What Are The Characteristics of The Open System of The Hydraulic Station?

The characteristics of the open hydraulic pump station series system of the hydraulic station:

(1) Generally, dual pumps or three pumps are used for oil supply, and the pilot oil is provided by a separate pilot pump. Some hydraulic actuators require a large amount of power and thus need combined oil supply. There are two ways of combined supply:

Internal flow merging. Usually, two pumps supply oil to a single valve stem. The valve stem controlled by this stem generally controls the oil supply to the required merged hydraulic actuator. The design of the hole diameter of the valve stem for this merging method needs to take into account the flow area occupied by the multiple pump supplies.

2. Valve external convergence. The two pumps operate independently through their respective valve rods, and through the coordinated action of the two valves, they supply oil externally to the required converging hydraulic actuating elements. Although the control structure is relatively complex and the volume is large, this is because the flow passing through the valve rods is that of a single pump, and the diameter of the valve rod holes is relatively small. Moreover, it may be compatible with other valve rods.

(2) Multi-way valves are usually divided into separate sections and each section is supplied with oil by separate pumps. Each valve group can utilize both the direct supply channel and the parallel supply channel for oil supply. The former can achieve priority supply of oil, that is, when the upstream valve stem is actuated, the pressure oil is supplied to the hydraulic components operated by the upstream valve stem, while the hydraulic components operated by the downstream valve stem cannot be actuated. The latter can achieve parallel oil supply.

(3) To meet the requirements of various working conditions and complex actions, simple on-off type two-position two-way valves and cartridge valves are generally used. The oil is directly directed from one oil circuit to another, and a check valve is often employed to prevent oil from flowing back, thus forming a one-way channel.

The operation of the on-off valve can be carried out in the following three ways:

The electromagnetic valve series adopts pilot-operated oil-linked operation. The pilot-operated oil not only controls the movement of the valve stem but also jointly operates the on-off valve.

2. By adding an additional oil passage in the control valve, it becomes possible to use this oil passage as the control oil passage for the on-off valve. Thus, while operating the control valve, the opening and closing of the on-off valve can also be controlled.

Another drawback of the open oil circuit in the hydraulic station is that when one pump supplies multiple actuators to operate simultaneously, since the hydraulic oil flows to the actuator with the lighter load first, it causes the actuator with the heavier load to have difficulty in operating. Therefore, it is necessary to throttle the control valve stem of the actuator with the lighter load.