Provided is a hydraulic drive device configured not to be increased in length in an axial direction. The hydraulic drive device is provided with a body portion for converting energy of a supplied pressure oil into rotational power, the body portion including an output shaft configured to rotate along a rotational axis by the rotational power, a hydraulic block disposed in an extending direction of the output shaft of the body portion and having an oil passage for supplying the pressure oil to the body portion, and a rotation sensor for detecting rotation of the output shaft, at least part of the rotation sensor being disposed in the hydraulic block.

Provided is a hydraulic drive device configured not to be increased in length in an axial direction. The hydraulic drive device is provided with a body portion for converting energy of a supplied pressure oil into rotational power, the body portion including an output shaft configured to rotate along a rotational axis by the rotational power, a hydraulic block disposed in an extending direction of the output shaft of the body portion and having an oil passage for supplying the pressure oil to the body portion, and a rotation sensor for detecting rotation of the output shaft, at least part of the rotation sensor being disposed in the hydraulic block.

In a flow rate controller and a drive device, a housing is provided therein with a first flow passage, a second flow passage adjacent to the first flow passage, a first throttle valve provided to the first flow passage, and a second throttle valve provided to the second flow passage. A pilot check valve is provided to the second flow passage and is connected in series to the second throttle valve. A pilot air flow passage communicates with a pilot port of the pilot check valve for supplying and discharging pilot air, and a third throttle valve is provided to the pilot air flow passage. In response to the pressure of the pilot air, the pilot check valve switches between a state in which the passage of exhaust air discharged from an air cylinder is permitted and a state in which passage of the exhaust air is prevented.

An excavator includes a plurality of hydraulic actuators, and a setting unit that performs a setting related to operation speeds of the plurality of hydraulic actuators during a combined operation of the hydraulic actuators, so that when the operation speed of one of the actuators increases, the operation speed of another one of the actuators decreases. The setting unit is capable of performing the setting for a plurality of kinds of combined operations.

An excavator includes a plurality of hydraulic actuators, and a setting unit that performs a setting related to operation speeds of the plurality of hydraulic actuators during a combined operation of the hydraulic actuators, so that when the operation speed of one of the actuators increases, the operation speed of another one of the actuators decreases. The setting unit is capable of performing the setting for a plurality of kinds of combined operations.

An example valve includes a housing, a sleeve disposed within the housing and having a first end and a second end opposite the first end, and the sleeve includes a plurality of sleeve protrusions at the first end and a plurality of fluid flow channels are formed between adjacent sleeve protrusions, a seal carrier disposed within the sleeve and having a carrier protrusion that extends from the second end of the sleeve and abuts against an interior surface of the housing, and an end cap mounted to the housing such that the plurality of sleeve protrusions abut against the end cap.

A valve for controlling a hydraulic cylinder on a work machine may include a raising position configured for placing a pump in fluid communication with a cap end of the hydraulic cylinder. The valve may also include closed center position configured for closing off fluid communication to the cap end line and the rod end line. The valve may also include a lowering position configured for placing the pump in fluid communication with the rod end of the hydraulic cylinder. The valve may also include a snubbing position configured for placing the cap end in restricted flow fluid communication with the tank and for placing the rod end in restricted flow fluid communication with the tank.

A valve for controlling a hydraulic cylinder on a work machine may include a raising position configured for placing a pump in fluid communication with a cap end of the hydraulic cylinder. The valve may also include closed center position configured for closing off fluid communication to the cap end line and the rod end line. The valve may also include a lowering position configured for placing the pump in fluid communication with the rod end of the hydraulic cylinder. The valve may also include a snubbing position configured for placing the cap end in restricted flow fluid communication with the tank and for placing the rod end in restricted flow fluid communication with the tank.

A hydraulic system, mining machine and method of controlling a hydraulic actuator. The hydraulic system (HS) is provided with a control valve (23) for controlling movement direction and speed of a hydraulic actuator (HA) connected to the system. Generated force of the hydraulic actuator is controlled independently relative to the control valve by means of counterbalance valves (Cb1, Cb2) and servo valves (Sv1, Sv2) controlling their opening pressure. The counterbalance valves and the servo valves operate as a meter-out control assembly which controls flow of hydraulic fluid discharged from working pressure spaces (16a, 16b) of the hydraulic actuator. The disclosed system may be implemented to control a mining boom (3) of a mining machine (1).

A hydraulic power system for a downhole device, including a first motor, a first hydraulic pump, a second hydraulic pump, a first main oil circuit, a second main oil circuit, a switching control module and a first execution module. The first motor has a first output shaft which drives the first hydraulic pump and has an oil outlet connected to an input end of the first main oil circuit and a second output shaft which drives the second hydraulic pump and has an oil outlet connected to an input end of the second main oil circuit; the first execution module is connected to an output end of the first main oil circuit; displacement of the first hydraulic pump is smaller than that of the second hydraulic pump; and the switching control module is connected between the first main oil circuit and the second main oil circuit.