A hydraulic system for a working machine, the system comprising: an electric machine connected to a first hydraulic machine and to a second hydraulic machine via a common axle, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine, wherein the first hydraulic machine is a variable displacement hydraulic machine with unidirectional flow; at least one hydraulic consumer hydraulically coupled to an output side of the first hydraulic machine via a supply line and configured to be powered by the first hydraulic machine; a first return line hydraulically coupling the hydraulic consumer to the input side of the first hydraulic machine.

The present disclosure generally relates to a railroad track ballast tamping vehicle and associated methods of use, wherein the vehicle comprises: a rigid frame; a variable-displacement servo-pump operatively coupled to the vehicle; at least one linear hydraulic actuator operatively coupled to the frame at a proximal end of the at least one linear hydraulic actuator and comprising: at least one internal cavity for receiving hydraulic fluid from the variable-displacement servo-pump via a hydraulic hose; and an actuator rod passing through a first internal cavity and a second internal cavity of the at least one linear hydraulic actuator; and a tamping tool operatively coupled to a distal end of the at least one linear hydraulic actuator. A tamping pad associated with the tamping tool may be lowered into ballast underlying railroad tracks and between railroad track ties for performing ballast tamping operations.

A header is supported by a pair of hydraulic float cylinders, where a float pressure to the cylinders is directly controlled by an electronic control supplying a variable control signal to a PPRR valve arrangement to maintain the float pressure at a predetermined value. At the set pressure a predetermined lifting force is provided to the header. A position sensor is used to generate an indication of movement and/or acceleration and/or velocity. The electronic control is arranged, in response to changes in the sensor signal, to temporarily change the control signal to vary the lifting force and thus change the dynamic response of the hydraulic float cylinder. A lift force greater than that required to lift the header can be provided by a lift cylinder and can be opposed in a controlled manner to apply a controlled downforce by the back of the same cylinder or by a separate component.

A hydraulic system for a rear gate of a baler implement includes a fluid circuit having a first portion connected to and disposed in fluid communication with a first fluid port of a hydraulic cylinder. A flow bypass assembly is disposed in the first portion of the fluid circuit. The flow bypass assembly includes a flow rate control valve selectively moveable between a first position allowing fluid communication therethrough at a first flow rate, and a second position blocking fluid communication therethrough. The flow bypass assembly further includes a bypass passageway for circulating the fluid when the flow rate control valve is closed. A flow restriction is disposed within the bypass passageway to provide a second flow rate that is less than the first flow rate.

To be capable of dealing with a machine body lifting operation or a sudden operation, while improving energy efficiency, during a boom-lowering operation, and achieving the reduction of the number of parts, in a construction machine equipped with a boom. It is configured such that a first region Y1 at which a recovery valve passage 16e is opened and a supply valve passage 16f is closed and a second region Y2 at which the recovery valve passage 16e and the supply valve passage 16f are opened, are provided at an operating position of a first boom control valve 16 during the boom lowering operation, and the first boom control valve 16 is positioned at the first region Y1 when neither a machine body lifting operation nor the sudden operation is performed during the boom-lowering operation, and at the region Y2 when the machine body lifting operation or the sudden operation is performed.

A landing gear lifting/lowering EHA system includes: a hydraulic actuator configured to lift and lower the leg of an aircraft; at least one electrically operated hydraulic pump; a hydraulic path; a pressure sensor attached to the hydraulic actuator or the hydraulic path and configured to output a measurement signal corresponding to hydraulic pressure; and a controller configured to output a control signal to the electrically operated hydraulic pump, wherein, when a state in which the hydraulic pressure exceeds a set pressure continues for a set time, the control unit stops the electrically operated hydraulic pump in operation and resumes the operation of the electrically operated hydraulic pump after the hydraulic pressure drops to or below a second set pressure after the electrically operated hydraulic pump is stopped.

A work vehicle a computing system configured to receive first and second input associated with controlling the operation of the first and second hydraulic load, respectively. Furthermore, the computing system is configured to control the operation of a first or second flow control valve corresponding to the one of the first or second hydraulic loads associated with the greater hydraulic fluid pressure such that the corresponding adjustable orifice is at a maximum flow position. Additionally, the computing system is configured to determine the first and second pressures of the hydraulic fluid being supplied to the first or second hydraulic loads. Moreover, the computing system is configured to control the operation of the first or second flow control valve corresponding to another of the first or second hydraulic loads based on the corresponding received first or second input and the determined first and second pressures.

A hydraulic system for an agricultural system includes a hydraulic circuit and a bi-directional filter disposed on a bi-directional fluid line of the hydraulic circuit. The bi-directional filter includes a check valve fluid line having a check valve configured to block a fluid from flowing through the check valve fluid line in a first direction and to enable the fluid to flow through the check valve fluid line in a second direction, opposite the first direction, and a filter fluid line having a filter configured to enable the fluid to flow through the filter fluid line in the first direction and the second direction. The filter is configured to block particles that are greater than a threshold size from passing through the filter fluid line, and the filter fluid line is in a parallel flow configuration with respect to the check valve fluid line.

Provided is a work machine which can achieve both of excellent operability when an operator manually operates a machine body or a work device and an accuracy of control of the machine body or the work device when a controller performs automatic control. The controller is configured to, in a case where the automatic control function selector switch gives an instruction to disable the automatic control function, adjust an opening amount of a bleed-off valve to a maximum opening amount or an opening amount corresponding to input amounts of control levers, and in a case where the automatic control function selector switch gives the instruction to enable the automatic control function, adjust the opening amount of the bleed-off valve, in at least part of an operation region of the control levers, so as to be smaller than the opening amount with the instruction to disable the automatic control function being given.

A hydraulic circuit includes a hydraulic power unit, a first cylinder pair coupled with the hydraulic power unit, and a second cylinder pair coupled with the hydraulic power unit in parallel with the first cylinder pair. Re-phasing valves coupled with each cylinder of the first and second cylinder pairs are activated when a respective one of the cylinders reaches one of a fully extended or a fully retracted position. The hydraulic circuit incorporates the serially plumbed, re-phasing cylinders for synchronized movement in a system with multiple pairs of cylinders.