1. It is strictly prohibited to select hydraulic pumps whose rated operating pressure is less than the larger operating pressure required by the system.

If the hydraulic system only needs to supply the working medium with high pressure and small flow in a short time, the working pressure of the taboo hydraulic pump is the same as that, so it can be selected to be smaller. When selecting the hydraulic pump, it is not appropriate to lower the standard of large hydraulic pump, because when the operating pressure and flow of the hydraulic pump are less than its rated value, the total power of the pump will be reduced.

The larger working pressure marked on the Pelex hydraulic sample is the allowable pressure for a short impact. Stop the impact pressure in each operation cycle, otherwise the service life of the pump will be shortened or even damaged.

2. No special attention was paid to the oil leakage pressure in the hydraulic pump housing.

The oil discharge pressure in the housing depends on the greater pressure allowed by the shaft seal. Excessive oil discharge pressure in the housing will cause premature damage to the shaft seal, transmission oil leakage and other hydraulic pump problems.

Taboo on selection of hydraulic pump flow (displacement)

The flow of the hydraulic pump is related to the working condition, and the larger flow of the hydraulic pump is determined by the larger flow under the system working condition. After the pump displacement is confirmed, the flow is related to the rotational speed of the hydraulic pump of the prime mover.

When the prime mover is connected to the hydraulic pump with a coupling, prevent the speed of the prime mover hydraulic pump from being within the speed range of the operating hydraulic pump; Otherwise, a speed increasing or decelerating device shall be set between the prime mover and the hydraulic pump. The actual flow of the hydraulic pump is equal to the product of the speed of the hydraulic pump and the actual displacement, which should be equal to or slightly greater than the flow calculated in the hydraulic system planning.

Taboo on selecting and improving hydraulic pump power

The greater pressure of the hydraulic pump and the greater speed of the hydraulic pump are prevented from being used at the same time, so as to prolong the service life of the hydraulic pump. The rules in the product manual shall be strictly followed when selecting.

When adjusting the displacement of the variable displacement pump, the higher the pressure and the lower the speed of the hydraulic pump, the lower the volume power and the lower the volume power of the hydraulic pump. When the speed of the hydraulic pump is constant, the total power of the hydraulic pump is higher under a certain pressure, and the total power of the variable displacement pump is higher under a certain displacement and pressure. The total power of the pump has a great influence on the total power of the hydraulic system. Therefore, it is prohibited to select low power hydraulic pumps, but high power hydraulic pumps should be selected, and the hydraulic pumps should be located in the high power operation area as far as possible.

From the perspective of improving energy conversion power, it is prohibited to consider only rated working conditions. The engineers of Paris thought that the volume power of the hydraulic pump was more important than the mechanical power. Because the hydraulic pump can compensate for the loss of mechanical conflict from the prime mover power, the leakage loss in the hydraulic pump cannot be compensated by adding power input.

Taboos for selection and confirmation of hydraulic pump speed

The speed of hydraulic pump is related to the life, cavitation and noise of hydraulic pump. When confirming the speed of the hydraulic pump, there are the following taboos:

Although the allowable speed scale of the hydraulic pump is written on the sample of Pelex Hydraulic, the taboo is to use the hydraulic pump at a better speed that is not suitable for use. When the hydraulic pump is driven by the engine, stop running at low speed when the oil temperature is low, otherwise, it is difficult to absorb oil, and there is a risk of jamming caused by poor lubrication; When the speed of the hydraulic pump is high, the possibility of cavitation, oscillation, abnormal wear, unstable flow and other phenomena should be considered to prevent dramatic changes in the speed of the hydraulic pump from having a significant impact on the strength of the internal parts of the hydraulic pump.

The rotating speed of axial piston pump and motor hydraulic pump shall be selected strictly according to the data specified in Pax product technical specification, and it is prohibited to exceed the larger rotating speed of hydraulic pump.