Causes of failure in vane pump maintenance during hydraulic pump maintenance

The causes of vane pump failures during hydraulic pump maintenance are generally reflected in: loud noise, pressure oscillation, system pressure loss, no pressure, system oil temperature is too high, etc.

1. The vane pump has no pressure

No pressure means that there is no pressure in the system when the vane pump is working. First, check whether the hydraulic oil is discharged from the vane pump. If not, check whether the working direction of the oil pump is correct and whether the coupling connection between the motor and the vane pump is normal. , whether the shaft positioning screw is tightened and functional, and whether the blades cannot work normally due to the high viscosity of the hydraulic oil; if there is hydraulic oil coming out, it proves that the pump is basically fine. The problem should be a serious leakage of the control valve and the total pressure valve. (Relief valve) failed.

2. Oil temperature is too high

The reason why the system oil temperature is too high should be that the system pipes are too small, the pressure is too high, the cooling system does not meet the requirements, etc., which leads to oil trapping in the vane pump, which is reflected in the pump body and system oil temperature being too high. Increase the system pressure according to the actual situation. pipeline, or reduce the displacement of the pump (replace a small-displacement pump core), and adjust the cooling system to increase the cooling effect.

3. Pressure oscillation

Pressure oscillation means that the pressure of the system is unstable when the vane pump is working. As long as there is no abnormal noise from the oil pump, it should be a problem with the total pressure valve (relief valve). Check whether the spool of the total pressure valve is worn. Check whether the damping is blocked by foreign matter; if the pressure oscillates due to wear of the pump core components, there will be abnormal noise when the oil pump is working.

4. Vane pump loses pressure

System pressure drop means that the vane pump can reach a predetermined pressure when working, but the pressure will gradually drop, causing the system to fail to work normally. If this phenomenon occurs in a newly installed pump, it should be caused by leakage of the system control valve or excessive oil temperature. If the above problem occurs again after a period of use, it is necessary to check whether the upper and lower oil distribution plates are worn (very smooth Wear), if the gap between the upper and lower oil distribution plates is too large, the oil temperature is too high (the mucosa cannot form a self-sealing oil), and leakage of the control valve will cause the system to lose pressure.