A balancing valve includes four ports. While the pressures at a pair of balancing ports of a hydraulic balancing valve are equal, the valve maintains two other ports in a closed position. Upon a pressure differential between the balancing ports, fluid communication can occur between one of the balancing ports and either of the other ports based upon the direction of the pressure differential. A hydraulic ride control system utilizes the balancing valve together with other control valves to provide ride control functionality.

The present disclosure provides a hydraulic system for a material handling vehicle. The hydraulic system includes a reservoir tank, a pump configured to draw fluid from the reservoir tank, and an auxiliary circuit having an auxiliary filter. The auxiliary circuit is in fluid communication with one or more auxiliary functions that are configured to receive fluid from the pump and return fluid to the reservoir tank. When the one of the one or more auxiliary functions is commanded, fluid flow is provided from the pump to the reservoir tank through the auxiliary filter.

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 control valve is provided for construction equipment having a holding valve which prevents the natural lowering of an operation apparatus due to the dead weight of the operation apparatus when an actuator is in a neutral position. The control valve includes a valve body, a spool, a holding valve, a control valve, and a pilot pressure control valve. The control valve can save manufacturing cost as well as allow better use of space for construction equipment.

A system for automatically actuating a hydraulic accumulatoruseful for oil collection systemscapable of operation while maintaining a zero or near zero draw of electrical energy.

The invention is directed to controlling a hydraulic actuation system having at least one degree of freedom, a prime mover, at least one actuation module and a controller, with each actuation module including: an over-center variable displacement pump having a power input connection configured to power the pump from the prime mover and a displacement varying input for varying the displacement of the pump; a displacement varying actuator configured to modulate the displacement varying input of the pump; an output actuator in direct communication with the pump, the output actuator configured to drive a corresponding degree of freedom; and at least one sensor establishing a feedback measurement that represents a force or motion of the output actuator. Based on a value of each feedback measurement, the force or motion of the output actuator is regulated by controlling the prime mover and the displacement actuator for the output actuator.

A system for recovering energy from a hydraulic actuator and to a method of operating the system are described. The system may have a hydraulic actuator and a source of hydraulic pressure, comprising a hydraulic pump, in fluid communication with the hydraulic actuator for pressurizing the hydraulic actuator. The system may also have a hydraulic accumulator assembly for selectively absorbing energy from the hydraulic actuator or via the hydraulic actuator. The system may also have a first one-way valve configured to provide fluid communication between the hydraulic actuator and the hydraulic accumulator assembly. The first one-way valve may be configured to permit a flow of fluid through the first one-way valve from the hydraulic actuator to the hydraulic accumulator assembly. The first one-way valve may also be configured to block a flow of fluid through the first one-way valve from the hydraulic accumulator assembly to the hydraulic actuator.

A shovel includes a hydraulic pump, multiple hydraulic actuators, a center bypass oil passage supplied with hydraulic oil discharged from the hydraulic pump, multiple directional control valves, and a bleed-off valve. The directional control valves are arranged in tandem in the center bypass oil passage and configured to supply the hydraulic actuators with the hydraulic oil from the center bypass oil passage. At least a directional control valve other than the most downstream directional control valve in the center bypass oil passage among the directional control valves opens the center bypass oil passage. The bleed-off valve is connected to part of the center bypass oil passage upstream of at least one of the directional control valves.

A hydraulic system for a farm implement includes a wing elevation circuit, a wing folding circuit, and a hydraulic valve block assembly. The wing elevation circuit lowers or raises the wings of the farm implement relative to a frame of the farm implement between a first position, in which the wings extend approximately collinear with a lateral axis of the frame, and a second position, in which the wings extend beneath the lateral axis of the frame. The wing folding circuit folds or unfolds the wings between the first position and a transport position, in which the wings are rotated beyond a vertical axis transverse to the lateral axis. The hydraulic valve block assembly is in communication with the wing elevation circuit and the wing folding circuit and controls hydraulic fluid flow in the wing elevation circuit and in the wing folding circuit.

A system and method configured to direct the braking energy from a high-pressure port at the motor side of a hydraulic circuit to emergency steering, braking, accumulator(s) charging, and/or various work functions. The system and method are also configured to return hydraulic fluid back to the same high-pressure port when the motor is running as a pump.