How to analyze the cause of the failure phenomenon of the vane pump?

After the vane pump has been used for a long time, some accidents will generally occur. So what are the most common vane pump failures? How to analyze the cause of the failure? Next, I will give you a detailed talk about the cause analysis of the failure phenomenon of the vane pump and the answer to the improvement effect as follows:

Fault phenomenon and cause analysis of vane pump

1.Check the internal leakage of the boom cylinder. The easiest way is to raise the boom and see if it has an obvious free fall. If the drop is obvious, disassemble the oil cylinder for inspection, and replace the sealing ring if it is worn;

2.Check the control valve. First clean the safety valve, check whether the spool is worn, and replace it if worn. If there is still no change after the safety valve is installed, check the wear of the control valve spool again. The clearance limit is generally 0.06mm, and it should be replaced if the wear is serious;

3.Measure the pressure of the hydraulic pump. If the pressure is low, adjust it, if the pressure is still not adjusted, it means that the hydraulic pump is seriously worn.

Generally speaking, the main reasons why the vane pump boom cannot be lifted with load are:

1.The hydraulic pump is severely worn. When the pump is running at low speed, the leakage is serious; when it is running at high speed, the pump pressure is slightly increased, but due to the wear and internal leakage of the pump, the volumetric efficiency is significantly reduced, and it is difficult to reach the rated pressure. The long-time working of the hydraulic pump will increase the wear and tear, and the oil temperature will rise, which will cause the wear of the hydraulic components and the aging and damage of the seals, loss of sealing ability, deterioration of the hydraulic oil, and finally lead to failure;

2.The selection of hydraulic components is unreasonable. The specifications of the boom cylinder are 70/40 non-standard series, and the seals are also non-standard parts. The manufacturing cost is high and the replacement of the seals is inconvenient. The bore of the boom cylinder is small, which will inevitably make the system set pressure high;

3.The design of the vane pump system is unreasonable. It can be seen from Figure 1 that the control valve and the full hydraulic steering gear are connected in series with a single pump, the setting pressure of the safety valve is 16MPa, and the rated working pressure of the hydraulic pump is also 16MPa. The hydraulic pump often works under the condition of full load or long-term overload (high pressure), and the system has a hydraulic impact. If the oil is not changed for a long time, the hydraulic oil will be polluted, which will aggravate the wear of the hydraulic pump, so that the hydraulic pump casing will burst (it was discovered later that such failures).