An electrohydrostatic actuator system comprising: a volume- and/or speed-variable hydraulic machine which is driven by an electric motor, for providing a volumetric flow of a hydraulic fluid; a differential cylinder with a piston side and a ring side; and at least one pretensioning source. The actuator system has a closed hydraulic circuit, wherein, during operation, the hydraulic fluid in the hydraulic circuit is pressurized by means of the hydraulic machine and/or the pretensioning source. Furthermore, according to the invention, the differential cylinder provides a power motion operating mode and a rapid motion operating mode. In order to balance a volume of the hydraulic fluid in the closed hydraulic circuit, according to the invention an expansion reservoir is connected to the piston side of the differential cylinder via a valve.

A fluid supply system supplying multiple fluid consumers of a vehicle with fluid, the fluid supply system including: a first pump supplying a first fluid consumer, arranged in a first supply circulation of the vehicle, with fluid; a second pump supplying a second fluid consumer, arranged in a second supply circulation of the vehicle, with fluid; and a directional control valve adjustable between a first valve position and at least one other, second valve position and preferably includes an electromagnetic device for adjusting. The directional control valve allows the fluid to be delivered from the second pump into the first supply circulation in the first valve position and separates the first supply circulation from the second pump, or allows the fluid to be delivered from the second pump into the first supply circulation only to a restricted extent as compared to the first valve position, in the second valve position.

A working machine includes a machine body, a first hydraulic actuator mounted on the machine body, a first control valve that controls the first hydraulic actuator, a controller that controls the first control valve, and a second hydraulic actuator that is different from the first hydraulic actuator. When the second hydraulic actuator and the first hydraulic actuator are operated in combination, the controller reduces the amount of change in the flow rate of a hydraulic fluid supplied from the first control valve to the first hydraulic actuator with respect to changes in a manipulation amount to operate the first hydraulic actuator to a value smaller than that when the first hydraulic actuator is solely operated.

The present invention provides an improved high-low hydraulic system for compacting machinery, such as balers, horizontal balers, compactors, transfer station compactors, and the like. The high-low hydraulic system comprises at least one double rotary pump, a plurality of directional control valves, a pilot-operated back pressure reducing valve, a flow control valve, a plurality of one-way valves, and a plurality of pressure switches. The high-low hydraulic system may be regenerative or non-regenerative and provides many advantages over conventional hydraulic systems. Such advantages include greater system efficiency due to a reduced back pressure during the time of the retraction stroke and clever flow sequencing, mitigation of hydraulic shocks at the beginning and end of compaction and retraction strokes, and reduced cycle time of the cylinder during operation due to the concurrent filling of the rod end side during decompression of the blind end side after the compaction stroke. Moreover, the present high-low hydraulic system allows for the cylinder to operate at three or more independent speeds. Additionally, the present high-low hydraulic system may also comprise an accumulator and pressure transducer that further assist with substantially maintaining a predetermined hydraulic pressure on the blind end side after the completion of the compaction stroke.

The present disclosure relates to a hydraulic drive system having a hydraulic circuit architecture operable in first and second modes. In a first mode, a main hydraulic pump (22) is used to drive a hydraulic actuator (24) via a closed hydraulic circuit, and a charge pump (42) provides charge flow to the closed hydraulic circuit. In a second mode the main pump set to zero displacement and the charge pump (42) is used to drive the hydraulic actuator (24).

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.

A hydraulic system for a work vehicle has a first hydraulic circuit at a first nominal pressure and a second hydraulic circuit at a second nominal pressure different than the first nominal pressure. A dual-chamber hydraulic reservoir includes a first tank associated with the first hydraulic circuit and defining a first opening and a second tank associated with the second hydraulic circuit and defining a second opening. An exchange system has a particulate filter disposed within an exchange path between the first opening of the first tank and the second opening of the second tank. The exchange system is configured to resupply the first tank with hydraulic fluid from the second tank.

The present disclosure relates to a hydraulic circuit, comprising: a hydraulic displacement unit for driving an implement; a hydraulic machine fluidly connected or selectively fluidly connected with the hydraulic displacement unit the hydraulic machine having a fixed hydraulic displacement; an electric machine drivingly engaged or selectively drivingly engaged with the hydraulic machine; a hydraulic pump fluidly connected or selectively fluidly connected with the hydraulic displacement unit, the hydraulic pump having a variable hydraulic displacement; and an electric motor drivingly engaged or selectively drivingly engaged with the hydraulic pump.

A hydraulic circuit includes a prime mover that is configured to generate an oscillating flow of hydraulic fluid, and an actuator that is driven by the prime mover and configured to provide oscillating motion and to be connected to a load in each direction of the motion. The hydraulic circuit also includes a reclamation device that is disposed in the hydraulic circuit between the prime mover and the actuator. The reclamation device captures and stores a portion of hydraulic fluid displaced from the actuator during a transition between opposed motions, where the portion of hydraulic fluid corresponds to an amount of hydraulic fluid equal to a volume of fluid required to compensate for compression of fluid within the hydraulic circuit due to system pressure and load pressure. The stored fluid is used by the circuit in a subsequent motion.

A portable hydraulic power unit includes a frame, a fluid tank supported by the frame, and a manifold supported by the frame. The fluid tank is configured to store a supply of hydraulic fluid for powering a hydraulically-driven tool. A reciprocating pump is mounted on the exterior of the fluid tank and on the exterior of the manifold. The reciprocating pump is secured to the fluid tank and the manifold with fasteners extending through a cylinder body of the reciprocating pump.