Abstract: An accurate and low cost sensing apparatus for a swash or wobble plate compressor that requires no modifications in compressor design or operation, and which provides a repeatable and accurate measure of compressor speed and stroke. The apparatus includes a sensor module and a stroke sensing circuit. The compressor has an outer housing formed of aluminum or other non-magnetic material, as is customary in automotive air conditioning systems. The sensor module includes a magnetic field responsive sensor such as a Hall Effect or magneto-resistive (MR) sensor, and is attached to the periphery of the housing in proximity to a reciprocating ferrous element such as a bushing shoe on the swash or wobble plate assembly. The sensor produces a quasi-sinusoidal output voltage signal having a frequency proportional to compressor speed, and the stroke sensing circuit determines the compressor stroke by band-pass filtering, amplifying, and peak detecting the signal.

Abstract: A hydraulic pilot circuit having a pilot pump which discharges pilot oil, and a plurality of pilot valves which control a plurality of hydraulic directional control valves by supplying the pilot oil with control, wherein heating of hydraulic oil due to retaining pilot pressure oil is reduced, and controllability is not damaged even if the plurality of pilot valves are operated at the same time, because sufficient pilot oil is supplied to the pilot valves. A variable displacement pump is adopted as the pilot pump. An operation detecting means detects operating condition of the hydraulic pilot valves, a controller computes the necessary discharge of the pilot pump for operating the hydraulic directional control valves from the operating condition, and the pilot pump discharges only the necessary oil flow.

Abstract: A variable displacement compressor includes a rotary valve which can rotate synchronously with a drive shaft. The rotary valve includes a center hole with one end closed and with the other end in constant communication with a suction chamber, and a communicating hole intermittently provide a fluid communication between the center hole and a gas extracting passage extending from a crank chamber along with the rotation of the rotary valve. The amount of refrigerant gas flowing back from the crank chamber to the suction chamber through the gas extracting passage is reduced by exactly the amount of the refrigerant gas which can flow through the gas extracting passage unless it is closed by the rotary valve.

Abstract: A variable capacity swash plate type compressor 10 incorporates a swash plate 34 to effect movement of at least an associated piston 44 to vary the capacity of the compressor 10. The structure of the swash plate 34 and piston 44 minimize the bending moment exerted on the piston 44 during operation.

Abstract: A reciprocating refrigerant compressor having a cylinder block provided with a plurality of cylinder bores in which a refrigerant gas sucked from a suction chamber is compressed to be subsequently discharged into a discharge chamber, a valve plate having suction ports through which the refrigerant gas is sucked into the respective cylinder bores and discharge ports through which the compressed refrigerant gas is discharged, a suction valve attached to one end face of the valve plate, a discharge valve attached to the other end face of the valve plate, a housing assembly attached to the cylinder block and having the suction and discharge chambers, and a sealing unit arranged in one of boundaries between the end face of the cylinder block and the suction valve, and between the suction valve and the valve plate to provide an annular sealing portions around each of the bore ends of the plurality of cylinder bores.

Abstract: A pump (10) includes a motor (11) which rotates a pumping assembly (52) which includes a face plate (54) and a cylinder (56). A piston (67) reciprocates in the cylinder (56) to draw fluid into the cylinder (56) from an intake groove (78) and an intake port (76) formed in a manifold plate (73) positioned adjacent to the face plate (54), and to thereafter discharge that fluid to a discharge groove (80) and a discharge port (77) formed in the manifold plate (73). The piston (67) rides on a swash plate (49) as the face plate (54) rotates, and the extent of reciprocation of the piston (67) and therefore the amount of fluid to be dispersed on each reciprocation of the piston (67) is controlled by an adjuster wheel (40) which can be moved to allow the swash plate (49) to pivot a predetermined extent. As such, the pump (10) can dispense a known precise amount of fluid on each reciprocation of the piston (67).

Abstract: In a swash plate type compressor, a swash plate (22) is fixed to a boss (21) by means of rivets (35). The swash plate is coupled to a plurality of pistons (24) via shoes (25). When a main shaft (16) is rotated to rotate a rotor (18), a rotational motion of the rotor is transmitted to the boss via a hinge mechanism (19) which changes an inclination of the swash plate. Accordingly, the boss is rotated to rotate the swash plate at the inclination to cause the pistons to make reciprocating motions in cylinders (26) via the shoes for performing a compressing operation.

Abstract: A control valve for a variable capacity compressor; wherein an opening degree of a valve member disposed in a coolant gas passage for communicating a discharge pressure region of the variable capacity compressor with a crankcase thereof is made adjustable by a magnetization action of a solenoid, thereby causing an inclination angle of a wobble plate to change and also causing a discharging capacity of the compressor to change; and which is characterized in that the main valve body comprises a solenoid, a pressure sensitive chamber provided with bellows and a valve chamber provided with the valve member, and that the solenoid is provided with a plunger connected with one end of a stem, whose other end of the stem being detachably contacted with a stopper of the bellows, and the other end of the plunger being linked to a rod to be contacted with the valve member.

Abstract: A variable swash plate compressor (10), including a housing (12), a top inlet (14A), a bottom inlet (14B) , a pumping chamber (16), a compression piston (18), a top outlet (20A), a bottom outlet (20B) , a drive shaft (22) , a control surface element (24), a pinnacle element (26), a swash plate (28), a bore (30) and a pocket (32) formed in the swash plate (28), a pivot element tip (38) and fulcrum piston assembly (40). Wherein the angle of the swash plate (28) relative to the drive shaft (22) is varied to bring about a larger or smaller travel path of the compression piston (18) and thereby increasing or decreasing the output capacity of the variable swash plate compressor (10).

Abstract: A device for varying the displacement of a variable displacement bent axis unit includes a one-piece yoke having a bucket portion adapted to carry a cylinder block kit of the bent axis unit, a trunnion bearing portion for swing control on one side of the bucket portion, and a trunnion portion for fluid porting on the other side of the bucket portion. The bucket portion has a bottom wall, a continuous side wall, and an open top. Inside the yoke is a pair of fluid passages intersecting the interior of the bucket portion and extending separately and entirely within the bottom wall and the side wall before opening onto the trunnion portion for fluid porting.

Abstract: A torque control system for a hydraulic pump in a hydraulic construction machine wherein if an engine output lowers due to change of the environment, modification gain calculating portions 70m-70u and a torque modification value calculating portion 70v receive signals detected by sensors 75-82 and estimate a lowering of the engine output power as a torque modification value &Dgr;TFL. A speed sensing torque deviation modifying portion 70i subtracts the torque modification value &Dgr;TFL from a speed sensing torque deviation &Dgr;T1. A resulting torque modification &Dgr;TNL is added to a pump base torque TR0 to determine a suction torque TR1 (target maximum suction torque), and a resulting signal is output to a solenoid control valve 32. The solenoid control valve 32 controls respective servo valves 22 for total horsepower control, thereby controlling the maximum suction torque of the hydraulic pumps 1, 2.

Abstract: A swash plate type compressor comprises a case; a drive shaft rotatably installed in the case; a drive plate fixed to the drive shaft to rotate therewith; a sleeve axially slidably disposed on the drive shaft; a journal pivotally mounted on the sleeve; a swash plate disposed on the journal to move therewith; and a transmission/hinge mechanism arranged between the drive plate and the journal to transmit the rotation of the drive shaft to the journal permitting the pivotal movement of the journal relative to said sleeve. The transmission/hinge mechanism includes a first arm projected from the drive plate and having an elongate through hole; two spaced second arms projected from the journal, the second arms being so spaced as to intimately put therebetween the first arm, the second arms having cylindrical bores which are aligned; and a pin including a middle portion slidably received in the elongate through hole and axially opposed end portions press-fitted in the cylindrical bores of the second arms.

Abstract: A variable displacement hydraulic piston unit with electrically operated variable displacement control and timing control is disclosed, the displacement control utilizing an electric motor such as a stepper motor and cam arrangement operable for changing the tilt angle of a swash plate of the unit, and the timing control including an electric motor, such as a stepper motor operable for rotating the swash plate relative to the pistons of the unit for effecting timing changes, the unit being operable as a pump, motor, or the like.

Abstract: An axial piston machine (1) which includes a cylinder block (2) having cylinder bores (3, 4) in which pistons (5, 6) are movably guided, with the pistons (5, 6) being supported on an inclined or wobble plate (25) in order to perform a lifting movement. The axial piston machine (1) further includes a pivot device (31) for varying the inclination of the inclined or wobble plate (25) by pivoting about a pivot axis (27). Provided is a damping element (41) which includes a damping piston (40) which acts on the inclined or wobble plate (25) and is movably disposed in a damping cylinder (42) which is connected to a pressure fluid reservoir (48) via a throttle element (47) and a non-return valve (44) is disposed parallel thereto.