Answers to common problems encountered in the use of hydraulic oil pumps

1. The hydraulic pump has metal knocking sound, what is the situation?

When you hear the metal tapping sound of the hydraulic pump oil, you should suspect that there may be mechanical damage inside the hydraulic pump, and stop the pump immediately.  

(1) Remove the hydraulic oil return filter element; the oil suction filter element; and the pilot filter element; check whether there is any metallic substance, and judge the cause of the failure according to the shape, size and material of the metallic substance;

(2) Return to the hydraulic pump manufacturer for after-sales service, and disassemble it for inspection and maintenance by professionals.

2. What is the relationship between the hydraulic pump and the pressure when adjusting the flow?

(1) When a quantitative pump (displacement is not variable) is used and the pressure control valve is not connected to the cylinder load in series, as long as the pump speed remains unchanged, the theoretical pump pressure depends on the load pressure (of course, the load pressure cannot exceed The set pressure of the main safety valve of the system cannot exceed the rated pressure of the pump), so the output flow of the pump will not change due to changes in pressure.

(2) When using a variable pump (variable displacement) without connecting the pressure control valve in series with the cylinder load, as long as a load sensing system or a power control system is adopted in your hydraulic control system, then the load pressure is relatively small. , The output flow of the pump is generally large. On this basis, the larger the load, the smaller the output flow of the pump, that is, the pressure and the flow are inversely proportional, depending on the pressure-flow characteristic curve (there is a correlation in the hydraulic pump sample data). material).

3. The reason why the pressure of the hydraulic plunger pump cannot go up and the plunger pump has no pressure?

The pressure problem of the hydraulic plunger pump involves many problems. It is necessary to check the oil distribution plate, plunger, cylinder block, internal leakage and other aspects. It is recommended to have remote technical support or on-site inspection by a professional hydraulic pump maintenance engineer.

5. Rexroth hydraulic pump selection manual, how to choose Rexroth hydraulic pump model?

Whether it is Rexroth or Parker, Vickers and other brand hydraulic pumps, it is recommended to refer to the original hydraulic pump parameters of mechanical equipment, and then fine-tune it according to actual needs. Under normal circumstances, Palix does not provide hydraulic selection services for major brands, because the actual needs of each hydraulic system and equipment are different, and there is no standard for reference.

6. What is the operating temperature of the Vickers plunger pump?

Whether it is a Vickers plunger pump or other brand hydraulic pumps, it needs to meet a certain temperature if it wants to be normal or not to damage the service life. Under normal circumstances, in order to protect the durability of the Vickers plunger pump and valve, it is forbidden to start the oil in the Wendy area of ​​15 degrees.

7. How does the hydraulic oil pump exhaust air?

In the daily operation and use of hydraulic oil pump, air will inevitably enter, resulting in cavitation. The phenomenon of cavitation and cavitation deteriorates the working performance of the hydraulic oil pump and reduces the reliability. The damage is the same as the hydraulic shock, and the damage to the hydraulic components is more serious.