Disclosed embodiments of power machines, implements and hydraulic systems utilize a hydraulic flow control circuit and method to implement multiple modes of operation while optimizing hydraulic fluid flow to either or both of primary and secondary function actuators. In a first mode the hydraulic flow control circuit is configured to receive pressurized hydraulic fluid flow from a first conduit and to provide the pressurized hydraulic fluid to the primary and secondary function actuators. In the first mode, the circuit is configured to direct return flow from the primary and secondary function actuators through the second conduit for return to the power machine. In a second mode, the circuit receives flow from the second conduit, provides the flow only to the secondary function actuator, and directs the return flow to the power machine through the first conduit.

An electropneumatic positioner for a pneumatic actuator to operate a control device of a processing plant can include two modular pneumatic slots and a pneumatic control output. The two modular pneumatic slots can engage with a respective modular pneumatic component. The two pneumatic slots and the pneumatic components can be modularly matched to one another such that their respective pneumatic interfaces merge into one another when a pneumatic slot is engaged. The pneumatic control output can output a pneumatic control pressure signal to the pneumatic actuator. The two modular pneumatic slots and the pneumatic control output can form a pneumatic series connection.

A hydraulic control system includes a variable displacement hydraulic pump, the pump having an inlet for receiving fluid, an outlet for discharging fluid under pressure, and a pump displacement input, a hydraulic motor having an inlet and an outlet a fluid circuit including a supply conduit for conducting fluid discharged by the pump to the motor and a return conduit for returning fluid discharged by the motor to the pump, a pump displacement control cooperating with the pump displacement input in order to vary a displacement of the pump, a control circuit in communication with the pump displacement control for controlling the pump output such that the motor is driven at a constant rotational speed and at least two valves controlling a rotational speed of the motor, wherein one of the valves provides coarser flow control resolution and another of the valves provides finer flow control resolution.

A method for operating a pneumatic actuating system of a transmission. The actuating system has an air reservoir at a first pressure. The reservoir couples an actuating space of the actuating system which is at a second pressure, and the actuating space couples, via control valves, shifting cylinders. When conducting a transmission gearshift, an air mass delivered to the active shifting cylinders via corresponding control valves, and an air mass sum including a nominal air mass in the active cylinders required for accomplishing the gearshift and an actual basic leakage from the activated shifting cylinder are determined. A defect leak in the pneumatic actuating system is recognized, if the air mass delivered to the active shifting cylinders is larger than the air mass sum. If a defect leak is recognized, the control valves coupling the actuating space and the shifting cylinders are shut off for a period of time.

A hydraulic system for a working machine includes a hydraulic pump, a first hydraulic actuator, a second hydraulic actuator, a first control valve to control the first hydraulic actuator, a second control valve to control the second hydraulic actuator, and a discharge fluid tube in which the operation fluid flows. The discharge fluid tube is connected to the first control valve. The hydraulic system includes a first fluid tube in which a return fluid flows toward the second control valve. The first fluid tube couples the first control valve to the second control valve. The hydraulic system includes a second fluid tube coupling the first fluid tube and the discharge fluid tube, a first throttle disposed on the first fluid tube, and a second throttle disposed on the second fluid tube, the second throttle having an opening area smaller than an opening area of the first throttle.

Transportable inline heave compensator provided with connection devices for suspending the compensator from a load bearing device and a connection device for a carrying a payload, where the compensator comprises a passive heave compensator part and possibly an active heave compensator part, and being provided with a sensor arrangement, where the compensator further comprises at least one actuator, that is horizontally oriented in operation and comprises an actuator piston rod with a horizontally stroke indirectly connected to a rope means, where the rope means at an end, via a connection device, such as a padeye, is connected to at least one of; a vessel at the sea surface or a payload, incorporating a device with a curved surface where rope means is suspended to for converting the vertical movements of vessel or payload to horizontal movements of the actuator piston rod compensating the load.

A method of controlling hydraulic fluid flow to an implement of a material handling vehicle includes coupling a boom arm to a vehicle frame for rotation about the vehicle frame, rotating a boom arm with respect to the vehicle frame with an actuator, coupling an attachment to the boom arm for rotation with respect to the boom arm, sensing a pressure of fluid in the actuator, communicating the sensed pressure to a control system, determining a baseline pressure of the attachment based upon the sensed pressure of the fluid in the actuator, and limiting fluid flow to the actuator with a control valve in response to the sensed pressure of the fluid in the actuator being above the baseline pressure.

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 cylinder driving device includes: an electric motor; a pump; a main passage and a main passage; a hydraulic cylinder; an operation check valve and an operation check valve; and a restriction valve and a restriction valve configured to restrict a flow of the working oil directed to the operation check valve and an operation check valve, wherein an opening area of the restriction valve and the restriction valve is reduced in response to an increase in a flow rate of the working oil discharged from the hydraulic cylinder to the main passage and a main passage.

The present invention relates to a work machine having at least one hydraulic actuator for actuating a piece of working equipment and having a first displacement unit that is driven by a drive assembly of the work machine and that feeds the hydraulic actuator with hydraulic medium from a hydraulic tank, wherein at least one second displacement unit is provided that is driven by the drive assembly and that feeds the hydraulic actuator and/or further hydraulic consumers with hydraulic medium from a hydraulic tank in the working mode and that is drivable during a recovery mode by the hydraulic volume displaced by the at least one hydraulic actuator or by a hydraulic consumer to feed kinetic energy back to the drive assembly.