The invention relates to an actuator device comprising at least one output element, which can be applied with a fluid and can thereby be moved into at least one retaining position. An actuator is provided which can be operated in a pumping operation by controlling the actuator, in which at least one part of the actuator can be alternatingly moved in a first direction and in a second direction opposite the first direction via the controlling of the actuator, whereby the fluid can be conveyed to the output element in order to apply the output element with the fluid. A discharge channel is also provided, via which the fluid can be discharged from the output element.

Disclosed is a hydraulic pilot valve which is provided with an orifice so as to reduce vibration of a valve and minimize impact applied to a valve even when a valve is suddenly operated. At least some of hydraulic oil supplied to a supply chamber flows to a valve chamber or a central pipeline through a damping unit according to elevation of a spool.

Disclosed is a hydraulic pilot valve which is provided with an orifice so as to reduce vibration of a valve and minimize impact applied to a valve even when a valve is suddenly operated. At least some of hydraulic oil supplied to a supply chamber flows to a valve chamber or a central pipeline through a damping unit according to elevation of a spool.

A hydraulic control system includes a first hydraulic cylinder, a second hydraulic cylinder, a fluid supply apparatus, a first control valve bank, a second control valve bank, a third control valve bank, and a first check valve. The first control valve bank is configured to independently control the first hydraulic cylinder; the second control valve bank is configured to independently control the second hydraulic cylinder; and the third control valve bank is configured to synchronously control the first hydraulic cylinder and the second hydraulic cylinder. Synchronous volume control is implemented through series connection of the hydraulic cylinders, and has quite high synchronization precision, which is measured to be up to two percent.

A system for adjusting actuator pressure on an agricultural implement includes a fluid-driven actuator configured to adjust a position of a tool of the implement relative to the implement frame, with the fluid-driven actuator defining a fluid chamber. Furthermore, the system includes a valve configured to control a flow of a fluid to the fluid-driven actuator. In addition, the system includes a fluid conduit fluidly coupled between the valve and the fluid chamber. Moreover, the system includes a computing system is configured to determine the current position of the tool relative to the implement frame based on the data captured by a position sensor. Additionally, the computing system is configured to determine a current volume of the fluid chamber and the fluid conduit based on the determined current position. Furthermore, the computing system is configured to control the operation of the valve based on the determined current volume.

A pump control assembly for controlling a variable displacement hydraulic pump includes a spool mounted within a valve block. The spool is configured to move between a first and a second position within the valve block so as to selectively control the displacement of the attached pump. The pump control assembly further includes first and second chambers that each apply a force to opposite ends of the spool. The first chamber is positioned at a first end of the spool in fluid communication with a pump output port. The second chamber is positioned at a second end of the spool and in fluid communication with a hydraulic tank port and a proportional pressure reducing valve. The second chamber also includes a piston and first and second springs positioned on either side of the piston. The proportional pressure reducing valve provides a regulated pressure to a first side of the piston along with the first spring, and the hydraulic tank port provides a tank pressure on the opposite side of the piston along with the second spring. The pump control assembly also includes a stop structure having a positive stop that limits movement of the piston in a direction toward the first chamber.

A lift system includes a lift structure and a lift structure actuation assembly. The lift structure can actuate between a lowered position and a raised position. The lift structure actuation assembly includes a hydraulic cylinder operably coupled with the lift structure, a motor, a hydraulic pump powered by the motor, and a flow control assembly that can limit hydraulic fluid exiting the hydraulic cylinder to a maximum volumetric flow rate. The hydraulic pump can pump hydraulic fluid into the hydraulic cylinder in order to raise the lift structure. The lift structure actuation assembly can lower the lift structure in a fast descent mode and a slow decent mode. In the slow descent mode, the hydraulic pump pumps hydraulic fluid toward the hydraulic cylinder such that the hydraulic fluid exits the hydraulic cylinder at a slower volumetric flow rate compared to the maximum volumetric flow rate.

A lift system includes a lift structure and a lift structure actuation assembly. The lift structure can actuate between a lowered position and a raised position. The lift structure actuation assembly includes a hydraulic cylinder operably coupled with the lift structure, a motor, a hydraulic pump powered by the motor, and a flow control assembly that can limit hydraulic fluid exiting the hydraulic cylinder to a maximum volumetric flow rate. The hydraulic pump can pump hydraulic fluid into the hydraulic cylinder in order to raise the lift structure. The lift structure actuation assembly can lower the lift structure in a fast descent mode and a slow decent mode. In the slow descent mode, the hydraulic pump pumps hydraulic fluid toward the hydraulic cylinder such that the hydraulic fluid exits the hydraulic cylinder at a slower volumetric flow rate compared to the maximum volumetric flow rate.

An aircraft store ejector systems and subsystems thereof. Embodiments can include a two-reservoir re-pressurization system wherein a remote reservoir is used to maintain desired pressure in a local ejector reservoir. The system can include a release valve having a vent valve and valve piston. The release valve can control release of pressurized gas to a pitch control valve. The pitch control valve can be configured to distribute the pressurized gas between two or more ejector piston assemblies. One or more of the ejector piston assemblies can include multiple concentric piston stages and piston chambers, the piston chambers configured to contain a volume of gas. The ejector piston assemblies can be configured to compress the volume of gas within the piston chambers as the piston stages are extended out from the aircraft. Such compression can provide a return force to the piston stages.

A coupler cylinder is driven between a locked state and an unlocked state of a bucket by being supplied with hydraulic oil. A main pump supplies the hydraulic oil to the coupler cylinder. A pressure increasing valve controls the supply of the hydraulic oil to the coupler cylinder. A controller controls drive of the pressure increasing valve. The controller instructs the pressure increasing valve to stop the supply of the hydraulic oil to the coupler cylinder based on pressure in an oil passage between the main pump and the coupler cylinder.