Abstract: A hydraulic system and work machine are provided, the hydraulic system including at least one hydraulic cylinder with a first port and a second port connected by a first fluid passage. A first pump, which is a bi-directional hydraulic pump is positioned within the first fluid passage, and a second pump is positioned in parallel with the first pump and disposed within a second fluid passage. An accumulator fluidly connects with the second fluid passage.

Abstract: The invention relates to a hydraulic drive system used for the covers of vehicle openings, in particular for vehicle roofs with a construction that can be opened. In said system, the actuator that is designed to displace the cover is supplied with a bulk current, whose target value is determined in accordance with the control path of the actuator, which is in correlation with the controlled displacement of the cover and whose actual value is detected when supplied to the actuator by means of a bulk current sensor. The bulk current is adjusted to compensate for differences between the actual and target values.

Abstract: A power steering system includes a reversible-type oil pump supplying hydraulic fluid to first and second pressure chambers of a hydraulic power cylinder through first and second passages and having first and second discharge ports, and a branch passage conveying part of hydraulic fluid discharged from the discharge ports of the oil pump to the outside of the pressure chambers of the power cylinder, wherein the branch passage has a passage sectional area greater than a total leak sectional area of the oil pump.

Abstract: An invented dual, coupled check valve mechanism is described for a direct drive, reversible hydraulic power source for hydraulic circuits that includes a manifold hydraulically coupled to the respective input/output ports and a reservoir of the hydraulic power source defining a translation passageway having mid-passage drain hydraulically coupled to the reservoir, where each end of the translation passageway has an angled annular valve seat opening to larger diameter plenum containing a check valve ball. A translating rod with a length greater and a circumferential diameter less than that of the translation passageway located in the translation passageway prevents the respective check valve balls from simultaneously seating on the valve seats at the respective ends of the translation passage way.

Abstract: An actuator comprises a pump-driving section which is driven and rotated by a current, and a pump mechanism which is connected to the pump-driving section and which sucks/discharges a pressure oil. A cylinder mechanism, which has a piston that is displaceable in the axial direction by being supplied with the pressure oil, is provided on the pump-driving section and the pump mechanism. The amount of discharge of the pressure oil to the cylinder mechanism is adjusted by freely changing the angle of inclination of a tilting member provided in the pump mechanism.

Abstract: An electrohydraulic actuator (10) includes a fluid-powered actuator (11) having a piston (15) in a cylinder (16). The piston divides the cylinder into two opposed chambers (18, 19). The actuator includes a fixed-displacement reversible motor-driven pump (13) having a first port communicating with one of the chambers and having a second port communicating with the other of the chambers in a closed hydraulic system. A pre-charged accumulator (14) communicates with the pump first port. One of the actuator chambers is maintained at a fixed pre-charged pressure of the accumulator, and the operation of the pump controls the pressure in, and volume of, the other chamber.

Abstract: An oil pressure operated pump for marine steering gears includes a multiple piston oil pressure operated pump controlled by a steering wheel, a valve housing mounted under the pump, a bottom cover closing the valve, the valve housing and the cover each including channels, threaded holes for reciprocal fastening thereof, non-threaded bores for oil pressure connections, a valve set lodged in the valve housing for non-return and adjustment of oil flow, the valve set including a generally parallelepiped shaped tubular shell having a generally external square shape, a central tubular through-hole, and lathe-turned ducts, a double acting oil pressure cylinder including a shaft movable in the central tubular through-hole for controlling a direction of an engine or rudder of a boat, and valves for controlling fluid flow and thereby movement of the shaft.

Abstract: A novel bi-rotational pump adapted to pump fluid in either of two directions by reason of construction inclusive of passageways and an array of check valves and pilot pistons which cooperate in one direction and in another way in the other direction.

Abstract: A power steering system includes: a first drain passage for draining an oil pressure from a first oil passage, a second drain passage for draining the oil pressure from a second oil passage, and a pair of a first and second switch valves. When one of the first oil passage and the second oil passage is so pressurized by an operation of a reversible oil pump as to have an increased internal pressure, the pair of the first switch valve and the second switch valve allow the following: i) closing one of the first drain passage and the second drain passage which one is connected to the oil passage having the thus increased internal pressure, while ii) opening the other of the first drain passage and the second drain passage which other is connected to the oil passage that is so depressurized as to have a decreased internal pressure.

Abstract: A cylinder driving system capable of reducing the number of hydraulic devices and the amount of energy loss and an energy regenerating method thereof are provided. To this end, the system includes i) a hydraulic cylinder, ii) a hydraulic pump having three suction/discharge ports of a first port for supplying oil to a bottom chamber of the hydraulic cylinder or draining oil from the bottom chamber, a second port for draining oil from a head chamber of the hydraulic cylinder or supplying oil to the head chamber, and a third port for draining oil from a tank or supplying oil to the tank, the suction rate or the discharge rate in the first port being the sum of the respective discharge rates or suction rates in the second port and the third port, and iii) a driving source for driving the hydraulic pump.

Abstract: An electro-hydrostatic actuator unit that contains a sealed pressurized housing filled with a dielectric fluid. A bi-directional motor is immersed in the fluid and drives a gear pump for exchanging fluid via a control circuit between the chambers of a bi-directional hydraulic actuator in response to an input from a controller. The chambers are separated by a piston and a piston rod is connected to an external load such as a plunger type valve. A failsafe circuit is also provided which is arranged to override the control circuit in the event a failsafe condition is detected by the unit controller. The failsafe circuit contains a motor driven pump that provides high pressure fluid from the pressurized reservoir to an accumulator. Valves are arranged to shut down the control circuit and deliver fluid from the accumulator to one of the cylinder chambers to rapidly move the actuator to a desired failsafe position.

Abstract: A hydraulic system for an actuator provides staged operation during extend and retract. A pair of reversible pumps are conjointly driven by a reversible motor. A relief valve in the retract circuit directs fluid to tank when fluid pressure increases above a predetermined value. An unloader valve in the extend circuit is responsive to pressure at a first stage pump to direct flow to tank when the pressure increases above a second predetermined value. A non-return check valve connected between the pumps in the extend circuit closes the flow circuit to the second stage pump during high loads, so that the flow from the second stage pump goes to tank, and the return flow from the actuator goes only to the first stage pump. The non-return check valve is responsive (via a signal line to the retract circuit portion) to the pressure in the extend and retract circuit portions.

Abstract: A power steering system includes: a first drain passage for draining an oil pressure from a first oil passage, a second drain passage for draining the oil pressure from a second oil passage, and a pair of a first and second switch valves. When one of the first oil passage and the second oil passage is so pressurized by an operation of a reversible oil pump as to have an increased internal pressure, the pair of the first switch valve and the second switch valve allow the following: i) closing one of the first drain passage and the second drain passage which one is connected to the oil passage having the thus increased internal pressure, while ii) opening the other of the first drain passage and the second drain passage which other is connected to the oil passage that is so depressurized as to have a decreased internal pressure.

Abstract: A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons.

Abstract: An actuating device (1) for carrying out mechanical work by means of a slave piston rod (5) in a hydraulically-operated slave cylinder (2), where the actuating device (1) is made up of a hydraulic pump (3) integrated with a slave cylinder (2) and where the hydraulic pump (3) is driven by a linear electric motor, which consists of a pump piston (7) which is used as rotor in the linear motor at the same time as the pump piston (7) functions as a pumping piston in the hydraulic pump (3) to build up a hydraulic pressure in the slave cylinder (2).

Abstract: A hydraulic pump for a closed-loop hydrostatic transmission circuit having an integrated shuttle valve for diverting hot fluid from the hydrostatic transmission circuit to a reservoir. The circuit operatively interconnects the hydraulic pump and a motor and includes a first line connecting a first port within the hydraulic pump to a first port within the motor and a second line connecting a second port within the hydraulic pump to a second port within the motor.

Abstract: The invention relates to an architecture for a hydraulic steering control system including at least one actuator; the hydraulic system comprises a directional-control valve connected to a pressure-generator device and to an associated main supply, the hydraulic system further comprising a reversible electrically-driven pump unit having two ports and being fitted with a general selector arranged, in a normal mode of operation, to put the chambers of the actuator into communication with the directional-control valve, and in an alternate mode of operation to put the chambers of the actuator into communication with the ports of the pump unit. A compensation device makes it possible in the alternate mode to compensate for any flow differential between the flow drawn in by the pump unit from one of the chambers of the actuator and the flow delivered by the pump unit into the other chamber of the actuator.

Abstract: A hydraulic actuating device, for a vehicle cover and an associated lock for locking the cover in the closed position, has a cover actuator and a lock actuator which each are provided with a first and second connection, which are respectively in communication with an associated first and second opening adjoining the actuator space. The cover actuator is provided with a third opening, which is connected to the second connection of the lock actuator. The first connection of the cover actuator and the first connection of the lock actuator are connected to a common connecting line with a single actuable valve, which in a first position connects the delivery port of the pump to the connecting line. The second connection of the cover actuator is in communication with the delivery port of the pump.

Abstract: A hydraulic actuating device for a closure assembly, for example of a vehicle, which closure assembly comprises a closure element which can be moved between a closed position, in which the closure element closes off an opening, and an opened position. The hydraulic actuating device comprises a hydraulic actuator for moving the closure element, which actuator has a housing having a closing chamber and an opening chamber. Further provided are a hydraulic pump having an associated electric pump motor and a reservoir for hydraulic fluid. The hydraulic actuating device further comprises a first pressure-limit valve, which is connected to the opening chamber, and a second pressure-limit valve, which is connected to the closing chamber. Control means are further provided for controlling the supply of hydraulic fluid under pressure to the opening chamber or to the closing chamber of the actuator.

Abstract: The linear actuator comprises two variable-volume chambers (5) containing an operative liquid, each of the chambers (5) being delimited on one side by one of two mobile elements (4), which mobile elements (4) are solidly constrained one to another. One of the mobile elements (4) is connectable to an external user, for example a gearwheel of a gear coupling. A geared rotary positive displacement pump (10) reversibly transfers the operating liquid from one chamber (5) to the other chamber (5) through an infeed conduit (6), to move the mobile elements (5) selectively in one direction or another. A recycling conduit (7), narrower than the infeed conduit (6), places the two chambers (5) in communication and realizes a closed circuit, in a situation where the mobile elements 4) are stationary and the pump (10) is active.

Abstract: The invention pertains to a hydraulic swinging-leaf door drive for swinging doors with an actuating piston, which acts on a drive shaft, and with a hydraulic pump, which acts on the actuating piston by way of a hydraulic circuit. To create a hydraulic swinging-leaf door drive of the type explained above, which is improved from a technical standpoint, which occupies only a small amount of space, and which is also suitable for installation under cover, it is provided according to the invention that the hydraulic circuit is designed as a closed circuit.

Abstract: A hydraulic press which is small in the temperature rise of hydraulic oil, which can dispense with a water-cooling cooler, which is compact in size and which can realize energy saving is provided. A pressure receiving area of a high speed descent first cylinder chamber 51 and a pressure receiving area of a high speed ascent second cylinder chamber 52—are set equal to each other, and a closed circuit which ranges from the second cylinder chamber 52 to the first cylinder chamber 51 through a hydraulic passage 31, a hydraulic pump 7 and a hydraulic passage 34 is constituted. Using an alternating current servo motor 6, the number of revolutions of the hydraulic pump 7 in positive and counter directions is controlled to thereby control advancement and regress speeds and pressure of a piston member 54.

Abstract: A pair of flexible actuators according to the present invention is supported by a fixture made of a hard rubber at base ends of the flexible actuators. Each flexible actuator includes a movable unit that is capable of bending, a pump unit integrally connected to the movable unit at an end thereof, to control transfer of work fluid sealed in the movable unit, and a pump driver that controls driving of the pump unit. The movable unit includes two long and narrow tubes that each have an accordion wall, a core that maintains the tubes in parallel with each other, and a thin-film-bag-like cover that covers the tubes. The tube, which comes into contact with an object, is made of a soft material. The movable unit that is provided with the tube softly comes into contact with the object at a plurality of plane-contact portions of action of the movable unit, thereby holding the object without scratching the same.

Abstract: An electric motor and hydraulic pump/motor are combined on a torque level, a press machine is controlled with controllability of an electric motor, and kinetic energy of a slide is regenerated during braking without constraints of slide pressurization or an amount of energy. A screw press drives a slide through a screw mechanism made up of a drive nut and a driven screw. The drive nut is provided with a ring gear integral therewith and this ring gear is engaged with a gear provided for a drive axis of an electric motor and a gear provided for the drive axis of a hydraulic pump/motor. The hydraulic pump/motor is connected to a constant high pressure source that generates a quasi-constant pressure hydraulic liquid and a low pressure source. This allows the electric motor and hydraulic pump/motor to be combined on a torque level.

Abstract: The invention proposes a novel drive with electrical power control for machines which have to execute cyclic movements with high accelerations. An electric motor drives a pump which, in turn, is connected directly to a cylinder. This arrangement has added to it a system of pressure accumulators and valves which give the system the property of an oscillator. The acceleration forces in the event of a cyclic movement near to resonance are then exerted largely by the pressure accumulators and the cylinders connected to these. This leads to a relieving of the electric motor and makes it possible to install lower powers on the machine or else, for the same power, achieve shorter cycle times of the machine.

Abstract: A cylinder driving system capable of reducing the number of hydraulic devices and the amount of energy loss and an energy regenerating method thereof are provided. To this end, the system includes i) a hydraulic cylinder, ii) a hydraulic pump having three suction/discharge ports of a first port for supplying oil to a bottom chamber of the hydraulic cylinder or draining oil from the bottom chamber, a second port for draining oil from a head chamber of the hydraulic cylinder or supplying oil to the head chamber, and a third port for draining oil from a tank or supplying oil to the tank, the suction rate or the discharge rate in the first port being the sum of the respective discharge rates or suction rates in the second port and the third port, and iii) a driving source for driving the hydraulic pump.

Abstract: An electrically controlled hydraulic actuating system includes a servocontrol including a cylinder, a piston dividing the cylinder into two chambers each provided with a hydraulic connection port, a control valve connected to a hydraulic circuit. A two-way hydraulic pump is driven in rotation by an electric motor driven by power electronics. A switching device allows the connection ports of the chambers to be connected either to the control valve or the pump. The switching device connects the hydraulic connection ports both to the control valve and the pump, so as to allow the servocontrol to be supplied the sum of the hydraulic power delivered by the hydraulic circuit and the hydraulic power generated by the pump actuated by the electric motor.

Abstract: An hydraulic power system having a reversible motor operating a pump to deliver liquid under pressure to operate an actuator mechanism, where the motor is submerged within the liquid inside a reservoir. Flow direction of the liquid is controlled by alternating the direction of rotation of the motor and pump.

Abstract: The invention relates to an architecture for a hydraulic steering control system including at least one actuator; the hydraulic system comprises a directional-control valve connected to a pressure-generator device and to an associated main supply, the hydraulic system further comprising a reversible electrically-driven pump unit having two ports and being fitted with a general selector arranged, in a normal mode of operation, to put the chambers of the actuator into communication with the directional-control valve, and in an alternate mode of operation to put the chambers of the actuator into communication with the ports of the pump unit. A compensation device makes it possible in the alternate mode to compensate for any flow differential between the flow drawn in by the pump unit from one of the chambers of the actuator and the flow delivered by the pump unit into the other chamber of the actuator.

Abstract: The invention relates to a hydraulic drive with a plurality of hydraulic consumers also comprising a differential cylinder which are located in particular on a plastics injection-molding machine. There are a first hydraulic machine and a second hydraulic machine, which can both operate as pump and as motor. A first of the two hydraulic machines is connected to a tank by means of a second port and rests against a pressure line by means of a first port, which pressure line can be connected to that working chamber of the differential cylinder which is remote from the piston rod via a shut-off valve. The second hydraulic machine is likewise connected to the pressure line by means of a first port and can be connected, by means of a second port, to a tank via a nonreturn valve which opens toward the second port and to the piston-rod-side working chamber of the differential cylinder via a shut-off valve.

Abstract: A drive device comprising a closed hydraulic circuit which has a hydraulic drive adapted to be actuated by hydraulic medium and has a hydraulic pump responsible for the supply and removal of the hydraulic medium to and from the hydraulic drive. For the operation of the hydraulic pump an electric motor is provided. The activation of the hydraulic drive is controlled by the operational state of the hydraulic pump.

Abstract: A hydraulic actuating device for a closure assembly, for example of a vehicle, which closure assembly comprises a closure element which can be moved between a closed position, in which the closure element closes off an opening, and an opened position.

Abstract: A hydraulic control device having a first hydraulic actuator provided with a cylinder space, in which a piston/piston rod assembly is accommodated in such a way that it can move to and fro between first and second end positions.

Abstract: A control system for swing cylinders to position a boom on a backhoe or the like includes a pair of double acting hydraulic cylinders on the backhoe frame operatively connected to the boom for swinging the boom with respect to the frame, a closed circuit pump arranged in a closed circuit with the hydraulic cylinders such that the control on the pump is the sole means of controlling the cylinders.

Abstract: A hydraulic actuating unit for integration into a preassembled folding roof unit of a motor vehicle is adapted for mounting as a single unit in a motor vehicle with the hydraulic actuating unit integrated therein. The preassembled folding roof unit has a folding roof with a foldable cover and a framework for the cover. A main bow is pivoted by a hydraulic main bow actuator and a rear bow is pivoted by a hydraulic rear bow actuator, each actuator being of the double-acting type. The hydraulic actuating unit also has an actuable two-position control valve, which control valve has an outlet port, an inlet port and a reservoir port, the outlet port being connected to a working chamber of the main bow actuator and/or a working chamber of the rear bow actuator. The control valve, in a first position, connects the associated outlet port to the reservoir port and, in a second position, connects the associated outlet port to the inlet port of the control valve.

Abstract: In an hydraulic operating arrangement the working chambers (3, 4) of a double-acting working cylinder (1) are connected respectively by way of one reciprocally unlockable check valve (8, 9) with respectively one side of a reversible pressure medium source (11). The respective working chamber (3, 4) under pressure is connected with a joint, controllable proportional pressure regulating valve (15) for pressure control. On its exit side the proportional pressure regulating valve is connected with the pressure medium lines (6, 7) by way of respectively one check valve (18, 19) that opens in the direction of the pressure medium lines (6, 7), in particular between the corresponding unlockable check valves (8, 9) and the respectively belonging working chamber (3, 4) of the working cylinder (1).

Abstract: An hydraulic power system having a reversible motor operating a pump to deliver liquid under pressure to operate an actuator mechanism, where the motor is submerged within the liquid inside a reservoir. Flow direction of the liquid is controlled by alternating the direction of rotation of the motor and pump.

Abstract: The invention concerns a hydraulic circuit (17) and a control valve (18) dimensioned to be capable of providing the greater part the control surface (3) actuating, which requires less power than the system maximum performances Moreover, a bi-directional hydraulic pump (23), driven by an electric motor (24), can supply backup power which added to said circuit (17) power can ensure said maximum performances.

Abstract: The invention proposes a novel drive with electrical power control for machines which have to execute cyclic movements with high accelerations. An electric motor drives a pump which, in turn, is connected directly to a cylinder. This arrangement has added to it a system of pressure accumulators and valves which give the system the property of an oscillator. The acceleration forces in the event of a cyclic movement near to resonance are then exerted largely by the pressure accumulators and the cylinders connected to these. This leads to a relieving of the electric motor and makes it possible to install lower powers on the machine or else, for the same power, achieve shorter cycle times of the machine.

Abstract: The two working chambers (2, 2′, 3) of a working cylinder (1) of a hydraulic actuation arrangement may be directly connected with one another via a switchable dual-position valve (11), if necessary, whereby a resistance-free manual displacement of the components to be actuated is possible to a large extent—regardless of the working cylinder (1) that is driven by the hydraulic circuit (6) or also in case of a malfunctioning or a turned-off pressure medium source.

Abstract: A hydraulic system for a motor vehicle having a convertible top (2) which can be folded back has a convertible-top control system (1) and further hydraulic control devices (3, 4) which can be activated by a common hydraulic pump (6). In hydraulic lines (8, 9) leading to the convertible-top control system (1) there are arranged hydraulic valves (13, 14) which enable optional operation of the convertible-top control system (1) or of the further control devices (3, 4). Because of this, the hydraulic system turns out to be particularly simple structurally.

Abstract: Apparatus for compensating for positioning, pointing and/or orientation errors caused by deflections of structural members and components of a high performance machine or device and/or for reducing vibration inputs to such machine or device and/or for micro-positioning such machine or device so as to improve the operational performance of such machine or device. The apparatus utilizes one or more active-type actuators, such as piezoelectric ceramic type actuators, which are arranged in a predetermined manner relative to the machine or device. A servo control device operating in accordance with a predetermined algorithm may be utilized for controlling the actuators or, alternatively, the apparatus may operate in an open loop manner.

Abstract: A parking brake for a rail car vehicle including an electric motor driving a hydraulic pump fluidly connected to and controlling a bidirectional hydraulic actuator coupleable to the rail car's wheel brakes. An electric controller is connected to the pump and controls activation/deactivation of the pump with the controller including various switches. Also included is a coupler for coupling the actuator to one of a brake beam or an actuator of the parking brake.

Abstract: A control circuit, in particular for a slewing gear of a digger, has a hydraulic fluid tank (21), connected to two adjusting pressure chambers (10, 11). Each of the connections contains a separate brake valve (19, 20). The first of the valves (19) is operated by the differential between the working pressure in the first working conduit (2), and the control pressure in the control conduit (33, 34) charged with the higher pressure. The second valve (20) is operated by the differential between the working pressure in the second working circuit (3) and the control pressure in the control circuit charged with the higher pressure. Slow braking by the brake valves is interrupted when the slewing gear swings out against a resistance such as a heap of debris.

Abstract: A drive device comprising a closed hydraulic circuit which has a hydraulic drive adapted to be actuated by hydraulic medium and has a hydraulic pump responsible for the supply and removal of the hydraulic medium to and from the hydraulic drive. For the operation of the hydraulic pump an electric motor is provided. The activation of the hydraulic drive is controlled by the operational state of the hydraulic pump.

Abstract: A hydraulic operating apparatus, especially for a vehicle covering, includes a reversible pump (2) which, via hydraulic lines (3, 4), one of which is in all cases provided with an unblockable check valve (7), is connected with the working chambers of at least one double-acting piston-cylinder arrangement (1). In order to make possible a very flexible supply and control of mutually independently operated piston-cylinder arrangements with a minimum of constructive and control-technical effort, additional hydraulic lines (10, 11) branch off from both hydraulic lines (3, 4) of the reversible pump, into which the check valves are placed, which additional hydraulic lines lead into a common hydraulic line (12) to at least one additional piston cylinder arrangement (13, 14).

Abstract: Hydraulic control unit, in particular for the folding roof of a vehicle, comprising a reservoir for hydraulic fluid, a pump for drawing hydraulic fluid out of the reservoir and provided with a delivery port for delivering compressed hydraulic fluid, and also at least one first hydraulic actuator of the double-acting type with a first and a second variable working chamber, which working chambers are separated by a piston and are provided with a first and a second connection respectively for supplying hydraulic fluid to said working chambers, further comprising a control valve assembly with a first exit port and a second exit port, which are connected respectively to the first and the second connection of the first actuator, for controlling the movements of the first actuator. The control valve assembly comprises one or more operable control valves and is designed for selectively connecting one of the two or both exit ports thereof to the delivery port of the pump or the reservoir.

Abstract: The hydraulic control system disclosed herein employs a pair of combination poppet/spool valves to control the operation of a hydraulic cylinder driven from a bidirectional pump. Flow introduced through the source port of one valve lifts the poppet of the other valve on its way to one side of the cylinder which in turn opens a throttling port to modulate return flow from the other side of the cylinder.

Abstract: A hydraulic piston pump 1 includes a distributing valve 11 having a pair of arcuate or circular ports 11a and 11b formed through it. The arcuate port 11b is shorter circumferentially than the arcuate port 11a to reduce, by a predetermined amount, the amount of pressure oil to be discharged from and sucked into the pump through it. The valve 11 also has a pair of tank ports 11c and 11d formed through it circumferentially on both sides of the shorter port 11b. The circumferential dimensions of the tank ports 11c and 11d correspond to the predetermined amount of oil.

Abstract: A hydraulic system manifold having a body, a counterbalancer in the body and a flow controller in the body is disclosed. The body has first and second pump ports, first and second cylinder ports, first and second compensator ports and first and second supply conduits in communication with the first and second pump ports, the counterbalancer and the flow controller. The counterbalancer is in communication with the first and second supply conduits and the cylinder ports, to communicate hydraulic fluid between the first and second supply conduits and the first and second cylinder ports while counterbalancing hydraulic fluid pressure in the first and second supply conduits. The flow controller is in communication with the first and second supply conduits and the compensator ports, to control the flow of hydraulic fluid between the compensator ports and the first and second supply conduits to supply and store hydraulic fluid in a volumetric compensator in communication with the compensator ports.