Abstract: A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus and a piston that separates the piston chamber from the annulus. The hydraulic drive further includes a first hydraulic pump that has a pump intake and a pump outlet, a directional control valve that has a first and a second switching position, and a second hydraulic pump. The second hydraulic pump has a direction of delivery that is consistent with the direction of delivery of the first hydraulic pump at the pump outlet, wherein the second hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber and the second hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

Abstract: A hydraulic system for a machine is disclosed. The system may have a pump and a motor driven by pressurized fluid from the pump. An accumulator is configured to receive fluid discharged from the motor and to discharge fluid to the motor. The system may include a first valve to selectively communicate the higher pressure of conduits coupled between the pump and motor to the accumulator. A second valve and a third valve can be used to facilitate charging and discharging of the accumulator. The system may include a controller configured to implement a plurality of modes of operation, which each mode of operation may include a different combination of motor deceleration and motor acceleration segments during which the accumulator receives and discharges fluid, respectively. An input may be used to determine the segment of the work cycle.

Abstract: During boom-midair lowering operation in which a front work implement 130 can be turned under the self-weight of a boom 131, a hydraulic pump/motor 7 is operated as a motor to operate a generator/electric motor 10 as a generator. Power generation operation is performed by the hydraulic fluid discharged from a bottom-side chamber 5b of a boom cylinder 5 to recover positional energy. During jack-up in which the front work implement 130 cannot be turned under the self-weight of the boom 131, the generator/electric motor 10 is operated as an electric motor to operate the hydraulic pump/motor 7 as a pump. The jack-up is performed by supplying the hydraulic fluid from the bottom-side chamber 5b to rod-side chamber 5a of the boom cylinder 5 without supplying the hydraulic fluid from the main pump 2 to the rod-side chamber 5a of the boom cylinder 5.

Abstract: A hydraulic system is adapted to recover potential and kinetic energy of a work attachment of a work machine. A valve arrangement may configure the hydraulic system in various modes. The hydraulic system may provide suspension and/or actuation for the work attachment. The energy of the work attachment may move a rod of a first cylinder. The rod may pressurize fluid within the first cylinder. The pressurized fluid may flow from the first cylinder through a valve and into an accumulator. The first cylinder may amplify pressure of the fluid. The pressurized fluid in the accumulator may actuate the first cylinder. The movement of the rod of the first cylinder may cause simultaneous actuation of a second cylinder. A controller may monitor pressures and positions of components of the hydraulic system and control the valve arrangement.

Abstract: A hydraulic system for a working machine includes a hydraulic actuator and a first hydraulic machine for supplying fluid to the hydraulic actuator. The hydraulic system further includes a hydraulic transformer for supplying fluid to the hydraulic actuator in parallel with the first hydraulic machine, and an accumulator for fluid. The hydraulic transformer includes a first port and a second port and the transformer is adapted to transform a first pressure and a first flow at the first port to a second pressure and a second flow at the second port. The second port of the hydraulic transformer is in fluid communication with the hydraulic actuator and the first port is in communication with the accumulator.

Abstract: To provide construction machinery capable of more efficiently utilizing the energy of return hydraulic oil from a hydraulic actuator.

Abstract: An apparatus for transferring recovered power of a waste heat recovery unit (WHRU) includes a hydraulic pump converting the recovered power generated by an expander of the WHRU into a hydraulic energy; and a hydraulic motor converting the hydraulic energy converted by the hydraulic pump into rotational energy and transferring the rotational energy to a vehicle engine.

Abstract: A slide motion control apparatus for a mechanical press comprising: a slide which is disposed so as to be relatively vertically movable with respect to a driven body to which a drive force is transmitted through a con rod of the mechanical press; a relative position commander that outputs a relative position command indicating a relative position of the slide with respect to the driven body; a relative position detector that detects a relative position of the slide with respect to the driven body, and outputs a relative position detecting signal indicating the detected relative position; a servomotor; a drive mechanism that relatively moves the slide with respect to the driven body by a drive force of the servomotor; and a controller that controls the servomotor based on a relative position command signal output from the relative position commander, and the relative position detecting signal output from the relative position detector.

Abstract: An energy recovery system for a machine having a movable work tool, a swing motor to swing the work tool about a vertical axis, a pump providing pressurized fluid to the swing motor, a power source outputting power to drive the pump, and a controller. The energy recovery system may include a first accumulator, a swing charge valve selectively connecting the swing motor to the first accumulator, an assist motor operatively connected to the power source, and a discharge selectively connecting the first accumulator to the assist motor. The swing charge valve may fluidly connect the swing motor to the first accumulator when fluid pressure from the swing motor is greater than a charge set pressure. The controller may cause the discharge valve to fluidly connect the first accumulator with the assist motor when the power demand on the power source is greater than a minimum assisted power demand.

Abstract: A shuttle valve connects a second flowpath and a drain flowpath when the hydraulic pressure in a first flowpath is greater than the hydraulic pressure in the second flowpath. The shuttle valve connects the first flowpath and the drain flowpath when the hydraulic pressure in a second flowpath is greater than the hydraulic pressure in the first flowpath. The ratio between the pressure receiving area of a first pressure section and the pressure receiving area of a second pressure section is the same as the ratio between the pressure receiving area of a first chamber side and the pressure receiving area of a second chamber side of a cylinder rod.

Abstract: A booster device for a hydraulic circuit comprising a high-pressure circuit (12) and a low-pressure circuit (16) connected to a system generating the high pressure and to receivers, said booster device maintaining a minimum pressure in the low-pressure part, characterized in that it comprises a hydraulic motor (30) of which the inlet is connected to the high-pressure circuit (12) and the outlet to the low-pressure circuit (16), which drives a booster pump (20) sucking the fluid from a reservoir (24), in order to discharge it into this low-pressure circuit.

Abstract: The present invention relates to a closed hydraulic circuit between a hydraulic pump and a hydraulic motor that are connected to one another via working lines, a flushing pump being provided in order to feed a pressure medium into the working lines, and an output connection being provided in order to discharge excess pressure medium from the working lines. At least one hydraulic consumer, which is provided to convert at least some of the volume flow discharged from the hydraulic circuit into mechanical power, is connected downstream of the output connection.

Abstract: A hydraulic system is disclosed for assisting starting of a machine having an engine. The hydraulic system may include a work tool, a pump driven by the engine to pressurize fluid, and an actuator configured to receive pressurized fluid from the pump and move the work tool. The hydraulic system may also include an accumulator configured to selectively receive pressurized fluid from the pump and from the actuator, an electric starter configured to start the engine, and a motor selectively supplied with fluid from the accumulator to assist the electric starter in starting the engine.

Abstract: The present invention relates to a downhole tool, comprising a hydraulic assembly, an arm assembly, the arm assembly comprising a wheel, a hydraulic motor for rotating the wheel, thereby driving the downhole tool in a forward direction, and a hydraulic pump unit for simultaneous generation of a first and a second pressurized fluid, characterized in that the arm assembly is movable between a retracted position and a projecting position in relation to the tool housing, and the downhole tool furthermore comprises an arm activation assembly for moving the arm assembly between the retracted position and the projecting position, and the hydraulic motor drives the downhole tool in the forward direction when the arm assembly is in the projecting position, the arm activation assembly being in fluid connection with the first pressurized fluid and the hydraulic motor being in fluid connection with the second pressurized fluid, a hydraulic control block for controlling the pressure of the first pressurized fluid having a

Abstract: A hydraulic system powered by a shaft of an engine to control a plurality of hydraulic cylinders including at least one boom lift hydraulic cylinder coupled to a boom to pivot the boom about a horizontal axis, wherein a first variable displacement pump/motor and a second variable displacement pump/motor can be connected to provide a higher flow to the at least one boom lift hydraulic cylinder than a flow achieved by one of the first variable displacement pump/motor or the second variable displacement pump/motor, and a high-pressure accumulator and the first variable displacement pump/motor and the second variable displacement pump/motor can add power back to the engine shaft.

Abstract: An electric hydraulic motor system for vehicles features an electric motor and an electric generator operatively connected to a battery of a vehicle and hydrogen fuel cell. The system features a fuel engine hydraulic pump operatively connected to a standard fuel engine of the vehicle. The system features a hydraulic reservoir operatively connected to the fuel engine hydraulic pump. The system features a first hydraulic pump operatively connected to each the electric motor and the hydraulic reservoir. The system features a first hydraulic motor operatively connected to each the hydraulic reservoir, and wheels of the vehicle. The system features a second hydraulic motor operatively connected to each the electric generator and the hydraulic reservoir. The system features a second hydraulic pump operatively connected to each the wheels of the vehicle and the hydraulic reservoir.

Abstract: A shovel includes a plurality of hydraulic actuators including a first hydraulic actuator and a second hydraulic actuator, a main pump, a hydraulic pump-motor configured to function as a hydraulic motor by using hydraulic oil flowing out of the first hydraulic actuator and configured to function as a hydraulic pump, a control valve configured to control a flow of the hydraulic oil in the plurality of hydraulic actuators, a first oil passage to connect the main pump with the second hydraulic actuator through the control valve, and a second oil passage to connect the hydraulic pump-motor with the second hydraulic actuator. The second oil passage meets the first oil passage between the control valve and the second actuator.

Abstract: A hydraulic motor (52) is arranged in a control hydraulic line (51) connecting a second hydraulic fluid supply line (4a) (for supplying the hydraulic fluid delivered from the main pump (2) to flow control valves (26a to 26h)) to a tank (T). A generator (53) connected with the rotating shaft (52a) of the hydraulic motor (52). Maximum load pressure (PLmax) is detected by a pressure sensor (54). Power generation control of the generator (53) is performed by a second control device (55) so that the hydraulic motor (52) rotates when the delivery pressure of the main pump (2) exceeds target control pressure (Pun) determined by adding a preset value (Pb) to the maximum load pressure (PLmax). AC power generated by the generator (53) is stored in a battery (41).

Abstract: A hydrostatic driveline is provided. The hydrostatic driveline comprises a power source, a hydrostatic pump, a hydrostatic motor, a direct drive link, and a transmission portion. The power source is drivingly engaged with an input member. The hydrostatic pump is in driving engagement with the input member. The hydrostatic motor is in fluid communication with the hydrostatic pump. The direct drive link is in driving engagement with the input member. The transmission portion is in driving engagement with a vehicle output and at least one of the hydrostatic motor and the direct drive link The transmission portion includes at least one engagement device and a drive ratio. The hydrostatic pump, the hydrostatic motor, and the transmission portion form a first power path for the hydrostatic driveline and the direct drive link forms a second power path for the hydrostatic driveline.

Abstract: Disclosed is a hydraulic system for a hydraulic excavator. The hydraulic system inputs rotary power from a rotary power producing means to a hydraulic pump to produce hydraulic power, and operates an actuator by the hydraulic power. A hydraulic oil drain line from the actuator is branched into a flow rate control line as a line connected to a spool of a flow rate control valve controllable by manipulation of a lever and a power regeneration line as a line connected to a variable displacement motor for converting hydraulic power of discharged hydraulic oil to reusable energy. A regeneration ratio control means is also arranged to control the variable displacement motor such that a flow rate of the power regeneration line satisfies a preset fixed ratio ? relative to a flow rate occurred in the flow rate control line by the manipulation of the lever.

Abstract: An energy regeneration type forklift hydraulic system is provided, which includes a first oil pump, a first electrical motor, a multiple directional control valve, a lifting oil cylinder, a tilting oil cylinder, a steering oil cylinder, a load-sensing steering device, an oil filter, a second oil pump and an oil tank, wherein the multiple directional control valve includes an oil inletting and returning valve spool, a raising and lowering reversing valve spool, a tilting reversing valve spool, and an oil inletting valve spool. The raising and lowering reversing valve spool includes a raising and lowering three-position six-way reversing valve, an annular oil returning passage and an oil returning passage. The system can utilize the potential energy of lowering cargo to simultaneously drive two oil pumps for driving two motors to generate energy, thereby realizing energy recovery.

Abstract: A hydraulic system is adapted to recover potential and kinetic energy of a work attachment of a work machine. A valve arrangement may configure the hydraulic system in various modes. The hydraulic system may provide suspension and/or actuation for the work attachment. The energy of the work attachment may move a rod of a first cylinder. The rod may pressurize fluid within the first cylinder. The pressurized fluid may flow from the first cylinder through a valve and into an accumulator. The first cylinder may amplify pressure of the fluid. The pressurized fluid in the accumulator may actuate the first cylinder. The movement of the rod of the first cylinder may cause simultaneous actuation of a second cylinder. A controller may monitor pressures and positions of components of the hydraulic system and control the valve arrangement.

Abstract: A shovel according to an embodiment of the present invention is a shovel including a boom cylinder and an arm cylinder. The shovel includes a hydraulic motor driven by hydraulic oil flowing out of the boom cylinder, a regenerating oil passage configured to supply the hydraulic oil flowing out of the boom cylinder to the hydraulic motor, a reusing oil passage configured to supply the hydraulic oil flowing out of the boom cylinder to the arm cylinder, and a reusing flow control valve configured to control a flow rate of hydraulic oil flowing in the reusing oil passage.

Abstract: To achieve flow demands for high flow services, a hydraulic system shares a flow between a hydraulic transformer and one or more hydraulic pumps. The hydraulic transformer is in selective fluid communication with the pumps and actuates a first load. A second load is driven by an actuator in selective fluid communication with the pumps and the hydraulic transformer. The hydraulic system includes a controller to reduce dynamic responses in the system by causing flow sharing between the hydraulic transformer and a directional flow control valve.

Abstract: A construction machine, including: a hydraulic pump; a working attachment including a boom, a boom cylinder, and another fluid-supplied cylinder closer to a leading end than the boom cylinder; first and second operation devices for the boom cylinder and the fluid-supplied cylinder; first and second control valves; a flow-rate-limiting section; and an anti-cavitation circuit. The fluid-supplied cylinder receives fluid-supply from the hydraulic pump, together with the boom cylinder. A reaction force upon work accompanying extension of the fluid-supplied cylinder increases the rod-side pressure of the boom cylinder and reduces a head-side pressure. The flow-rate-limiting section limits a supply flow rate to a head-side fluid chamber of the boom cylinder only during a boom-raising-operation with the rod-side pressure higher than the head-side pressure in the boom cylinder. The anti-cavitation circuit replenishes hydraulic fluid from a tank to the head-side fluid chamber.

Abstract: Methods and systems are provided for reducing turbo lag in a boosted engine. A boost reservoir coupled to the engine may be charged with compressed intake air and/or combusted exhaust gas. The pressurized charge may then be discharged during a tip-in to either the intake or the exhaust manifold.

Abstract: A hydraulic hybrid system for implementation in a machine. The system includes a hydraulic system, an energy source, an output, and a transmission. The hydraulic system includes a primary hydraulic pump/motor (primary motor) that is hydraulically coupled to a reservoir and a variable-volume accumulator assembly. The primary motor is configured to charge an accumulator of the variable-volume accumulator assembly with a working fluid when mechanically driven. The storage volume of variable-volume accumulator assembly varies based on a kinetic output condition of the machine. The energy source is configured to produce primary kinetic energy. The output is configured to receive at least a first portion of the primary kinetic energy. The transmission is coupled between the energy source and the output and selectively coupled to the primary motor. The transmission is configured to mechanically drive the primary motor using a second portion of the primary kinetic energy.

Abstract: A forklift (1) according to the present invention includes: an engine (7); a hydraulically-operated device for cargo handling (2); a pump for cargo handling (5) that is driven by the engine (7); hydraulic piping for cargo handling (8) that connects the pump for cargo handling (5) and the hydraulically-operated device for cargo handling (2); discharge piping (110) that branches from the hydraulic piping for cargo handling (8) and is connected to a tank (4); a switching valve (111) capable of switching the opening and closing of the discharge piping (110); a control device (13) that closes the discharge piping (110) when the rotation speed of the engine (7) is larger than a predetermined value, and opens the discharge piping (110) when the rotation speed of the engine (7) is less than or equal to a predetermined value; and a sub-relief valve (112) that adjusts the flow rate of hydraulic oil that is discharged from the discharge piping (110) to the tank (4), on the bases of the pressure or the flow rate of the h

Abstract: An energy recovery control circuit is provided with an energy recovery system for recovering energy of a work equipment. The energy recovery control circuit includes an recovery control valve block in which a plurality of valves that constitute the energy recovery system are incorporated. The recovery control valve block includes a main spool, in which a plurality of control characteristics concerning recovery of energy are consolidated.

Abstract: An energy recovery system for a machine is disclosed. The energy recovery system may have a boom circuit with at least a one linear actuator configured to move a work tool, and a boom accumulator configured to selectively collect pressurized fluid from the at least one linear actuator and to discharge pressurized fluid back to the at least one linear actuator. The energy recovery system may also have a swing circuit with a swing motor configured to move the work tool, and a swing accumulator configured to selectively collect pressurized fluid from the swing motor and discharge pressurized fluid back to the swing motor. The energy recovery system may further have a common accumulator passage fluidly connecting the boom accumulator and the swing accumulator.

Abstract: A power regeneration device for an operating machine has a hydraulic cylinder and a return line through which fluid returning to a tank flows when the hydraulic cylinder contracts. The return line branches into a plurality of hydraulic lines through a branching part and includes a regeneration line that which leads returning fluid to the tank via a hydraulic motor to which a generator is connected. A control valve line is connected to the branching part and leads the returning fluid to the tank via a control valve. An electricity storage device stores electric power generated by the generator, and an electric amount detector detects the electric amount of the electricity storage device. A flow rate calculator calculates the flow rate of the returning fluid flowing through the regeneration line and the flow rate of the returning fluid flowing through the control valve line depending on an electric amount signal.

Abstract: A control system for construction machine includes a main pump; a circuit system which includes a plurality of operation valves; a boom cylinder which is connected to a specific valve; one passage which allows communication between the specific operation valve and a piston-side chamber; another passage which allows communication between the specific operation valve and a rod-side chamber; a hydraulic motor which rotates by the action of return oil from the piston-side chamber; a generator; and a valve mechanism which is provided in the one passage communicating with the piston-side chamber of the boom cylinder, introduces the return oil from the piston-side at the time of descent as a regeneration flow to the hydraulic motor and introduces the return oil as a recovery flow to the rod-side chamber if necessary by causing the return oil to flow into the other passage.

Abstract: A folding implement frame having seven sections in a use position and nine sections when folded. The frame design allows a frame having a width of greater than 27 meters to be folded into a transport position having a width of less than eight meters and a height of less than six meters. The hydraulic system transfers weight to the center frame section during folding and unfolding to enhance stability. The hydraulic system uses accumulators to minimize the amount of oil reduction in the tractor reservoir resulting from extension of the hydraulic cylinders of the implement. Implement raise and lower cycle times are minimized by a helper cylinder to lift the frame main section when the entire implement weight is on the main section and allowing a smaller cylinder to lift the frame main section in the use position for shorter cycle times to raise and lower the implement.

Abstract: The present invention relates to a working device having an element movable via at least one working cylinder, with at least one energy recovery cylinder being provided for recovering energy from the movement of the movable element and having a chamber filled with gas. In this respect, the chamber filled with gas is in operative communication with a pressure store which counters a pressure increase in the chamber filled with gas at least from a maximum pressure onward.

Abstract: A hydraulic system is disclosed. The hydraulic system may have a pump with variable-displacement, a first linear actuator, and a second linear actuator coupled to the first linear actuator to operate in tandem. The first and second linear actuators may be connected to the pump in closed-loop manner, and each of the first and second linear actuators may have a first chamber and a second chamber separated by a piston. The hydraulic system may also have an accumulator in fluid communication with the second chamber of only the second linear actuator.

Abstract: A hydraulic arrangement includes at least one pressure unit connected to a hydraulic machine that is operable as a pump and a safety device for the pressure unit. The safety device includes pressure sensors configured to detect a pressure in the pressure unit and an electronic control unit that is connected to the pressure sensors. A delivery volume pumped by the hydraulic machine is configured to be controlled via the control unit.

Abstract: A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a tank, a pump, a swing motor, and at least one control valve configured to control fluid flow between the pump, the swing motor, and the tank. The hydraulic system may also have an accumulator configured to selectively receive pressurized fluid discharged from the swing motor and selectively supply pressurized fluid to the swing motor, at least one accumulator valve, and a controller. The controller may be configured to receive input indicative of a difference between desired and actual speeds of the swing motor, and determine if the swing motor is accelerating or decelerating based on the difference. The controller may also be configured to control the at least one accumulator valve to cause the accumulator to selectively receive or supply pressurized fluid only when the swing motor is accelerating or decelerating.

Abstract: A method and system for accumulating and using recovered hydraulic energy that includes a hydraulic actuator and a pump configured to supply pressurized fluid to the hydraulic actuator. An energy recovery system includes a hydraulic motor, a charge valve and an accumulator configured to store fluid from the hydraulic actuator. The charge valve is operatively connected between the hydraulic actuator and the accumulator and between the accumulator and the hydraulic motor and is configured to place the hydraulic actuator in fluid communication with the accumulator and to place the accumulator in fluid communication with the hydraulic motor. A directional valve is operatively connected between the pump and the hydraulic actuator. The directional valve is configured to place the pump in fluid communication with the hydraulic actuator and to direct the flow of hydraulic fluid exiting the hydraulic actuator to the charge valve in an energy recovery mode.

Abstract: A hydraulic system is disclosed that has first and second passages connecting a pump to an actuator in closed-loop manner, and first and second load-holding valves within the first and second passages. The hydraulic system may also have a regeneration valve connected to the first and second passages between the actuator and the first and second load-holding valves to selectively connect the first and second passages. The hydraulic system may further have a controller configured to cause a control valve to simultaneous move the first and second load-holding valves toward flow-blocking positions when pump displacement is about zero. The controller may also be configured to selectively cause the regeneration valve to connect the first and second passages when pump displacement is non-zero, and to cause only one of the first and second load-holding valves to move to its flow-blocking position when the regeneration valve connects the first and second passages.

Abstract: A power control apparatus and method according to a load of a hybrid excavator including an H-ECU is disclosed. If a difference between an actual power value actually used in a load (SW PEC and ISAM PEC) or in an ESS and a power value required for an actual use in the load is equal to or larger than a set error value, a power that is supplied from the ESS to the PECs and a power that is supplied between the PECs are controlled to be cut off, and thus high voltage is prevented from being continuously supplied to circuits to thereby prevent secondary problems (e.g., fire, trouble of equipment, and the like) from occurring due to the high voltage.

Abstract: Hydraulic unit adapted for connection to master and slave actuator system includes three valves, the first configured for selective fluid passage between the cap ends, the second configured for selective fluid passage between the slave cap end and an accumulator, and the third fluidly coupled for selective fluid passage between each of a single pump and the accumulator, and the slave cap end. During actuator retraction, the valves permit pressurized fluid in the slave cap end to be delivered to accumulator for storage; during extension, the valves permit pressurized fluid from pump and accumulator to be delivered to the slave cap end.

Abstract: A shut off valve is configured to shut off flow from the high pressure fluid line to the high pressure accumulator in a series hydraulic hybrid vehicle in order to quickly raise system pressure in the high pressure fluid line and enable additional torque output from the hydraulic motor for vehicle propulsion. A pressure relief valve is further provided to vent excess flow from the high pressure line to the high pressure accumulator as needed to avoid exceeding a maximum desired system pressure in the high pressure fluid line, thereby providing for safe and efficient hydrostatic operation in the vehicle.

Abstract: A controller determines whether or not a control valve for controlling the supply of pressure fluid from a main pump to an actuator is at a neutral position, detects input power of a hydraulic motor rotated by return oil from the actuator, and narrows the opening of a proportional electromagnetic throttle valve when the control valve is at the neutral position and the input power of the hydraulic motor is in excess of a first threshold value.

Abstract: Hydraulically driven arrangement for the linear movement of a mass body consisting of two double acting cylinders coupled in parallel, whereby one operating cylinder is a control cylinder for controlling the movement of the mass body, which is split into an acceleration phase, a movement phase and a brake phase. The other operating cylinder is connected as a drive cylinder to the hydraulic power pack as an energy storage, in a manner that the power pack during the acceleration phase of the mass body generates the drive energy for the drive cylinder, and the drive cylinder in the brake phase of the mass body, which serves as a pump for charging the hydraulic power pack. The control cylinder and drive cylinder each have a piston with a one-sided piston rod coupled to the mass body. The control cylinder and the drive cylinder are controlled by hydraulically separated, independent control circuits.

Abstract: Provided is a hybrid construction machine including: a hydraulic actuator; a hydraulic pump which discharges hydraulic fluid for driving the hydraulic actuator; a generator-motor which performs an electric generator action of generating electric power and an electric motor action of generating motive power; an engine connected to the hydraulic pump and the motor-generator; an electrical storage device; and a controller which causes the generator-motor to perform the electric generator action and charge the electrical storage device and causes the generator-motor to perform the electric motor action by electric power discharged from the electrical storage device to assist the engine. The controller causes the generator-motor to start the electric generator action when an engine output becomes equal to or greater than a predetermined engine lower limit output, and controls the electric generator action to keep the engine output no lower than the engine lower limit output.

Abstract: A support for supporting a structure on a surface, comprising at least one support element, each support element comprising a piston, a cylinder in which the piston is moveable, and a brake for maintaining the piston in a position that is stable relative to the cylinder, wherein the piston and the cylinder are arranged so that a loading associated with the structure effects an adjustment of the support element, and wherein an increase in hydraulic pressure within the cylinder, effected by the loading associated with the structure, activates the brake.

Abstract: A machine includes a hydraulic cylinder configured to raise and lower a boom of the machine, and an accumulator selectively fluidly connected to the hydraulic cylinder. The accumulator is configured to receive fluid from the hydraulic cylinder during lowering of the boom. The machine also includes a hydraulic motor fluidly connected to the accumulator via an independent metering valve. The machine further includes a fan driven by the hydraulic motor and configured to assist in cooling fluid displaced from the hydraulic cylinder.

Abstract: To lower the fuel consumption of a vehicle having a pneumatic brake system during operation of the vehicle by utilizing existing components to their full capacity, thus contributing to energy conservation, a method and device for controlling pressure is provided, wherein modes of compressed air expansion are provided. In a second compressed-air expansion mode, compressed air is channeled from a second compressed-air storage container to the compression chamber of the air compressor during expansion phases of the air compressor. In a third compressed-air expansion mode, compressed air is channeled from a third compressed-air storage container to the compression chamber of the air compressor during expansion phases of the air compressor.

Abstract: An energy regeneration type forklift hydraulic system is provided, which includes a first oil pump, a first electrical motor, a multiple directional control valve, a lifting oil cylinder, a tilting oil cylinder, a steering oil cylinder, a load-sensing steering device, an oil filter, a second oil pump and an oil tank, wherein the multiple directional control valve includes an oil inletting and returning valve spool, a raising and lowering reversing valve spool, a tilting reversing valve spool, and an oil inletting valve spool. The raising and lowering reversing valve spool includes a raising and lowering three-position six-way reversing valve, an annular oil returning passage and an oil returning passage. The system can utilize the potential energy of lowering cargo to simultaneously drive two oil pumps for driving two motors to generate energy, thereby realizing energy recovery.

Abstract: A hydrostatic drive system has a motor-driven hydraulic pump (1) connected to at least one hydraulic drive unit (7) by a first working line (19) and a second working line (21) forming a hydraulic circuit. The drive unit is connected to a gear set (1, 3). A first hydraulic accumulator (53) for accumulating pressure energy can be connected to one of the working lines (19, 21). A second hydraulic accumulator (55) can be connected to the other working line (19, 21). A valve device (V1, V2) permits the segment (23, 25) of each working line (19 or 21) extending to the drive unit (7) to be separated to separate an accumulator part (33) from the part of the circuit with the hydraulic pump (13). The accumulator part includes the hydraulic accumulators (53, 55) and at least one drive unit.