1. The working oil deteriorates due to entering the dirt.
The sources of dirt (such as ash, sand, soil, etc.) entering the oil are:
(1> The outside of the system is not clean. Unclean objects are brought into the system when refueling or checking the amount of oil, or enter the system through a damaged oil seal or sealing ring.
(2> The internal cleaning is not complete. There is still a small amount of dirt residue in the fuel tank or parts.
(3> The oil container or utensils are unclean.
(4> During manufacturing, rust is generated in the pipe due to hot bending of the oil pipe.
(5> Improper oil storage, unclean or deteriorated before joining the system.
(6> The oil that has gradually deteriorated will corrode the parts. The corroded metal may become free molecules suspended in the oil.
Dirt will cause wear and corrosion of parts, especially for finished parts, they will scratch the inner wall of the rubber hose, oil seal ring and packing, and these things will cause more dirt to enter the system after damage. There is a vicious cycle of damage.
2. Overheating may cause system overheating due to one or more of the following reasons:
(1> Air or water enters the oil. When the hydraulic pump converts the oil into pressure oil, the air and water will increase the heat and cause overheating.
(2> The oil level in the container is too high, and the oil is strongly agitated, causing overheating.
(3> Poor quality oil may become thinner, suspend foreign substances, or have affinity with water, which can also cause heat generation.
(4> The rated working capacity is exceeded during operation, so heat is generated.
(5> Improper adjustment of the return valve or failure to replace damaged parts in time may sometimes generate heat.
Overheating will quickly oxidize the oil, and the oxidation will release insoluble resins, sludge and acids, etc., and these substances accumulate in the oil to cause accelerated wear and corrosion of the parts, and they adhere to the surface of the finished parts. The parts will lose their original function. The oil becomes thinner due to overheating and it will make the transmission work slower.
The result of the above overheating often reflects slow transmission action and stuck oil return valve during operation.
3. The reasons for entering air in the air oil are as follows:
(1> Improperly pour down when refueling, resulting in air bubbles mixed into the oil and brought into the pipeline.
(2> The connector is loose or the oil seal is damaged, and air is sucked in.
(3> The oil suction pipe is worn, scratched or corroded, so air enters.
In addition to causing overheating when the air enters the oil, a considerable amount of air will be dissolved in the oil under pressure. If about 10% of the compressed volume belongs to dissolved air, foam will form when the pressure drops. When the working hydraulic cylinder is decompressed and returned to the oil, the foamed oil will form a "sponge". In addition, the presence of many foams in the oil will increase the total volume and cause oil spillage in the tank or oil reservoir.
Working oil containing air will cause a sudden spasm when transmitting power, making the power transmission uneven. The resulting pressure fluctuations and stress will damage parts and components, and in serious cases will cause damage to the entire system.
Working oil containing air will also cause the risk of cavitation in the hydraulic pump, which will produce greater suction and will draw more air into the system along with other impurities.
Because of the overheating caused by the air entering the oil, the air will also bring in dust at the same time. These conditions will quickly deteriorate the oil.
It can be seen from the above that pollution, overheating and air intake are intrinsically linked, so comprehensive prevention is required to ensure that the hydraulic system works properly. To this end, a special preventive maintenance system should be established for the hydraulic system. Its primary task is to strictly check the condition of the working oil.
