A hydraulic machine is provided. A boom actuator includes a large chamber and a small chamber. A recovery unit receives fluid discharged from the large chamber and then recovers energy. A recovery line connects the large chamber and the recovery unit. An accumulator is connected to the recovery line. A jack-up assist line connects the accumulator and the small chamber. A jack-up assist valve is disposed on the jack-up assist line to block flow of fluid from the accumulator to the small chamber in a first position and allow the flow of fluid from the accumulator to the small chamber in a second position. A controller controls movement of the jack-up assist valve. The controller may determine whether or not the hydraulic machine is in a jack-up condition, and when the hydraulic machine is determined to be in the jack-up condition, moves the jack-up assist valve to the second position.

A method of controlling a hydraulic actuator, wherein the hydraulic actuator includes a linear double-acting output member, and at least three working chambers in fluid connection with the output member, the working chambers having respective effective areas with a non-binary relationship; wherein the method includes selectively fluidly connecting each working chamber to either a high-pressure side or a low-pressure side to provide a plurality of discrete pressurization states of the hydraulic actuator; determining at least one of the pressurization states as a prevented pressurization state; and transitioning between a plurality of allowed pressurization states among the pressurization states while preventing transition to the at least one prevented pressurization state. A hydraulic actuator and a hydraulic system are also provided.

A hydraulic system includes a first electric machine connected to a first hydraulic machine and a second electric machine connected to a second hydraulic machine. An output side of the second hydraulic machine is connected to an input side of the first hydraulic machine. A hydraulic consumer is hydraulically coupled to an output side of the first hydraulic machine via a supply line and is powered by the first hydraulic machine. A return line hydraulically couples the hydraulic consumer to an input side of the first hydraulic machine. The second hydraulic machine provides a flow of hydraulic fluid to the input side of the first hydraulic machine if a requested flow from the first hydraulic machine exceeds a flow of the return line and recuperates energy if the requested flow from the first hydraulic machine is lower than the flow of the return line.

The disclosure relates to a hydraulic control block for controlling a pressure medium supply of a hydraulic cylinder of a hydraulic spindle. The hydraulic control block includes a generic hydraulic switching structure electively configurable in each of a plurality of specific hydraulic switching structures, each of the plurality of specific hydraulic switching structures having a respective hydraulic cylinder with a number of piston areas which differs from a number of piston areas in the respective hydraulic cylinders of each of the other of the plurality of specific hydraulic switching structures.

A hydraulic valve control unit is for an open center hydraulic system including a pump, a shunt valve and one or more actuator valves coupled to the shunt valve. Each actuator valve controls a corresponding actuator's position. The hydraulic valve control unit has a processor and a memory, containing instructions executable by the processor, and is configured to obtain user input data indicative of a desired actuator's position, determining opening area values of the one or more actuator valves using a predetermined relation dependent on the user input data, determining an opening area value of the shunt valve using the predetermined relation dependent on the user input data, controlling the shunt valve based on the opening area value of the shunt valve, and controlling the one or more actuator valves based on the opening area values of the one or more actuator valves.

An actuator operable to move a valve stem between an opened position and a closed position includes a cylinder including an open side and a close side, the cylinder coupled to the valve stem, a first pump connected to the cylinder and operable to deliver a first high-pressure fluid to the open side of the cylinder to move the valve stem toward the opened position, and a second pump separate from the first pump, the second pump connected to the cylinder and operable to deliver a second high-pressure fluid to the close side of the cylinder to move the valve stem toward the closed position.

The hydraulic system according to the invention comprises a hydraulic circuit with a low-pressure region and a high-pressure region; a volume- and/or speed-variable hydraulic machine, which is driven by a first electric motor and has an inlet and an outlet and provides a volume flow of a hydraulic fluid in the high-pressure region of the hydraulic circuit. The hydraulic system according to the invention further comprises at least one movable shaft, which is arranged in the high-pressure region of the hydraulic circuit; at least one valve, which separates the high-pressure region from the low-pressure region; and at least one hydraulic fluid container, which is hydraulically connected to the low-pressure region of the hydraulic circuit. The hydraulic system according to the invention also has a discharge line, which discharges hydraulic fluid from the leakage of the hydraulic machine, and a cooling line for transporting the hydraulic fluid in order to cool the electric motor, the discharge line and the cooling line being fluidically connected to at least one of the hydraulic fluid containers.

An energy recuperation system for construction equipment includes an actuator driving upward and downward operations of a work unit; an accumulator connected to the actuator; and a controller determining a predicted downward mode associated with the downward operation of the work unit, regulating a dischargeable lowest limit pressure of the accumulator to a target pressure corresponding to the predicted downward mode, and charging the accumulator having the dischargeable lowest limit pressure regulated to the target pressure with pressurized oil discharged from the actuator during the downward operation of the work unit to recuperate energy, and an energy recuperation method.

The electrohydrostatic actuator system according to the invention comprises a volume-variable and/or rotational-speed-variable hydro machine, which is driven by an electric motor, for providing a volume flow of a hydraulic fluid, and a main shaft which is movable by the hydraulic fluid and which has at least one first chamber, wherein the first chamber, with at least one first main hydraulic line and a first main valve, is hydraulically connected to the hydro machine via a connection line. The actuator system according to the invention further comprises a secondary shaft which is movable by the hydraulic fluid and which has at least one first chamber, wherein the first chamber, with at least one first secondary hydraulic line and a first secondary valve, is hydraulically connected to the hydro machine via a connection line. Furthermore, according to the invention, a hydraulic accumulator is hydraulically connected to the first secondary hydraulic line in the area between the first chamber of the secondary shaft and the first secondary valve.

A system for operating a work vehicle includes a hydraulic control assembly and a controller. The hydraulic control assembly includes a pump, accumulator, boom hydraulic cylinder, pin hydraulic cylinder, pin control valve, and ride control valve assembly. The boom hydraulic cylinder moves a boom of the work vehicle. The pin hydraulic cylinder moves a pin on the boom. The ride control valve assembly includes a charge valve and discharge valve. The charge valve is in fluid communication with the pump and the accumulator. The discharge valve is in fluid communication with the accumulator and a reservoir. The controller operates the work vehicle in a ride control mode and pin actuation mode. The pin actuation mode includes opening the charge valve with the discharge valve closed, and directing hydraulic fluid through the pin control valve.