A hydraulic power generating system includes a hydraulic motor, a bidirectional generator connected to the hydraulic motor, a hydraulic cylinder, first and second tubes, a piston structure having a piston and first and second links, and a power driving device connected to the first link. The piston divides the hydraulic cylinder into first and second chambers. The first and second links are connected to the piston and disposed through the first and second chambers, respectively. The first tube is communicated with the first chamber and the hydraulic motor. The second tube is communicated with the second chamber and the hydraulic motor. When the power driving device drives the piston toward the first chamber, hydraulic oil is pumped to the hydraulic motor for rotating the bidirectional generator. When the power driving device drives the piston toward the second chamber, the hydraulic oil is pumped to rotate the bidirectional generator reversely.

A self-rotation graphene heat-dissipation device for a direct-drive electro-hydrostatic actuator, that includes inner and outer walls of a shell eccentrically arranged relative to each other, the shell sleeves on an outer side of a self-rotation mechanism. The self-rotation mechanism is arranged on an outer side of a shaft; the shaft is coaxial with the inner wall of the shell and connected with outer and inner end covers. The self-rotation mechanism includes a rotor and blades, the rotor sleeves on the shaft and is connected with the outer and inner end covers. The rotor is slidably connected with the blades, and outer walls of the blades are closely attached to the inner wall of the shell. Graphene heat-dissipation layers are coated on outer walls of all of the shell, blades, the rotor, the inner and outer end covers respectively.

A hydraulic assembly for a vehicle transmission includes a hydraulic pump for providing a system pressure within a hydraulic circuit, a pressure accumulator for temporarily supplying pressure to the hydraulic circuit, and a valve assembly for charging the pressure accumulator after a predetermined pressure threshold value of the system pressure has been reached or exceeded. The valve assembly is hydraulically connected between the pump and the pressure accumulator.

A closed-circuit, self-contained hydraulic axis includes an electric motor, a hydraulic cylinder configured to be connected to a load and a main pump driven by the electric motor to pump hydraulic fluid through the circuit. Pressure connections of the pump are connected to the respective chambers of the cylinder such that the cylinder rod is configured to extend and retract depending on a direction of flow of the hydraulic fluid through the main pump. The hydraulic axis includes a main accumulator connected to the pump via first control valve, an energy storage accumulator connected to the pump via a second control valve, and a charge pump. The hydraulic axis is switchable between a first operating mode that is free of energy storage in the energy storage accumulator, and a second operating mode in which energy is stored in the energy storage accumulator.

The invention relates to an actuator device comprising at least one output element, which can be applied with a fluid and can thereby be moved into at least one retaining position. An actuator is provided which can be operated in a pumping operation by controlling the actuator, in which at least one part of the actuator can be alternatingly moved in a first direction and in a second direction opposite the first direction via the controlling of the actuator, whereby the fluid can be conveyed to the output element in order to apply the output element with the fluid. A discharge channel is also provided, via which the fluid can be discharged from the output element.

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 hydraulic machine. 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 a first point on the recovery line. A discharge valve is disposed on the recovery line between the first point and the recovery unit. A first sensor measures a pressure in the accumulator. A controller controls opening and closing of the discharge valve. The controller performs anti-bouncing control of: determining a target pressure in the accumulator corresponding to a load pressure applied to fluid in the large chamber by a load according to a predetermined correspondence; and controlling the opening and closing of the discharge valve such that the pressure in the accumulator measured by the first sensor reaches the target pressure.

An electro-hydrostatic actuator system for a press drive, having an upper piston with a press surface, which acts from a first direction, wherein the press surface of the upper piston is actuated by means of a piston rod in a hydraulic cylinder of the upper piston and traverses a first distance in a press run, and a first electro-hydrostatic actuator for driving the upper piston, comprising a first pump and a first motor generators which is controlled by a first controller. The system furthermore comprises at least one auxiliary piston with a press surface, which acts from a second direction opposite the first direction, wherein the press surface of the auxiliary piston is actuated by means of a piston rod in a hydraulic cylinder of the auxiliary piston and traverses a second distance in the press run, and a second electro-hydrostatic actuator for driving the at least one auxiliary piston, comprising a second pump and a second motor generator which is controlled by a second controller. The second motor generator is operated as a generator in the press run, thereby generating energy which is provided to the first motor generator or auxiliary piston, which are operated as motors, via the common DC bus.

The present disclosure relates to a motion control unit that is capable of receiving electrical power from an electrical power source and hydraulic power from a hydraulic power source. The motion control is configured to produce a blended power output derived from the electrical and hydraulic power which can be used to power a hydraulic actuator. The motion control unit can also split hydraulic power recovered from hydraulic actuator to the electrical power source and the hydraulic power source.

A lift system includes a lift structure and a lift structure actuation assembly. The lift structure can actuate between a lowered position and a raised position. The lift structure actuation assembly includes a hydraulic cylinder operably coupled with the lift structure, a motor, a hydraulic pump powered by the motor, and a flow control assembly that can limit hydraulic fluid exiting the hydraulic cylinder to a maximum volumetric flow rate. The hydraulic pump can pump hydraulic fluid into the hydraulic cylinder in order to raise the lift structure. The lift structure actuation assembly can lower the lift structure in a fast descent mode and a slow decent mode. In the slow descent mode, the hydraulic pump pumps hydraulic fluid toward the hydraulic cylinder such that the hydraulic fluid exits the hydraulic cylinder at a slower volumetric flow rate compared to the maximum volumetric flow rate.