摘要:
A vehicle lift control maintains multiple points of a lift system within the same horizontal plane during vertical movement of the lift engagement structure by synchronizing the movement thereof. A vertical trajectory is compared to actual positions to generate a raise signal. A position synchronization circuit synchronizes the vertical actuation of the moveable lift components by determining a proportional-integral error signal.
摘要:
A flight control surface actuation system is provided in which a plurality of actuators (6-13) are connected to one another in order to synchronize their operation. Each actuator has its own gearbox such that the torque transmitted in the synchronizing element is kept low.
摘要:
The electrohydraulic adjusting device for actuating a device for adjusting at least one camshaft of an internal combustion engine relative to its crankshaft has two differential pistons each of which serves to adjust a camshaft (intake camshaft or exhaust camshaft). Each of the two differential pistons have a small effective piston surface which is acted upon with pressure by a pump. An independent pressure control valve is associated with each of the pressure chambers on a larger effective piston surface, via which valve, the pressure in this pressure chamber can be controlled independently of the other differential piston.
摘要:
A loading crane that can be mounted on a lorry has a jib composed of several arms telescopically nested into each other. A hydraulic unit composed of piston and cylinder is arranged between successive arms. When an arm is extended, a stop arranged on the previous arm actuates a valve entrained with the extended arm, which opens a hydraulic supply for the arm that follows the extended arm. Such valve is arranged at the closed end of a hydraulic cylinder of the arm that follows the extended arm.
摘要:
A self-releveling, height adjustable, hydraulically operated desk and a hydraulic circuit therefor are disclosed in which the desk top is supported for vertical movement upon master and slave rephasing cylinders connected in series. The desk top may be releveled by extending the cylinders to their limits of extension. The desk and circuit may include a height adjustable monitor support. The monitor support may also be supported for vertical movement upon master and slave rephasing cylinders for self-releveling. The hydraulic circuit includes check valves to prevent the desk top and the monitor support from being raised with respect to the supporting structure except upon activation of the hydraulic pump.
摘要:
A large industrial earthmoving machine having a hydraulic propulsion system comprising at least two hydraulic motors which are powered from a source of hydraulic fluid to drive a common load. Each motor of the hydraulic propulsion system is provided with two compensating valve assemblies. Each compensating valve assembly is provided with a compensating spool and a shuttle spool to provide accurate control of the hydraulic motors. In each pair of compensating valve assemblies, there is a forward compensating valve assembly and a backward valve assembly respectively controlling forward and backward movement of the hydraulic motor. Between the both forward compensating valve assemblies and the respective hydraulic motors, the compensating valve assemblies are fluidically coupled to one another by a small hydraulic communication line that better equalizes hydraulic fluid flow to the motors and prevents domination of one forward compensating valve assembly over the other. Similarly, the backward compensating valve assemblies are provided with an identical small hydraulic communication line accomplishing the same results.
摘要:
The invention relates to a method for the simultaneous actuation of a plurality of hydraulic consumers by means of intrinsically-safe electro-hydraulic valves. The consumers are connected by hydraulic directional control valves to a pressure line and/or a return line. These hydraulic directional control valves can be connected in a predetermined manner, via pre-control valves to a control line. The pre-control valves are pressureless, and possess electro-magnets with a current consumption of less than 50 milliamps. By connection of a series-connected electro-hydraulic directional control valve means, the pre-control valves are connected to the control line, and at the same time are hydraulically locked.
摘要:
Apparatus and method for hydraulic actuation via multiple synchronized hydraulic motors with air purging, synchronizing, and force limiting features.
摘要:
A hydraulic system is disclosed which provides automatic proportional actuation of pairs of hydraulic cylinders. The proportioning mechanism comprises one or more standard hydraulic cylinders.
摘要:
A hydraulic flow divider and integrator for operating a plurality of hydraulic loads, in which a plurality of slide valves are each connected between a respective load and a source of pressurized fluid and subjected to hydraulic pressure bias from opposite ends by respective regulating spaces at the opposite ends of each slide valve, the slide valves each having an inlet communicating with the source, and a respective throttle connected between each inlet and a respective one of the regulating spaces of a respective slide valve and functioning to bias the respective slide valve in a valve opening direction, with hydraulic lines communicating between each one of the regulating spaces and the other regulating space of another of the slide valves, whereby a tendency to open one of the slide valves results in a reciprocal tendency to close the other slide valves, and another pressure source independent of the slide valves for pressurizing the one of the regulating spaces of at least one of the slide valves for locking same in an open state.