According to the working condition of the main engine, the power and the working performance of the system, the type of hydraulic pump is determined first, and then the specification and model are determined according to the pressure and flow rate required by the system.

1. For the use of different occasions, the choice of hydraulic pump types are also different. Generally speaking, in the hydraulic system of machine tools, double acting vane pumps and pressure limiting variable vane pumps are often selected, while in road construction machinery, port machinery and small construction machinery, gear pumps with strong anti-pollution ability are often selected, and plunger pumps are often selected when the load is large and the power is large.

2. Please pay attention to whether the flow of the hydraulic pump is adjustable. The hydraulic pump has two kinds of pump and variable pump. The quantitative pump has the advantages of simple structure and low price, and most of the hydraulic systems are often adopted, and the variable pump with high energy utilization ratio also plays a role in an increasing number of occasions.

Generally speaking, if the hydraulic power is less than 10kW, the working cycle is on and off, the hydraulic pump can be completely unloaded when it is not in use, and the hydraulic pump needs to output all the flow under most working conditions, then the quantitative pump can be considered. If the hydraulic power is greater than 10kW, the change of flow rate is more demanding, then the variable pump can be considered. The selection of variable pump variable form can be carried out according to the working condition requirements and control mode of the system.