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.

The subject matter of this specification can be embodied in, among other things, a position sensor system that includes a sensor housing defining a first cavity having a first face, a fluid effector including an actuator housing having an inner surface defining a second cavity, and a moveable body having a second face and configured for reciprocal movement within the second cavity, an acoustic transmitter system configured to emit a first emitted acoustic waveform toward the first face, and emit a second emitted acoustic waveform toward the second face, and an acoustic receiver system configured to detect a first reflected acoustic waveform based on a first reflection of the first emitted acoustic waveform based on the first face, and detect a second reflected acoustic waveform based on a second reflection of the second emitted acoustic waveform based on the second face.

A harvesting system includes a header pivotally attached to a combine. The header includes a center section to which a left wing and right wing are pivotally attached. A suspension system of the harvesting system includes first and second engageable states that enable dynamic wing behavior and reduce structural load. The first state corresponds to a harvesting configuration of the header in which the wings are allowed to pivot to allow the header to follow changes in terrain. The second state corresponds to a configuration in which the header is elevated relative to the ground. In the second state, the ability of the wings to pivot is minimized as compared to the first state, which allows the header to be maintained in a substantially flat configuration while minimizing the amount of dynamic load imparted by the header on the combine during non-harvesting transport of the header.

The present invention provides an engineering machinery hydraulic system with compensation differential pressure controllable, uses an electronic pressure compensating valve to solve the problem of flow mismatch under conditions of pressure over-limit and flow saturation, and realizes proportional shunt control and high-precision flow distribution of the system. The engineering machinery hydraulic system disclosed in the present invention has the advantages of low energy consumption, fast response speed, and high flow control precision.

A harvesting system includes a header pivotally attached to a combine. The header includes a center section to which a left wing and right wing are pivotally attached. A suspension system of the harvesting system includes first and second engageable states that enable dynamic wing behavior and reduce structural load. The first state corresponds to a harvesting configuration of the header in which the wings are allowed to pivot to allow the header to follow changes in terrain. The second state corresponds to a configuration in which the header is elevated relative to the ground. In the second state, the ability of the wings to pivot is minimized as compared to the first state, which allows the header to be maintained in a substantially flat configuration while minimizing the amount of dynamic load imparted by the header on the combine during non-harvesting transport of the header.

A failsafe vale provides “Hole-In-The-Wall” failsafe functionality for thin-wing aircraft control surface actuation systems having a geared rotary actuator powered by a hydraulic rotary motor. The failsafe valve is associated with the hydraulic rotary motor and mechanically connected to the control surface, and enables the flight control surface to return to an aerodynamically neutral failsafe position if electrical control and/or hydraulic pressure is lost. When the failsafe valve receives a normal command pressure from the hydraulic system, the valve is inactive and the actuation system operates normally. However, if there is a loss of electrical command capacity to control hydraulic valves and/or a loss of hydraulic pressure, the failsafe valve is activated and connects one of the motor hydraulic control lines to the case return line for the motor if the control surface is away from its failsafe position. Consequently, the control surface will be hydraulically powered or aerodynamically ratcheted to its failsafe position in the failure event.

A pressure regulator includes an outlet pressure sensor, loading and unloading electromagnetic valves, and a regulator control circuit operatively connected to the loading and unloading electromagnetic valves and configured to pilot the loading and unloading electromagnetic valves to cancel an error signal given by a difference between an inlet signal corresponding to a desired outlet pressure and a feedback signal provided by the outlet pressure sensor. The pressure regulator includes an engaging current analysis circuit to detect and store reference characteristics of the engaging current of the solenoid of the loading electromagnetic valve in a stable inlet pressure condition, monitor the engaging current to detect any variation of its characteristics with respect to the corresponding reference characteristics, and, in the event of variation, provide a pilot modulation signal to at least one of the loading or unloading electromagnetic valves or a pressure variation signal to the regulator control circuit.

A construction machine that precisely enables derivation of the operation characteristics of hydraulic actuators in a high-velocity area with less calibration operation is provided. A controller (10) has a calibration mode in which the controller (10) derives operation characteristics (α(xs)) representing a relation among a spool position (xs) of a meter-in valve (8a1), an operation velocity (Va) of a hydraulic actuator (4a), and a differential pressure (ΔP) across the meter-in valve (8a1), and is configured to, in a case where the spool position (xs) of the meter-in valve (8a1) has changed in a direction to increase the opening area of the meter-in valve (8a1) in the calibration mode, output a command signal to increase the opening area of a bleed-off valve (8b1) to a bleed-off solenoid proportional pressure-reducing valve (8b2) as a command signal to reduce the differential pressure (ΔP).

This disclosure includes systems and methods for actuating hydraulically-actuated devices.

The present invention discloses a load-sensing multi-way valve with a variable differential pressure, where each valve group uses a new element: an electro-hydraulic pressure compensation valve, so as to implement continuous real-time adjustment and control of compensated differential pressure and real-time position feedback and monitoring of a compensation valve trim, and overcome a flow mismatch problem of a conventional LS system in a flow saturation working condition and problems of a fixed shunting proportion of an LUDV system and poor operation coordination of actuators. The load-sensing multi-way valve with a variable differential pressure disclosed in the present invention has advantages such as strong working condition applicability, high flow distribution accuracy, and strong technicality.