An automatic oil return structure is provided. The automatic oil return structure has an oil storage bag, a piston, and a main body assembly. The piston has an oil storage chamber. The main body assembly has a main channel, a piston oil channel, a pressure regulating channel, a control channel, an operation channel, a minor channel, and an oil return channel. When the pressure of the main channel achieves a limit pressure, the pressure pushes the control blocking assembly away such that the pressure regulating channel communicates with the communication channel, and the pressure also pushes the operating assembly away such that the minor channel communicates with the return channel. At the same time, the pressure of the oil storage chamber pushes the oil blocking assembly, so as to isolate the oil storage chamber from the main channel, and the oil storage chamber communicates with the oil return channel.

A hydraulic fluid control valve (HFCV) configured to recirculate an exiting hydraulic fluid from a first hydraulic actuation chamber to a second hydraulic actuation chamber is provided. The HFCV includes a selectively movable spool having an inner fluid chamber configured to receive and deliver the exiting hydraulic fluid to one or both of either a sump or one of the first or second hydraulic actuation chambers.

The present invention relates to a valve block, for at least one valve, in particular a slip-in valve having at least one cavity for receiving the valve; a first opening for inlet of a fluid and a second opening for outlet of the fluid, wherein the openings open into the cavity; a mounting area in which the openings are provided; and a collar for securing the valve, which collar extends at least in sections around the cavity, wherein the collar integrally formed with the valve block by primary shaping, in particular injection molding or die casting.

A solenoid valve system includes a supply solenoid valve, a plurality of exhaust solenoid valves, and a valve control section controlling opening and closing operation of the supply solenoid valve and the plurality of exhaust solenoid valves using PWM or PFM. The plurality of exhaust solenoid valves are disposed in parallel with each other. The supply solenoid valve and the plurality of exhaust solenoid valves have substantially identical flow rate characteristics. The number of the plurality of the exhaust solenoid valves is twice the number of the supply solenoid valve.

A hydraulic valve assembly having a regeneration circuit, where the hydraulic valve assembly is switchable between a regenerative mode and a non-regenerative mode as the valve assembly supplies fluid to operate a hydraulic device. The hydraulic valve assembly may be automatically switchable between the regenerative mode and the non-regenerative mode, such as by utilizing a pressure control valve in the hydraulic circuit that is activatable at a predetermined pressure setpoint, or by utilizing a variable pressure reducing valve that actuates a spool in the hydraulic circuit. In other embodiments, the hydraulic valve assembly may be manually switchable between the regenerative mode and non-regenerative mode by utilizing a valve member operatively coupled to a solenoid in cooperation with one or more check valves in the regeneration circuit.

A valve, which is characterized in that between a neutral position (38) of a control spool (STS) and one of its end positions (34, 42) a regeneration position (36) is provided. In the regeneration position, two utility ports (A, B) are interconnected in a fluid-conveying manner, or a floating position (40) is provided, in which these utility ports (A, B) are interconnected in a fluid-conveying manner. A further valve is characterized in that by a further motion of the control spool (STS) in the same direction, as that, in which a fluid connection is established between the utility ports (A, B) starting from the neutral position (38), this fluid connection is interrupted.

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 hydraulic system for a working machine includes a hydraulic actuator configured to be operated by operation fluid, a control valve connected to the hydraulic actuator, and a communication fluid line for fluid communication between the hydraulic actuator and the control valve. The control valve includes a first supply path to guide the operation fluid toward the hydraulic actuator; a regeneration path to guide the operation fluid having been returned to the control valve from the hydraulic actuator, to the first supply path; and a branched path that branches from the regeneration path and supplies operation fluid to outside of the control valve.

A header assembly for an agricultural harvesting machine comprises a first frame assembly, a second frame assembly that supports a cutter, and is movable relative to the first frame assembly, a float cylinder coupled between the first frame assembly and the second frame assembly, an accumulator, a controllable reservoir, and fluidic circuitry. The fluidic circuitry comprises a first conduit forming a first fluid path that provides a flow of pressurized fluid under pressure to the float cylinder, so the float cylinder exerts a float force on the second frame assembly, a valve mechanism that is actuatable to inhibit fluid flow along the first fluid path between the accumulator and the float cylinder, a second conduit forming a second fluid path fluidically coupled to the controllable reservoir, the controllable reservoir being controllable to add fluid to the float cylinder.

One object is to reduce a weight of a fluid actuator. The fluid actuator includes: a cylinder having an inner space and a first mounting portion, the inner space being partitioned into a first fluid chamber and a second fluid chamber, the first mounting portion being disposed on an end portion of the cylinder on an axial direction A side; and a piston rod configured to reciprocate in accordance with pressures in the fluid chambers. A wall portion defining the first fluid chamber in the cylinder is made of an iron-based alloy. A wall portion defining the second fluid chamber in the cylinder is made of an aluminum alloy. The piston rod is made of an iron-based alloy.