Our common hydraulic pump failure analysis and countermeasures, water pump technology experts have been advocating to provide users with product analysis and answers to problems in use, and let everyone understand the truth, and finally let users know how to solve the hydraulic pump troubleshooting , The following is a common failure analysis and response strategy. [FY series submerged pump]

1. Find the cause of the fault from the following three points during maintenance and improve the system:

Check the internal leakage of the boom cylinder. The easiest way is to raise the boom to see if it has a clear free fall. If the drop is obvious, remove the cylinder and check. If the seal ring is worn, it should be replaced.

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

Measure the pressure of the hydraulic pump. If the pressure is low, adjust it, but the pressure can not be adjusted, it means that the hydraulic pump is seriously worn.

Generally speaking, the main reasons that cause the boom loading cannot be improved are:

A. The hydraulic system design is unreasonable. The control valve and the full hydraulic steering gear are connected in series by a single pump. The set pressure of the safety valve is 16MPa, and the rated working pressure of the hydraulic pump is also 16MPa. Hydraulic pumps often work under full load or long-term overload (high pressure) conditions, and the system has hydraulic impact, no oil change for a long time, the hydraulic oil is contaminated, the hydraulic pump wear is aggravated, so that the pump casing of the hydraulic pump burst (later found Such failures).

B. 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 seals are inconvenient to replace. The small diameter of the boom cylinder will inevitably make the system set pressure high.

C. The hydraulic pump is badly worn. During low-speed operation, the internal leakage of the pump is serious; during high-speed operation, 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. Long-term operation of the hydraulic pump has intensified the wear and the temperature of the oil has increased, which has caused the wear of the hydraulic components and the aging and damage of the seals, the loss of sealing ability, the deterioration of the hydraulic oil, and finally the failure.

2. Improvement and effect

During the use process, attention should also be paid to the correct use and maintenance of the loader, the hydraulic oil should be regularly added or replaced, the cleanliness of the hydraulic oil should be maintained, and the daily inspection and maintenance should be strengthened.

Optimize the design of boom cylinder and hydraulic pump to reduce the working pressure of the system. Through optimization calculation, the boom cylinder adopts the standard series 80/4. The displacement of the hydraulic pump is increased from 10ml/r to 14ml/r, and the system setting pressure is 14MPa, which meets the lifting force and speed requirements of the boom cylinder.

Improve hydraulic system design. After many demonstrations, the advanced priority valve and load sensing full hydraulic steering gear are finally adopted, as shown in Figure 2. The new system can give priority to the flow according to the steering requirements. No matter the load size or the steering wheel speed, it can ensure sufficient oil supply, and the remaining part can be fully supplied to the working device circuit, thereby eliminating the power caused by the excessive oil supply to the steering circuit. Loss improves the efficiency of the system and reduces the working pressure of the hydraulic pump.