Abstract: The present disclosure shows a hydraulic regeneration circuit for a hydraulic cylinder that enables multiple extension speeds for the cylinder even while using fixed displacement pumps. The regeneration circuit uses the expelled fluid to drive a hydraulic pump/motor combination to create 4 or more speeds, as opposed to the 2 speeds typical in regeneration circuits. By using directional flow control valves, the fluid can be combined in such a way that the operator can choose a speed multiplier for the hydraulic cylinder to operate at.

Abstract: An energy storage system includes a pneumatic vessel, a cable system attached to the vessel, a compressor for pressurizing the vessel, a generator attached to the cable system, a turboexpander generator for receiving compressed air from the vessel, and a control system. The system deflates and allows the vessel to sink in a body of water, inflates the vessel to store energy when an abundance of it exists, and allows the inflated vessel to resurface to release its buoyant energy to the generator via the cable system and to release compressed air to the turboexpander generator to generate electricity when electricity demand is high and/or electricity generation from other sources is low.

Abstract: To put new thought to a control method, and to obtain good operability, upon providing a control circuit for option hydraulic actuator in a hydraulic circuit for a working machine. There is provided an option merging oil passage that allows the discharge oil of the first, second hydraulic pumps to be merged thereinto, and the option merging oil passage is provided with an option control valve and a compensator valve, and is configured such that a variable relief valve is connected to a signal pressure introduction oil passage connected to the compensator valve, a supply pressure to an option hydraulic actuator can be variably controlled by changing a relief setting pressure of the variable relief valve; on the other hand, distributed flow rate computation with respect to the other hydraulic actuators, opening area control of the option control valve, the other hydraulic actuators control valves, and discharge pressure control of the first, second hydraulic pumps are optimized.

Abstract: A pneumatic device having a pneumatic cylinder and a piston movably mounted in the pneumatic cylinder to divide an interior of the pneumatic cylinder into two chambers. The chambers are connected to a line network having a valve assembly. The line network, in a plurality of operating states of the valve assembly serving for venting the respective chamber, connects the respective chamber to at least a respective selected one of a plurality of outflow openings, of the pneumatic device, and in a further operating state of the valve assembly, disconnects the respective chamber from the outflow opening. A control installation of the pneumatic device adjusts the operating state of the valve assembly. The line network is designed so that, in at least three of the operating states for venting the respective chamber, the connection between the respective chamber and the outflow opening is established by mutually dissimilar flow resistances.

Abstract: A mobile work machine is provided with a prime mover supported by a chassis, a first hydraulic pump driven by the prime mover, a work attachment powered by the prime mover, and a traction system. The traction system can include a ground engagement assembly for propelling the chassis. The mobile work machine can include an electronic controller configured to execute a traction speed control algorithm in which the position of the power reduction device is operated by the electronic controller to reduce available fluid pressure to a traction control device without receiving an actual traction speed feedback signal at the electronic controller. Alternatively, or in addition, a commanded position of the power reduction control device can be calculated by the electronic controller as a function of a requested prime mover operating speed demand reduced by a calculated adjustment factor.

Abstract: A control method of a work machine in which a rotation number of a fan that takes outside air into an engine room accommodating an engine varies with a rotation number of the engine, includes: executing first control of regenerating a collecting filter unit that collects particulates contained in exhaust gas of the engine by a temperature rise of the exhaust gas; when the work machine is changed from a steady state to a specific state, executing second control of decreasing an amount of working oil discharged from a hydraulic pump by driving of the engine; and, when the first control and the second control are concurrently executed, executing third control of increasing the rotation number of the engine.

Abstract: The disclosure relates to a hydraulic system including a reversing pump which has two delivery connections via which a hydraulic medium can be delivered from a tank in opposite delivery directions in order to hydraulically actuate an actuating element and supply a cooling and/or lubricating system. The hydraulic system also includes a valve assembly via which an actuating piston in a double-acting actuating cylinder can be supplied with hydraulic medium. A first delivery connection of the reversing pump is fluidly connected to a first pressure connection of the double-acting actuating cylinder. A second delivery connection of the reversing pump is fluidly connected to a second pressure connection of the double-acting actuating cylinder. The actuating piston is mechanically coupled to a valve piston of a valve, and the valve piston is mechanically coupled to a locking device and to the actuating element.

Abstract: A hydraulic system is provided with a pump supplying pressurized hydraulic fluid through a first supply line to a closed center control valve. From the control valve the fluid is directed through work lines to a hydraulic motor. Exhausted hydraulic fluid from the hydraulic motor is directed through the control valve to an exhaust line having a back pressure check valve set at a first pressure level. To keep the exhaust line fully charged a second supply line extends between the first supply line and the exhaust line. The second supply line is provided with a pressure reducing valve that is set at a second pressure level that is greater than the first pressure level of the back pressure check valve. An oil conditioning circuit is disposed between the back pressure check valve and a return tank for persistent hydraulic fluid conditioning.

Abstract: A hydraulic system, working vehicle, and method for producing hydraulic power to a hydraulic system of a working vehicle is provided. The hydraulic system includes a fixed displacement hydraulic pump and a speed and torque controlled electric motor for driving the hydraulic pump. An electric controller is arranged to adjust the speed of the electric motor and to thereby adjust produced hydraulic fluid flow and pressure in the system. Further, there is a bypass flow channel including a throttle element for directing limited continuous discharge fluid flow from the system.

Abstract: This hydraulic drive system includes: a hydraulic pump capable of changing a discharge flow rate of a working fluid; a meter-in control valve that controls a meter-in flow rate of the working fluid flowing from the hydraulic pump to a hydraulic actuator; a meter-out control valve that is provided separately from the meter-in control valve and controls a meter-out flow rate of the working fluid being drained from the hydraulic actuator into a tank; an operation device that outputs an operation command; a first pressure sensor that detects a drainage pressure of the hydraulic actuator; and a control device that sets a target meter-out flow rate according to the operation command from the operation device and controls an opening degree of the meter-out control valve on the basis of the drainage pressure detected by the first pressure sensor and the target meter-out flow rate.

Abstract: In some implementations, a hydraulic coupling connection includes a coupling disposed at an end of a hose and defining a flange having: a lower surface configured to engage a body of a valve; an upper surface; and an outer diameter surface connecting the lower surface and the upper surface, the outer diameter surface defining a first plurality of straight sides; and a split flange engaged with the coupling, the split flange having: a first lower surface configured to engage the body of the valve; a second lower surface configured to engage the upper surface of the flange; and an inner diameter surface connecting the first lower surface and the second lower surface, the inner diameter surface defining a second plurality of straight sides, wherein engagement between the first plurality of straight sides and the second plurality of straight sides is configured to secure the connection at a first angle.

Abstract: The present invention relates to a mechanism for changing the pitch of a propeller of a turbine engine, the mechanism comprising an electrohydraulic actuator that comprises: —an electric machine comprising a rotatable actuator shaft; —a pumping assembly comprising two hydraulic axial piston pumps, each comprising: o a barrel housed in a cavity filled with hydraulic fluid; o a set of cylinders formed in the barrel, each cylinder housing a translatable piston and comprising an inlet port and a delivery port; o and an inclined plate, the plate of a first pump comprising a crescent-shaped inlet port for circulating the hydraulic fluid when the plate is rotated in a first direction, and the plate of a second pump comprising a crescent-shaped inlet port for circulating the hydraulic fluid when the plate is rotated in a second direction.

Abstract: Some embodiments of the present disclosure provide a power system and a fracturing device. The power system includes an oil tank, a reduction gearbox and a hydraulic system. The reduction gearbox is provided with a lubricating system, and the lubricating system is communicated with the oil tank. The hydraulic system includes a hydraulic actuating member, and the hydraulic actuating member is communicated with the oil tank.

Abstract: The invention relates to an actuation device for at least one fluidically drivable load (10), such as a hydraulic actuator, consisting of at least one valve controller (V1) for controlling an alternating movement of each load (10) and at least one suspension device (14) which is connected between the valve controller (V1) and each load (10), wherein the suspension device (14) has an additional valve controller (V2), the valve piston (20) of which can be moved in a corresponding valve housing in a continuously adjustable manner. The invention is characterized in that a storage device (16) of the suspension device (14) is connected to the respective load (10) via a fluid path by means of the additional valve controller (V2) in a suspension position (V2.IV) of the valve piston (20) of the additional valve controller (V2).

Abstract: A hydraulic arrangement includes a hydraulic cylinder and a hydraulic pump for its pressure medium supply, which can be driven by an electric motor of the arrangement and can be fluidically connected to a cylinder chamber via a pressure medium flow path. At least one shutoff valve is provided in the pressure medium flow path, through which the pressure medium flow path can be hydraulically disconnected for load holding of the hydraulic cylinder without drive. An operating variable of the electric motor is determined or detected upon hydraulic disconnection of the pressure medium flow path, and the detected or determined operating variable is set and tracked on the electric motor upon setting a condition at which the pressure medium flow path is opened.

Abstract: Disclosed are an implement descending stability control method and system and a tractor. An outlet of a main pump is communicated with an inlet of a main overflow valve, an inlet of a constant-difference overflow valve and an inlet of an implement control valve. An oil outlet of the implement control valve is connected with a spring cavity of the constant-difference overflow valve through a steady-state throttle valve and is communicated with an inlet of a switching valve. An oil outlet of the switching valve is connected with a rodless cavity of a suspension cylinder in a suspension mechanism, and the rodless cavity of the suspension cylinder is communicated with an inlet of a descending valve. A rod cavity of the suspension cylinder is connected with an inlet of a secondary overflow valve.

Abstract: A hydraulic system for controlling one or more movable members on construction equipment such as a demolition robot, where the hydraulic system is configurable in a safe mode of operation in which at least one of the movable members is intended to be stationary. The system comprises a load sensing (LS) circuit and a first hydraulic pressure sensor arranged to sense a first LS pressure in a first LS circuit part of the LS circuit. The system also comprises a control unit arranged to monitor the sensed first LS pressure, compare the first LS pressure to a predetermined acceptance criterion associated with stationarity of the one or more movable members, and trigger a safety-related action by the hydraulic system in case the first LS pressure does not satisfy the acceptance criterion even though the safe mode of operation is configured.

Abstract: A hydraulic arrangement (1) including a supply port (P), a return port (T), a working port arrangement (L, R), and a valve (2) controlling a supply of hydraulic fluid from the supply port (P) to the working port arrangement (L, R), wherein the valve (2) includes a housing (4) and a spool (3) movable in lengthwise direction in the housing (4) and forming together with the housing (4) at least one flow path the resistance of which depends on the position of the spool (3) in the housing (4), and the spool (3) is actuated by a hydraulic pilot pressure (21, 22) in a pressure chamber (7, 8). In such a hydraulic arrangement a safety functionality should be achieved in a simple way. To this end the housing (4) includes a pilot pressure relief port (20) connected to the return port (T) via a shut-off valve (10) and the spool (3) after a predetermined stroke (13, 14) opens a connection between the pressure chamber (7, 8) and the pilot pressure relief port (20).

Abstract: An apparatus includes a hydraulic circuit that is configured to selectively open fluid communication between one portion of the hydraulic circuit and another portion of the hydraulic circuit, such as a reservoir, based on the flow of the hydraulic fluid in the one portion. When the flow of hydraulic fluid exceeds a selected threshold in the one portion of the hydraulic circuit, the flow of fluid urges the opening of a hydraulic component of the hydraulic circuit to allow fluid communication between the one portion and the reservoir to discharge fluid from the one portion.

Abstract: A throttle arrangement for sealing a sliding surface of a body in a piston compressor the throttle arrangement having annular sealing discs and a sealing disc holder having an L-shaped radial section having a first leg running in the axial direction and a second leg running transversely, the second leg being annular and having a bearing surface pointing in the direction of the high-pressure side, the sealing discs are stacked one on top of one another axially, the first leg being cylindrical extending from the bearing surface toward the high-pressure side, the axial height of the first leg H4 allow bearing surface to have axial play, the first leg gas passage openings, the first leg having a boundary surface facing in the sealing discs, aligned coaxially with the first limb and the body, a first annular gap RS1 is formed between the boundary surface and the sealing discs.