is a radial wall. When pressure in the pressure-collecting dome reaches a certain value, it will open the pressure-limiting valve against spring bias to relieve pressure through the throttle bore back into the suction channels of the pump. However, the relief flow through the throttle bore causes heating of the oil, an effect which is an important purpose of the invention on pump start-up. Thus, by making the return flow of reduced viscosity due to heating, such oil impinging against the shaft of the pump does not cause a sudden shift of the shaft against the pump housing.

Abstract: A slant plate type compressor with a capacity or displacement adjusting mechanism. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a member having a surface with an adjustable incline angle. The incline angle is controlled by the pressure condition in the crank chamber. The pressure in the crank chamber is controlled by a control mechanism which comprises a passageway communicating between the crank chamber and a suction chamber, and valve to control the closing and opening of the passageway. The valve is disposed in a central bore which is formed in the cylinder block and supports one end of a drive shaft. A conduit extends from the central bore through the cylinder block and to the suction chamber.

Abstract: A pressure control valve for a variable displacement swash plate type compressor includes a valve element movable under a combined force of the force of a pressure responsive member and the force of a solenoid. The valve element is engageable with a valve seat which is positionally adjustably mounted on a valve case of the pressure control valve and movable in the direction of movement of the valve element. The solenoid includes an armature to which an adjustment screw is threadedly connected. The extent of the adjustment screw which projects from the armature is adjustable so that the position of the valve element is adjustable relative to the valve seat. With this arrangement, it is possible to adjust the pressure controlling characteristics exactly.

Abstract: A reciprocating piston type refrigerant compressor includes a compressor housing having a cylinder block provided with a plurality of cylinders and a crank chamber adjacent the cylinder block. A piston slides within each cylinder and is reciprocated by a wobble plate driven by a cam rotor mounted on a drive shaft. The cam rotor includes an adjustable slant angle in close proximity to the wobble plate. Accordingly, the stroke of the pistons within the cylinders can be changed by adjusting the slant angle of the sloping surface. The slant angle of the sloping surface is adjusted in response to the change of pressure in the crank chamber. The crank chamber communicates with the suction chamber through a passageway and a valve control mechanism controls the opening and closing of the passageway. Thus, the capacity of the compressor of can be adjusted by changing the slant angle of the sloping surface of the slant plate in response to the operation of the valve control mechanism.

Abstract: A slant plate type compressor with a variable displacement mechanism includes a compressor housing having a cylinder block with a plurality of cylinders which are associated with a suction chamber. The compressor also comprises a crank chamber adjacent the cylinder block, a piston slidably received within each of the cylinders, and a drive mechanism coupled to the cylinders. The drive mechanism includes a drive shaft rotatably supported in the housing, a rotor coupled to the drive shaft and rotatable therewith, and a coupling mechanism for drivingly coupling the rotor to the pistons such that the rotary motion of the rotor is converted into reciprocating motion of the pistons. The coupling mechanism includes a member having a surface disposed at an incline angle relative to the drive shaft wherein the incline angle is adjustable to vary the stroke length of the pistons and the capacity of the compressor. The coupling mechanism also includes a hinge mechanism between the rotor and the incline member.

Abstract: A wobble plate type compressor is equipped with a device which can be selectively activated in a manner to induce the wobble plate to assume a position wherein the displacement of the compressor is reduced to zero and thus obviate the need for a clutch for such purposes. The device further includes an arrangement which biases the wobble plate toward a position wherein a positive displacement of the compressor will occur when in a non-activated state. The strength of this bias is insufficient to interfere with the control of the wobble plate inclination by the pressure prevailing in the chamber in which the plate is disposed.

Abstract: A refrigeration system includes a variable-capacity compressor having a compression chamber for sucking and compressing a refrigerant and a crankcase surrounding a swash plate forming a drive portion for suction and compression, and a passage through which the refrigerant discharged from the outlet of the compression chamber passes at least through a condenser, an expansion means and an evaporator and is sucked into the inlet of the compression chamber of the compressor, the capacity of the compressor being changed by slanting the swash plate during its rotation. A pressure control device is provided in a refrigerant passage between the evaporator and the suction valve of the compressor whereby the pressure upstream thereof is controlled in such a manner that it does not decrease below a predetermined value, thereby preventing frosting of evaporator fins.

Abstract: A wobble plate compressor with a variable displacement mechanism is disclosed. The compressor includes a compressor housing having a crank chamber and a cylinder block. A plurality of cylinders is formed in the cylinder block. A drive shaft is rotatably supported in the housing. A rotor is fixed on the drive shaft and is hingedly connected to an inclined plate through a hinge mechanism. The hinge mechanism includes a first arm portion which is formed on either the rotor or inclined plate, a second arm portion having an elongated hole on the other of the rotor or the inclined plate, and a guide pin fixedly disposed in the hole of the first arm portion. A wobble portion is disposed adjacent the inclined plate and converts rotational motion of the inclined plate into nutational motion. A plurality of pistons are coupled to the wobble plate through a plurality of piston rods. Each piston is reciprocatingly fitted within a respective one of the cylinders.

Abstract: A slant plate type compressor, such as a wobble plate type compressor, with a variable displacement mechanism is disclosed. The compressor has a valve mechanism to control the opening and closing of a passageway connected between the crank chamber and suction chamber. The valve mechanism operates in accordance with the pressures in the crank chamber and the suction chamber of the compressor. Therefore, the compressor has improved cooling characteristics and lubricating oil does not leak out of the compressor into the external refrigeration circuit.

Abstract: A refrigerant compressor including a compressor housing having a cylinder block is disclosed. A plurality of cylinders are formed around the periphery of the cylinder block. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism. A crank chamber is formed between the cylinder block and a front end plate of the compressor housing. The drive mechanism includes a drive shaft, a rotor disposed on the drive shaft, a slant plate with an adjustable slant angle disposed adjacent the rotor and a wobble plate disposed adjacent the slant plate. The drive shaft is rotatably supported within the front end plate. Rotation of the drive shaft causes rotation of the rotor and the slant plate, causing nutational motion of the wobble plate to reciprocate the pistons within their cylinders. The compressor housing includes a rear end plate defining suction and discharge. A communicating path communicates between the crank chamber and the suction chamber.

Abstract: A variable wobble plate type compressor with a variable angle non-rotary wobble plate, having a suction chamber for a refrigerant before compression, a discharge chamber for a compressed refrigerant, compressing cylinder bores, pistons reciprocated by the wobble plate within the cylinder bores for compressing the refrigerant, a crankcase having a chamber to receive therein a drive and a wobble plate mechanism connected to the pistons to cause the reciprocating motion of the pistons and capable of changing the wobble angle thereof, a first passageway closably opened so as to apply a high discharge gas pressure of the discharge chamber to the drive and wobble plate mechanism within the crankcase chamber, a solenoid-operated plunger valve for controlling an introduction of a high pressure refrigerant gas from the discharge chamber into a high pressure chamber arranged in a part of the first passageway in response to a change in a cooling load, and a second passageway providing a fluid communication between the c