In order to make a hydraulic system work reliably for a long time, the following problems must be carefully paid attention to in the design or use process:

(1) Prevent air from mixing into the system and timely discharge the air mixed into the system. If air enters the hydraulic system, it will cause noise, oil oxidation and deterioration and other adverse consequences. Measures must be taken to prevent air from mixing in, and the air mixed in the system must be regularly discharged.

(2) Always keep the oil clean. The impurities mixed in the oil will cause the slide valve to be stuck, block the orifice or gap, make the hydraulic components unable to work normally, and make the relative moving parts more worn. In addition to installing oil filters and various devices to prevent external impurities from mixing into the system, oil filters shall be cleaned regularly and old oil shall be replaced. When assembling the hydraulic system, clean all hydraulic components and pipes. After commissioning, it is better to disassemble all components and pipes, clean them carefully and then install them.

(3) Prevent leakage. External leakage is not allowed, and internal leakage is inevitable, but its leakage amount cannot exceed the allowable value. If the leakage is too much, the pressure will not rise, and the hydraulic servo motor cannot reach the expected force (or torque). And the amount of oil leakage is related to the pressure, which will make the movement of working parts unstable. In addition, due to excessive leakage, the volume loss will increase and the oil temperature will rise. In order to avoid excessive leakage, appropriate clearance and sealing device should be installed between relative moving parts.

(4) Avoid excessive oil temperature. Generally, the oil temperature of hydraulic system should be kept at 15-50 ℃. Excessive oil temperature will bring a series of adverse consequences.

The increase of oil temperature will make the oil thinner, increase the leakage and reduce the system efficiency. The oil is easy to deteriorate when it works at high temperature. To avoid excessive oil temperature, in addition to taking measures to avoid oil heating in the design (such as oil pump unloading and volume speed regulation for high-power systems), it is also necessary to consider whether the oil tank has sufficient heat dissipation capacity. If necessary, a cooling device can be added.