A hydraulic valve assembly including a main control valve having a valve body housing a valve member that is movable between a first valve position and a second valve position. The hydraulic valve assembly further includes a mechanical interface operatively coupled to the movable valve member to manually move the movable valve member between the first valve position and the second valve position and one or more electro-hydraulic actuators operatively coupled to the movable valve member to automatically move the movable valve member between the first valve position and the second valve position in response to receiving a control signal from a controller.

A ram air turbine (RAT) restow system includes an actuator assembly with a piston interposed between an upper fluid compartment and a lower fluid compartment. The actuator assembly is configured to selectively move the piston between a deployed position and a stowed position. A hydraulic restow circuit is interposed between the actuator assembly and a hydraulic fluid system that is configured to output fluid. The hydraulic restow circuit includes a restow valve configured to operate in a first position that establishes a first fluid path to deliver the fluid to the upper fluid compartment and a second position that establishes a second fluid path to deliver the fluid to the lower fluid compartment.

A work vehicle includes: a hydraulic pump driven by an engine; a hydraulic actuator that is driven by hydraulic oil supplied from the hydraulic pump; a switching valve configured to switch from one to the other of a first state in which the hydraulic oil supplied from the hydraulic pump is supplied to a first channel and a second state in which the hydraulic oil supplied from the hydraulic pump is supplied to a second channel; a restriction operation device configured to generate an operation signal that restricts the drive of the hydraulic actuator; and a controller that controls the switching valve. The controller includes: an operation signal acquisition unit configured to acquire the operation signal; and an instruction output unit configured to output, to the switching valve, a control instruction that restricts the drive of the hydraulic actuator with the engine driving, in response to the operation signal.

Manual hydraulic override pumps for use with actuators are described herein. An example apparatus includes a manifold including a reservoir port to be fluidly coupled to a reservoir of fluid, a pump port to be fluidly coupled to a pump, a first actuator port to be fluidly coupled to a first chamber of an actuator, and a second actuator port to be fluidly coupled to a second chamber of the actuator. The example apparatus also includes a rotor disposed in a cavity formed in the manifold. The rotor is rotatable between a first actuating position in which the rotor fluidly couples the first actuator port and the pump port, and a second actuating position in which the rotor fluidly couples the second actuator port and the pump port.

A control device for a hydraulic machine such as a revolving excavator work machine having a structure that can cope with such an engine output decreasing environment as a work under a low atmospheric pressure at a high altitude without generating noise caused by engine rotation number increase. The control device corrects a control output value to be applied to an electromagnetic proportional valve for load-sensing valve control in a load-sensing type pump control system, based on a detected state quantity related to the engine output decreasing environment. When an engine speed-sensitive pump control system is adopted, a control output value generated based on a detected decrease in the actual engine rotation number is combined with a control output value generated by the load-sensing type pump control system.

An adjustable ride control circuit and method that includes a head valve that controls flow between a boom cylinder head intake and an accumulator, and a rod float valve that controls flow between a boom cylinder rod intake and tank, where the rod float valve is electronically adjustable and proportionally controls flow restriction. A controller controls ride control activation, and adjustment of the head and rod float valves. When ride control is activated, the head valve allows flow between the head intake and the accumulator, and the controller automatically adjusts the rod float valve. When ride control is deactivated, the head valve blocks flow between the head intake and the accumulator, and the rod float valve blocks flow between the rod intake and tank. An enable valve can control positioning of the head valve. A flow selector can select manual or automatic adjustment of the rod float valve.

An engine-driven oil pump has an engine, a pump unit, an oil diverting device, a manual control unit, and a remote control unit. The engine is connected to the pump unit. The oil diverting device is mounted on the pump unit and selectively pumps hydraulic oil from the pump unit into the manual control unit or the remote control unit. With the engine, the engine-driven oil pump can generate power independently instead of relying on external power supply. Besides, the electromagnetic valve of the remote control unit allows the user to remotely control the oil path of the hydraulic oil, so the user is not required to stay along the engine-driven oil pump to manually switch the oil path, and therefore the engine-driven oil pump is more efficient regarding manpower.

Manual hydraulic override pumps for use with actuators are described herein. An example apparatus includes a manifold including a reservoir port to be fluidly coupled to a reservoir of fluid, a pump port to be fluidly coupled to a pump, a first actuator port to be fluidly coupled to a first chamber of an actuator, and a second actuator port to be fluidly coupled to a second chamber of the actuator. The example apparatus also includes a rotor disposed in a cavity formed in the manifold. The rotor is rotatable between a first actuating position in which the rotor fluidly couples the first actuator port and the pump port, and a second actuating position in which the rotor fluidly couples the second actuator port and the pump port.

A ram air turbine (RAT) restow system includes an actuator assembly with a piston interposed between an upper fluid compartment and a lower fluid compartment. The actuator assembly is configured to selectively move the piston between a deployed position and a stowed position. A hydraulic restow circuit is interposed between the actuator assembly and a hydraulic fluid system that is configured to output fluid. The hydraulic restow circuit includes a restow valve configured to operate in a first position that establishes a first fluid path to deliver the fluid to the upper fluid compartment and a second position that establishes a second fluid path to deliver the fluid to the lower fluid compartment.

A large manipulator includes a chassis, a turntable arranged on the chassis and rotatable around a vertical axis via a rotary drive, and an articulated mast including two or more mast segments pivotably-movably connected, via articulated joints, with the respectively adjacent turntable or mast segment via a respective drive. The large manipulator further includes a mast sensor system configured to detect position of at least one point of the articulated mast or a pivot angle of at least one articulated joint and configured to generate sensor output signals. The large manipulator further includes a control device configured to actuate the drive in a normal operation for mast movement and to limit speed of movement of the articulated mast depending upon the sensor output signals. The drive is manually controllable in an emergency operation. The large manipulator further includes at least one limiting means, which, in the emergency operation, limit speed of the drive to a pre-specified maximum value.