A power unit with manual override control for a hydraulic system having an initial state and at least one operational state is provided, comprising: a tank for storing hydraulic fluid that moves between a first chamber and a second chamber of a hydraulic cylinder; a pump that routes the hydraulic fluid in and out of the tank; a first relief valve; a first solenoid valve configured to shift between a plurality of positions based on the at least one operational state of the hydraulic system; a first check valve connected to the first solenoid valve; a manual override control unit comprising: a second check valve; and a second solenoid valve configured to shift between a plurality of positions based on activation of a manual override control, wherein the activation of the manual override control returns the hydraulic system from the at least one operational state to the initial state.

An electrohydraulic system includes an output shaft, a hydraulic piston, and a preload device. The output shaft rotationally drives the valve and extends along a first axis. The hydraulic piston extends along a second axis perpendicular to the first axis, is actuated by a pressure medium, and rotates the output shaft. The preload device stores energy via preloading of an elastic element, which extends along a third axis, by a hydraulic cylinder and to transmit the energy to the output shaft in the event of a fault. The hydraulic piston is guided into first and second cylinder housings, and at least one of the cylinder housings is connected to the hydraulic cylinder. A check valve is arranged between the cylinder housing and the hydraulic cylinder, and is configured to decouple the preload device from the hydraulic piston, the blocking direction going from the hydraulic cylinder to the cylinder housing.

The subject matter of this specification can be embodied in, among other things, an electrohydraulic positioning control system that includes a shuttle valve configured to direct fluid flow between a selectable one of a first fluid port and a second fluid port, and a fluid outlet configured to be fluidically connected to a fluid actuator, a first servo valve controllable to selectably permit and block flow between the first fluid port, a fluid source, and a fluid drain, a second servo valve controllable to selectably permit and block flow between the second fluid port, the fluid source, and the fluid drain, a first servo controller configured to provide a first health signal and control the first servo valve based on a second health signal, and a second servo controller configured to provide the second health signal and control the second servo valve based on the first health signal.

Systems, devices, and methods are included for automotive hydraulic system smart safety switches that cut power to hydraulic motors when faults are detected using sensors, timers, and probes.

A power unit with manual override control for a hydraulic system having an initial state and at least one operational state is provided, comprising: a tank for storing hydraulic fluid that moves between a first chamber and a second chamber of a hydraulic cylinder; a pump that routes the hydraulic fluid in and out of the tank; a first relief valve; a first solenoid valve configured to shift between a plurality of positions based on the at least one operational state of the hydraulic system; a first check valve connected to the first solenoid valve; a manual override control unit comprising: a second check valve; and a second solenoid valve configured to shift between a plurality of positions based on activation of a manual override control, wherein the activation of the manual override control returns the hydraulic system from the at least one operational state to the initial state.

A magnetic force compensator for at least partially compensating a closing force required to shift a valve of a pneumatic positioner into a closed position using a magnetic device, the magnetic device including a permanent magnet; and a magnetic counterpart; wherein the magnetic device and the magnetic counterpart are configured to interact to create an attracting force for the at least partially compensation of the closing force; and wherein the magnetic force compensator is configured to be mechanically coupled to the valve of the pneumatic positioner.

A spool valve device includes: a housing with channels; a spool moving to change channel connection statuses; an electric actuator including an electric motor and linear-motion conversion mechanism, the motor rotating an output shaft by torque corresponding to a drive current supplied to the motor, the mechanism converting rotational output shaft movement into straight movement and applying thrust corresponding to the torque to the spool to change position; a biasing member applying biasing force to the spool against the actuator thrust; an angle detector detecting an motor output shaft angular position; a driving portion driving the motor by controlling drive current flow supplied to the motor based on a position command input and the angular position detected by the angle detector; and an abnormality determining portion calculating the spool position based on the detected angular position and determine presence or absence of operation spool abnormality.

The subject matter of this specification can be embodied in, among other things, a fluid valve assembly that includes a first fluid port, a second fluid port, a third fluid port, a valve spool configured to be positioned at a first position, a second position away from the first position, a third position away from the first position opposite the second valve position, the valve spool defining a first fluid duct configured to fluidly connect the first fluid port to the second fluid port in the first valve position, a second fluid duct configured to fluidly connect the first fluid port to the third fluid port in the second valve position, and a third fluid duct configured to fluidly connect the first fluid port to the second fluid port in the third valve position.

A hydraulic circuit includes a pump connected to a tank for supplying hydraulic liquid under pressure to a component via a directional control slide valve provided with a feed port connected to an inlet of the component and with a return port connected to an outlet of the component. The hydraulic circuit further includes a pressure limiter connected to the inlet of the component and the tank, and a feed control system for the hydraulic component including a pressure sensor installed upstream of the hydraulic component downstream of the feed port for supplying information about the pressure of the hydraulic liquid and a setpoint pressure. The feed control system further including an actuator for controlling the movement of the directional control slide valve, and a control unit for generating a control signal for the actuator based on information about the pressure measured at the feed port.

Working equipment including a hydraulically movable arm arrangement for a crane, an electric motor, a hydraulic pump, and a pump controller. An equipment controller is arranged to determine a maximum flow limit from the pump in dependence of a comparison of a current limit received from a battery system and a current consumption monitored by the pump controller, and to compare the determined limit with required flow of hydraulic fluid from the pump needed to move the movable arm arrangement in accordance with operating signals, and if the result does not fulfil a rule of a set of fluid control rules, the controller adapts the operating signals to reduce flow of hydraulic fluid to at least one of a plurality of actuators according to a rule of a set of adaptation rules, such that at least one rule of the set of fluid control rules is fulfilled.