Selection of hydraulic components in hydraulic system design

1. Selection of hydraulic pump

The specifications and models of hydraulic pump are selected according to the calculated value in the product sample, in order to make the hydraulic pump work safely and reliably, the hydraulic pump should have a certain amount of pressure reserve, usually the rated pressure of the pump is 25% - 60% higher than the working pressure. The rated flow of the pump should be comparable, not more than too much, so as not to cause excessive power loss.

2. Selection of flow valve

When selecting the throttle valve and speed regulating valve, it is also necessary to consider whether the minimum stable flow rate meets the design requirements, and the minimum stable flow rate of the general medium and low pressure flow valve is 50ml/min~100ml/min; The minimum stable flow rate of the high-pressure flow valve is 2.5ml/min to 20ml/min.

3. The choice of relief valve

Direct action relief valve response is fast, suitable for brake valve and flow small safety valve, pilot relief valve opening and closing characteristics are good, should be used as pressure regulator, back pressure valve and flow large safety valve.

The minimum setting pressure of the pilot relief valve can generally only be in the range of 0.5~1Mpa. When selecting the relief valve, it should be selected according to the maximum flow of the hydraulic pump, and should pay attention to the minimum stable flow allowed, in general, the minimum stable flow should be more than 15% of the nominal flow.

4. Selection of check valve and hydraulic control check valve

When selecting a check valve, attention should be paid to its opening pressure, the opening pressure is small as a check valve, and the opening pressure is large.

The hydraulic control check valve is divided into internal leakage type and external leakage type. The control pressure of external leakage type is low, and the work is reliable, but there is more than one oil drain pipe.

5. Selection of reversing valve

Choose the structure type according to the flow rate, when the general flow rate is above 190L/min, it is appropriate to choose the two-way cartridge valve, and the electromagnetic reversing valve can be used below 70L/min, otherwise the electro-hydraulic reversing valve is required.

Select the type of electromagnet according to the reversing performance, because the DC electromagnet, especially the DC wet electromagnet, has a long life and high reliability, so the DC wet electromagnetic reversing valve should be selected as far as possible.

Select slide valve function according to system requirements. For systems with particularly high reliability requirements, the rated pressure of the valve element should be much higher than its working pressure.

6. Choice of tubing

The specification size of the tubing is mostly determined by the size of the connected hydraulic component interface, and the inner diameter and wall thickness are only checked for some important pipelines.

For fixed hydraulic equipment, the power source and valve components of the hydraulic system are often centrally installed on the hydraulic station outside the main engine, which can make installation and maintenance convenient, and eliminate the influence of vibration and oil temperature changes of the power source on the working accuracy of the main engine.