Patent classifications
F15B2211/315
FLUID POWER CONTROL SYSTEM FOR MOBILE LOAD HANDLING EQUIPMENT
A fluid power control system for load handling mobile equipment includes a pair of hydraulic actuators for moving respective cooperating load-engaging members selectively toward or away from each other, or in a common direction, at respective asynchronous speeds to selectively attain either synchronous or asynchronous respective positions of the actuators. The actuators have sensors enabling a controller to monitor their respective movements and correct unintended differences in the actuators' respective movements, such as unintended differences in relative intended positions, speeds, or rates of change of speeds. Respective hydraulic valves responsive to the controller separately and nonsimultaneously decrease respective flows through the respective actuators to more accurately and rapidly correct differences from the intended relative movements of the actuators.
Fluid power control system for mobile load handling equipment
A fluid power control system for load handling mobile equipment includes a pair of hydraulic actuators for moving respective cooperating load-engaging members selectively toward or away from each other, or in a common direction, at respective asynchronous speeds to selectively attain either synchronous or asynchronous respective positions of the actuators. The actuators have sensors enabling a controller to monitor their respective movements and correct unintended differences in the actuators' respective movements, such as unintended differences in relative intended positions, speeds, or rates of change of speeds. Respective hydraulic valves responsive to the controller separately and nonsimultaneously decrease respective flows through the respective actuators to more accurately and rapidly correct differences from the intended relative movements of the actuators.
Control Valve and Work Vehicle Having the Control Valve
An inner oil passage (45) is formed inside a slidable spool (22). The slidable spool (22) defines, in its circumferential face, a first opening (46), a second opening (47) and a third opening (48). The first opening (46), the second opening (47) and the third opening (48) are communicated to the inner oil passage (45). When the slidable spool (22) is switched to a floating position (F), the first the first opening (46) is aligned with a first port end portion (25a), the second opening (47) is aligned with a second port end portion (26a), and the third opening (48) is aligned with a fourth port end portion (24a), respectively, and a first cylinder port and a second cylinder port are communicated to a tank port (24) via the inner oil passage (45).
VALVE FOR ELECTROHYDROSTATIC ACTUATOR
An electrohydrostatic actuator, comprising an actuator for driving a component, a pump configured to pump hydraulic fluid for operation of the actuator, and a control valve for controlling passage of the hydraulic fluid between the actuator and the pump, wherein the control valve is movable between first and second positions. In the first position the control valve is configured to convey hydraulic fluid from the pump through the control valve for operation of the actuator, and in the second position the control valve is configured to fluidly disconnect the pump and the actuator, and circulate hydraulic fluid arriving from the pump back to the pump via a first constriction within the control valve.