Abstract: A power distribution system includes a prime mover and a hydraulic drive system. The hydraulic drive system includes an accumulator to store energy and supplement that available from the prime mover. A control monitors torque imposed on the prime mover and utilizes energy stored in the accumulator to offload the prime mover when its operating conditions are to be changed. Effecting a change under reduced load conditions mitigates inefficient operation of the prime mover.

Abstract: An improvement is provided to a pressurized close-cycle machine that has a cold-end pressure vessel and is of the type having a piston undergoing reciprocating linear motion within a cylinder containing a working fluid heated by conduction through a heater head by heat from an external thermal source. The improvement includes a heat exchanger for cooling the working fluid, where the heat exchanger is disposed within the cold-end pressure vessel. The heater head may be directly coupled to the cold-end pressure vessel by welding or other methods. A coolant tube is used to convey coolant through the heat exchanger.

Abstract: A hydraulic drive system for driving a load includes a drive shaft; first and second hydraulic pumps driven by the drive shaft, and a control system that operates the hydraulic drive system in a plurality of modes including: a) a first mode where the second hydraulic pump pumps hydraulic fluid from a supply line to an accumulator; b) a second mode where the second hydraulic pump pumps hydraulic fluid from the accumulator to the supply line; c) a third mode where the second hydraulic pump pumps hydraulic fluid from the supply line to a reservoir; and d) a fourth mode where the second hydraulic pump pumps hydraulic fluid from the reservoir to the supply line. At least the second hydraulic pump is a variable displacement bidirectional pump.

Abstract: A hydraulic actuator includes an energy recuperation device which harvests the energy generated from the stroking of a shock absorber. The energy recuperation device can function in a passive energy recovery mode for the shock absorber or an active mode for the shock absorber. The energy that is generated by the energy recuperation device can be stored as fluid pressure or it can be converted to another form of energy such as electrical energy.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A hydraulic circuit is disclosed. The hydraulic circuit may have a pump, a motor, a tank, and an accumulator. The hydraulic circuit may also have a valve movable between a first position at which an output of the pump is fluidly connected to the tank and the accumulator is fluidly connected to the motor, and a second position at which the output of the pump is fluidly connected to the motor.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: In various embodiments, a mechanical assembly and/or storage vessel is fluidly coupled to a circulation apparatus for receiving pressurized heat-transfer fluid from an outlet at a first elevated pressure, boosting a pressure of the heat-transfer fluid to a second pressure larger than the first pressure, and returning heat-transfer fluid to an inlet at a third pressure.

Abstract: A system for reversible storage of energy, the system comprising: means for generating energy; first conversion means for converting the energy into stored energy by means of low ratio (3.2:1 or less) high pressure (200 bar minimum) compression of gas; and second conversion means for converting the stored energy by expansion or reversal of the first process into usable energy.

Abstract: The invention relates to systems and methods for rapidly and isothermally expanding and compressing gas in energy storage and recovery systems that use open-air hydraulic-pneumatic cylinder assemblies, such as an accumulator and an intensifier in communication with a high-pressure gas storage reservoir on a gas-side of the circuits and a combination fluid motor/pump, coupled to a combination electric generator/motor on the fluid side of the circuits. The systems use heat transfer subsystems in communication with at least one of the cylinder assemblies or reservoir to thermally condition the gas being expanded or compressed.

Abstract: A hydraulic supply device of an automatic transmission, which supplies operating oil to the automatic transmission that is able to shift power from an engine and transmit the power to drive wheels of a vehicle by selectively engaging a plurality of frictional engagement devices using hydraulic pressure is disclosed.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: In various embodiments, efficiency of energy storage and recovery systems compressing and expanding gas is improved via heat exchange between the gas and a heat-transfer fluid.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A hydraulic system including a hydraulic power source (102) having an output and a directional control valve (106) coupled to the output of the hydraulic power source. The system also includes a hydraulic cylinder (108) coupled to the directional control valve that receives hydraulic fluid at a first port and expels it at a second port as it moves a load (114) at a movement rate, a fixed displacement motor (150) coupled the directional control valve and receiving hydraulic fluid expelled by the hydraulic cylinder and a variable displacement pump (154) attached to a drive arm (152) of the motor.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: An air compressor includes a compression unit, a drive unit, a tank unit, and a control circuit unit. The compression unit is configured to generate a compressed air and provided with a handle positioned above a center of gravity of the air compressor. The drive unit is configured to drive the compression unit. The tank unit is disposed below the compression unit and includes a plurality of air tanks configured to reserve the compressed air. The compressed air reserved in the tank unit has a pressure value. The control circuit unit is configured to detect the pressure value of the compressed air reserved in the tank unit and to control the drive unit to drive the compression unit.

Abstract: In various embodiments, a mechanical assembly and/or storage vessel is fluidly coupled to a circulation apparatus for receiving pressurized heat-transfer fluid from an outlet at a first elevated pressure, boosting a pressure of the heat-transfer fluid to a second pressure larger than the first pressure, and returning heat-transfer fluid to an inlet at a third pressure.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A hydraulic control device for moving at least one hydraulic consumer comprises at least one supply line, a discharge line or bypass line to which the hydraulic consumer is connected, and at least one pressure source and, optionally, a directional control valve. The line contains a dosing device for measuring a hydraulic medium dose by using a given compressibility of the hydraulic medium. The measured hydraulic medium dose either is supplied from the dosing device into the hydraulic consumer connected downstream or is discharged from the hydraulic consumer connected upstream into the dosing device. The dosing device comprises from upstream to downstream in series first and second blocking members which respectively can be switched into a leakage-free blocking position and into a through flow position, and a dead space between the blocking members. For dosing the hydraulic medium dose the blocking members are switched several times alternatingly.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: The invention relates to a mobile hydraulic system for a hybrid vehicle, comprising a hydraulic accumulator device (22), which comprises a high-pressure accumulator chamber (34) and a low-pressure accumulator chamber (35), between which a hydraulic drive unit is connected, wherein the hydraulic drive unit is used to convey an incompressible fluid from the low-pressure accumulator chamber (35) into the high-pressure accumulator chamber (34) in an accumulator operating state, wherein the incompressible fluid can be discharged from the high-pressure accumulator chamber into the low-pressure accumulator chamber (35) in a drive operating state in order to hydraulically drive the hydraulic drive unit.

Abstract: A hydraulic control system for actuating at least one torque transmitting device in a transmission includes a sump, a pump in communication with the sump, and an accumulator. A first control device and a second control device control the communication of hydraulic fluid between the pump, the accumulator, and the torque transmitting device.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A hydraulic system has a valve assembly with two workports coupled to chambers of first and second cylinders which are connected mechanically in parallel to a machine component. A separation control valve is connected between first chambers of both cylinders, and a shunt control valve is connected between the workports. A recovery control valve couples an accumulator to the first chamber of the second cylinder. Opening and closing the valves in different combinations routes fluid from one or both cylinders into the accumulator where the fluid is stored under pressure, and thereafter enables stored fluid to be used to power one or both cylinders. The shunt control valve is used to route fluid exhausting from one chamber of each cylinder to the other chambers of those cylinders. Thus the hydraulic system recovers and reuses energy in various manners.

Abstract: The invention provides methods and systems for starting auxiliary systems, comprising an auxiliary pump system having: a) a motorpump assembly having a constant displacement pump coupled to an electric motor; b) a hydraulic accumulator in fluid communication with said motorpump assembly; and c) lines to at least on auxiliary system in fluid communication with said motorpump assembly.

Abstract: A block manifold for a fail safe actuator system allows the actuator operation with a hand pump if electrical power were not available. A method is available to isolate fail safe solenoid valves and an accumulator from a hand pump circuit to relieve the stored energy from the fail safe circuit. An additional set of pilot operated check valves were installed between the motor driven pump circuit and the hand pump circuit. These pilot operated check valves isolated the hand pump circuit from the fail safe dump solenoid and accumulator. These pilot actuated check valves also hold the actuator in the fail safe position as long as the hand pump system was not used. There is also a hydraulic bleed circuit to relieve the accumulator stored energy when the hand pump system was used.

Abstract: In an electrohydraulic drawing press drive, particularly an electrohydraulic drawing cushion drive including a hydraulic circuit with at least one motor which is operable as a drive motor or as a pump and at least one hydraulic pump which is operable as a pump or as a drive motor, an electric drive motor which is also operable as generator is connected to the hydraulic motor in order to drive the hydraulic motor or to be driven thereby and a control unit is provided for controlling at least one of the electric motor and the hydraulic pump.

Abstract: Construction machinery which is capable of improving fuel efficiency of the engine and also capable of effectively utilizing surplus energy in a light-load mode. The construction machinery includes an engine, a hydraulic pump driven by the engine, and actuators driven by oil pressure supplied from the hydraulic pump. In the light-load mode where the engine torque at the intersection point of an iso-horsepower curve of the necessary horsepower and a governor characteristic curve of the engine is smaller than that of a rated output point of the engine, the number of revolutions of the engine is reduced while the engine torque is increased with respect to the intersection point, and the horsepower is made to exceed the iso-horsepower curve. With surplus torque generated therefrom, a power generator is operated so as to generate electric power, which is stored in a power accumulation apparatus.

Abstract: Disclosed is an actuator system for positioning a piston within a cylinder and comprising a compressed air source, a positioner, and first and second pneumatic valving modules. The first and second pneumatic valving modules respectively comprise first and second volume boosters to amplify the flow of compressed air, first and second derivative boosters to alternately supply and exhaust compressed air into and out of the first and second ends at high flow rates, and first and second commutators to selectively allow the compressed air to flow respectively between the volume boosters and the derivative boosters. A safety valve opens at a predetermined pressurization level such that the first and second commutators may be energized. A volume tank provides compressed air to each one of the first and second pneumatic valving modules upon energization of the first and second commutators.

Abstract: A reciprocating drive system that utilizes energy available from pressure changes in flowing fluid systems, said drive used for the injection of additives into pipelines. The reciprocating drive includes a hydraulic accumulator having a gas chamber connected to a gas pipeline to contain said gas, whereby variation in the elevated pressure of the pipeline is reflected in the pressure applied to an incompressible fluid in a hydraulic conduit. The drive is capable of recycling gas used to drive the system back into pipelines.

Abstract: A method is provided for attenuating noise in a hydraulic circuit having a pump in fluid communication with a hydraulic actuator by a conduit. The method includes supplying a flow restricting device in the conduit and generating a signal representative of a fluid fluctuation in the conduit downstream of the flow restricting device. A bypass loop is provided in parallel with the flow restricting device and the bypass has a valve. The valve is controlled based on the generated signal to generate a corrective fluid flow to attenuate the noise.

Abstract: The invention relates to a hydraulic steering system architecture comprising at least one steering control actuator having chambers connected to the outlets of a directional-control valve, an accumulator, and an electrically-driven pump unit associated with an emergency supply. The hydraulic system also comprises a general selector arranged, in a normal mode of operation, to connect the feed port of the directional-control valve to a pressure-generator device and the return port of the directional-control valve to a main supply associated with the pressure-generator device, while also ensuring that the emergency supply is filled, and in an alternate mode of operation, to connect the feed port of the directional-control valve to the accumulator.

Abstract: Compact, low-cost construction equipment capable of effectively recovering energy from a plurality of hydraulic actuators is provided. To this end, the construction equipment comprises: a hydraulic recovery circuit for recovering return oil from the hydraulic actuators, the circuit being equipped with a pump motor rotatably driven by the recovered return oil; oil guide passages each of which is for guiding return oil from the meter-out side of its corresponding hydraulic actuator to the hydraulic recovery circuit; switches for switching the respective oil guide passages between their opened and closed states; pressure sensors for detecting the back pressure of each hydraulic pressure actuator; and a dynamo-electric generator for generating electric power from the rotary force of the pump motor.

Abstract: In a braking pressure intensifying master cylinder of the present invention, as an input shaft 53 travels forwards in a braking maneuver, a control valve 54 is actuated to develop fluid pressure according to the input in a reaction chamber 38 and a pressurized chamber 35. A stepped spool 45 as a part of the control valve 54 travels such that force produced by the fluid pressure and spring force of a spring 51 are balanced, whereby the stepped spool 45 can function as a travel simulator. By changing the pressure receiving areas of the stepped spool 45 and/or changing the spring force of the spring 51, the travel characteristic of the input shaft 53 as the input side can be freely changed independently from the output side, without influence on MCY pressure as the output side of the braking pressure intensifying MCY 1. In addition, the master cylinder pressure can be intensified when necessary with a simple structure.

Abstract: Energy of returning pressurized fluid of an actuator is recovered and reused as energy for operating other accumulators. A first pump motor (16) and a second pump motor (17) are mechanically connected to form a pressure converter (18), and a first circuit (22), to which the returning pressurized fluid is supplied, is connected to the first pump motor (16). A pressure accumulator (27) is provided to a second circuit (25) connected to the second pump motor (17). The first circuit (22) is connected to a discharge passage (11) of a primary hydraulic pump (10) by a third circuit (29) and the pressure of a high pressure pressurized fluid is supplied to the discharge passage (11) by the pressure of the high pressure pressurized fluid, and is reused.

Abstract: A hydraulic control arrangement for a mobile working machine has at least one hydraulic cylinder with the aid of which a working tool is moved, a directional control valve for controlling pressure-fluid channels between chambers of the hydraulic cylinder, a pressure-fluid source and a tank, a hydraulic accumulator connected to the pressure-fluid source via a filling line, and a control valve to open and to close a connection between the hydraulic accumulator and a pressure chamber of the hydraulic cylinder. To achieve a damping of pitching movement of the machine, a pilot-operated shutoff valve is connected upstream of the pressure chamber of the hydraulic cylinder, and opens when the directional control valve is actuated to allow pressure fluid to flow off from the pressure chamber to the tank.

Abstract: A fluid path opening/closing valve comprises a plate-like valve plug and a rack which is fixed to a piston of an emergency shut-down air cylinder. The rack meshes with a pinion which rotates by a reversible motor with a clutch. If a seismic detecting valve detects earthquake which has over predetermined seismic intensity and opens, compressed air is sent from an air tank via the opened seismic detecting valve to a switching cylinder which disconnects the clutch. At the same time, compressed air is sent from the air tank to the emergency shut-down air cylinder via a delay valve to lower the piston with the fluid-path opening/closing valve which closes the fluid path.

Abstract: A pneumatic piston-cylinder apparatus of single acting type which performs a working stroke in one working direction, and is returned to its initial position without any external supply of compressed air comprising a cylinder part with cylinder jacket (1), a front end (2), a rear end (3), and a piston (5) which is reciprocatable in the cylinder. Connected to the rear end (3) is a supply of compressed air and within the cylinder is a return channel (10) used for draining the air on the unloading side of the piston.