Abstract: The present invention relates to an electric driven hydraulic power system for heavy equipment, and more particularly, to a hydraulic power system, which includes a hydraulic pump operated by a battery and a motor, a supply line for supplying a hydraulic oil that is supplied by the hydraulic pump, a plurality of actuators, and a controller for controlling the motor and the actuators, in which electrical efficiency is significantly improved.

Abstract: A hydraulic excavator drive system includes: a first pump connected to a head-side chamber of a boom cylinder; and a second pump that supplies hydraulic oil to one of, or both, an arm cylinder and a bucket cylinder. The first pump is driven by an electric motor. The drive system further includes a switching valve that is in a first position at a boom raising operation and in a second position at a vehicle body lifting operation. The first position is a position in which the switching valve brings a rod-side chamber of the boom cylinder into communication with a tank, and the second position is a position in which the switching valve brings the rod-side chamber into communication with the second pump.

Abstract: A hydraulic excavator drive system includes: a first pump that is connected to a head-side chamber of a boom cylinder by a head-side line and to a rod-side chamber of the boom cylinder by a rod-side line to form a closed circuit; and a second pump that supplies hydraulic oil to at least one of an arm cylinder or a bucket cylinder. The hydraulic excavator drive system further includes a switching valve located on a relay line that connects a supply line extending from the second pump to the rod-side line. The switching valve opens the relay line at a boom raising operation and blocks the relay line except at the boom raising operation.

Abstract: A marine hydraulic system and method of use for reducing cyclic loading of the pump(s) and motor(s) and an amount of accumulator storage required in a hydraulic system. A closed loop logic controller comprising at least one control algorithm for each pump/motor pair utilized in a single hydraulic system is utilized to reduce load fluctuations on the motors, allow the use of common pressure compensated, variable displacement (VDH) pumps, reduce the number and/or volume of system accumulators and equalize wear throughout the system.

Abstract: A hydraulic pump/motor includes: a cylinder block rotating about a rotation axis; a piston in a cylinder bore; and a valve plate facing a cylinder port. The valve plate includes: a high pressure port through which oil discharged from the cylinder port flows; a low pressure port through which the oil to be sucked into the cylinder port flows; a region disposed between the high and low pressure ports in a circumferential direction of the rotation axis and including a top dead center position facing the cylinder port of the cylinder bore in which the piston moved to a top dead center is disposed; and a residual pressure release port between the top dead center position and the low pressure port in the region. The residual pressure release port includes first and second ports disposed at positions different from each other in the radial direction of the rotation axis.

Abstract: A cylinder has a piston part, a cylinder part, and a pipe section connected to the piston or cylinder parts. A portion of the pipe section encloses a pressure compartment which receives a fluid to apply a pressure on a pressure surface so the piston part is displaced in a first stroke direction. A first return pressure compartment receives a fluid to apply a pressure on a first return pressure surface so that the piston part is displaced in a second return stroke direction. The first return pressure compartment is positioned on the outside of the pipe section, and the area of the first return pressure surface is substantially equal to the area of the return pressure surface so that a volume-neutral operation of the cylinder is provided. Also described is a hydraulic system, an excavator comprising the cylinder and a procedure for operation of the cylinder.

Abstract: A system includes a variable displacement pump (VDP) with a pump inlet and a pump outlet. The VDP is configured to receive a flow at the pump inlet at a first pressure and to outlet a flow from the pump outlet at a second pressure elevated relative to the first pressure. The VDP includes a variable displacement mechanism configured to vary the second pressure. A controller is operatively connected to a pressure sensor and to the variable displacement mechanism for control of the VDP. An output splitter is configured to split flow from the pump outlet to a first outlet branch and to a second outlet branch for supplying two different systems each having a different pressure schedule. The output splitter is operatively connected to the controller, which is configured to control the output splitter to regulate pressure in both of the first and second outlet branches.

Abstract: A cylinder includes a cylinder tube, a first closure part, a second closure part, and a piston unit. The cylinder tube has a first tube end and a second tube end. The tube and end closure parts define a cylinder interior. The piston unit defines at least one working space in the cylinder interior. The first closure part is connected to the tube by a first peripheral laser ring weld and the second closure part is connected to the tube by a second peripheral laser ring weld. The laser ring welds each define a fluid-tight sealing plane. A peripheral sealing ring is located between each closure part and a tube inner wall at an axial distance from the associated laser ring weld seam. The peripheral sealing ring defines a pressure-separated ring section between the peripheral sealing ring and the associated laser ring weld seam.

Abstract: An electric work vehicle includes a hydraulic actuator and a pump configured to supply hydraulic fluid to the hydraulic actuator, with the pump being operable within an operating speed range extending between a minimum operating speed value and a maximum operating speed value. Furthermore, the electric work vehicle includes a sensor configured to capture data indicative of a temperature of the hydraulic fluid and a controller communicatively coupled to the sensor. As such, the controller is configured to monitor the temperature of the hydraulic fluid relative to a predetermined minimum fluid temperature as the pump is operating within the operating speed range. In addition, the controller is configured to adjust the operating speed range of the pump by increasing at least one of the minimum operating speed value or the maximum operating speed value when the monitored temperature of the hydraulic fluid falls below the predetermined minimum fluid temperature.

Abstract: The present invention relates to a kinetic pumping system that transforms the kinetic energy contained in fluid waves to generate a positive reciprocating displacement flow with control modulation with controlled flow modulation. This system is one more alternative in the green technologies market that contributes to solving the problem of climate change and provides an alternative to eliminate the carbon footprint by replacing traditional fluid pumping systems. Its objective is to provide a pumping system with a positive reciprocating kinetic displacement, capable of generating flow and pressure that can be used or the desalination of seawater and for the generation of electrical energy and that, due to its configuration, overcomes the limitations of conventional systems, including those categorized as land, as well as maritime or coastal.

Abstract: Provided is a construction machine in which travel operability is not impaired when a combined operation is performed in which a single-rod hydraulic cylinder is driven during a travel operation. A hydraulic excavator includes a controller that controls the delivery direction and delivery flow rate of a closed-circuit pump, opens and closes a travel switching valve and an assist switching valve, and controls the delivery flow rate of the open-circuit pump, according to a travel operation lever and a work operation lever. The controller holds the assist switching valve in a closed position irrespective of whether or not the work operation lever is operated in a case where the travel operation lever is operated.

Abstract: A pumped-storage hydropower generation tower employing conduit turbines installed in multiple stages, according to the present invention, comprises: a pump (400) disposed in a pumping-up pipe (410) so as to pump up water that fills a lower reservoir (300) to an upper reservoir (200); a water-guide pipe channel (500) having an inlet water-guide conduit (510) connected to the bottom surface on one side of the upper reservoir (200) so as to extend to the position of the lower reservoir (300) along a helical sloping channel (100) such that a flow rate for power generation passes therein; and a conduit turbine unit (600) comprising a driving shaft (2) extending through the center of a conduit (22) through which the flow rate passes, conduit support bodies (4) installed so as to rotate freely while supporting the driving shaft (2), the conduit support bodies (4) having arms (6) extending toward the inner surface of the conduit (22), a propeller (7) fixed to the driving shaft (2) between the conduit support bodies (

Abstract: A first MR sensor and a second MR sensor are a combination of a first magnetic resistance effect element pattern and a second magnetic resistance effect element pattern. The first MR sensor and the second MR sensor are disposed a prescribed distance apart such that, when the first MR sensor receives the greatest quantity of the magnetic field component of a magnet oriented parallel to the axial direction of a piston, the second MR sensor receives the greatest quantity of the magnetic field component of a magnet oriented parallel to the radial direction of the piston.

Abstract: One embodiment of a hydraulic system for a machine has a first hydraulic circuit including a first pump coupled to a first hydraulic actuator configured to move a first implement of the machine. A second hydraulic circuit includes a second pump coupled to a second hydraulic actuator configured to move a second implement. An electric motor mechanically couples to the first pump and to the second pump. An operator interface receives input from an operator requesting movement of the first and second implements. A controller communicatively coupled to the electric motor and to the operator interface determines, based on the requested movement of the first and second implements respectively, first and second flow allocations respectively for the first and second pumps and determines respective target displacements for the first and second pumps.

Abstract: A work machine includes: a hydraulic actuator that is driven by a hydraulic fluid from a hydraulic pump; an open-center directional control valve that is arranged on a center bypass line, and controls a flow of the hydraulic fluid to be supplied to the hydraulic actuator; a CB cut valve arranged between a directional control valve and a hydraulic working fluid tank on the center bypass line; and a machine controller that controls an opening of the CB cut valve. The machine controller restricts the opening of the CB cut valve when operation on the hydraulic actuator is in a fine operation state in which the operation on the hydraulic actuator is within a predetermined range representing a region of fine operation, and the fine operation state is continued longer than a predetermined period, and fully opens the CB cut valve otherwise.

Abstract: A system includes a piston assembly. The piston assembly includes a crown portion having a crown, an outer wall coupled to the crown, a first inner wall disposed inside of the outer wall, a first fluid chamber disposed radially between the outer wall and the first inner wall, and an angled wall insert. An opening extends into the first fluid chamber in an axially inward direction. The outer wall, the first inner wall, the first fluid chamber, the opening, and the angled wall insert extend circumferentially about a central axis of the piston assembly. The angled wall insert is disposed in the opening, and the first fluid chamber is disposed axially between the crown and the angled wall insert.

Abstract: An electric work vehicle a pump configured to supply hydraulic fluid to a component of the electric work vehicle. Moreover, the electric work vehicle includes a sensor configured to capture data indicative of a pressure of the hydraulic fluid and a controller communicatively coupled to the sensor. As such, the controller is configured to monitor the pressure of the hydraulic fluid relative to a predetermined threshold pressure value based on the data captured the sensor. In addition, the controller is configured to control the operation of the pump such that the pump is switched from a first operating speed range to a second operating speed range when the monitored pressure of the hydraulic fluid falls below the predetermined threshold pressure value.

Abstract: A wave energy converter (WEC) system includes a float, a drivetrain, a reaction structure coupled to the drivetrain by at least one tendon, and a power dissipation system coupled to the drivetrain. The power dissipation system is configured to manage peak loads in the WEC system by dissipating peak energy spikes caused by relative movement of the reaction structure and the float.

Abstract: The first piston of the first cylinder and the second piston of the second cylinder are connected so that the first piston and the second piston have the same displacement. The cross-section area of one side of the first piston is the smallest, and the cross-section area on the same side of the second piston is the third smallest. The two air chambers of the first cylinder and the two air chambers of the second cylinder are referred to as a first air chamber, a second air chamber, a third air chamber, and the fourth air in ascending order in the cross-section area. The control valve connects the air pressure source to the first air chamber, connects the second air chamber to the third air chamber, and opens the fourth air chamber to the atmosphere in the forward stroke.

Abstract: Embodiments of the disclosure include a redundant control system for a vehicle. The redundant control system includes first and second actuator pistons mechanically coupled to one another and disposed in respective first and second fluid chambers. The first and second actuator pistons are movable by first and second primary stages. One of the primary stages includes a bypass valve with a pilot valve actuatable in response to movement of the first actuator piston.