1, reliability problem (life and stability);

(1) Domestic components are of poor quality and unstable. (2) The design level is low and the system is not perfect.

2. Vibration and noise;

(1) There is gas in the system, which has not been discharged.

(2) The oil suction pipe is poorly sealed and sucks air.

(3) High system pressure.

(4) unreasonable fixing of pipe clamp.

(5) The specifications of hydraulic components are unreasonable, such as adjusting large caliber for small flow, resulting in low-frequency oscillation; The system pressure is at a certain level.

Part of it produces * * * vibration.

3. Efficiency; The efficiency of hydraulic system is generally low, with only 80% or less stones left. The low efficiency of the system is mainly caused by heating, oil leakage and high back pressure of oil return.

4, fever problems; Throttle speed regulation, overflow of overflow valve and high back pressure of gas oil return in the system are the main reasons for the heating of winding belt. 5. Oil leakage problem

(1) Parts (including hydraulic parts, seals and pipe joints) are of poor quality, resulting in oil leakage.

(2) Whether the sealing form is reasonable, such as one-way air seal and two-way seal.

(3) Whether the pipeline is made reasonably and whether the pipeline is full of strength.

(4) Abnormal vibration leads to loose pipe joints.

(5) The connecting screws of hydraulic components are not rigid enough, such as oil leakage from domestic superposition valves.

(6) The machining accuracy of oil circuit block and pipe joint is not enough, such as incorrect sealing groove size, unreasonable requirements for finish and form and position tolerance, and oil leakage.

6. Maintenance problems and difficulties are mainly due to:

(1) The design is not thoughtful, the maintenance space is small, and the maintenance is inconvenient.

(2) Maintenance workers are required to have a high technical level.