1. The working oil deteriorates due to dirt.
The sources of dirt (such as ash, sand, soil, etc.) entering the oil include:
(1 > the outside of the system is not clean. Unclean objects are brought into the system when refueling or checking the oil quantity, or enter the system through damaged oil seal or sealing ring.
(2 > the internal cleaning is not complete. There is still a small amount of dirt residue in the oil tank or components.
(3) the refueling container or appliance is dirty.
(4 > rust scale is generated in the pipe due to hot bending of oil pipe during manufacturing.
(5 > the oil is stored improperly, and it is dirty or deteriorated before being added to 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, which will scratch the inner wall of rubber hose, oil seal ring and packing. After these things are damaged, more dirt will enter the system, forming a vicious circle of damage.
2. Overheating system overheating may be caused by one or more of the following reasons:
(1 > air or moisture enters the oil. When the hydraulic pump changes the oil into pressure oil, the air and moisture will contribute to the increase of heat and cause overheating.
(2 > the oil level in the container is too high, and the oil is strongly stirred, resulting in overheating.
(3) oil with poor quality may become thinner, causing foreign substances to suspend or have affinity with water, which will also cause heat generation.
(4 > when working, it exceeds the rated working capacity, resulting in heat.
(5) if the oil return valve is not adjusted properly or the damaged parts are not replaced in time, sometimes heat will be generated.
Overheating will make the oil oxidize rapidly, and the oxidation will release insoluble resin, sludge and acids. These substances accumulate in the oil, resulting in accelerated wear and corrosion of parts, and they adhere to the surface of finished parts, which will also make the parts lose their original functions. The thinning of oil due to overheating will also slow the transmission.
The result of the above overheating is often reflected in the slow transmission action and the stuck oil return valve during operation.
3. There are several reasons for entering air in air oil:
(1) pour down improperly during refueling, resulting in bubbles mixed into the oil and brought into the pipeline.
(2) the joint is loose or the oil seal is damaged, and the air is sucked in.
(3) the oil suction pipeline is worn through, scratched or corroded, so air enters.
In addition to overheating caused by air entering the oil, a considerable amount of air will be dissolved in the oil under pressure. If the compressed volume is about 10% of the dissolved air, it will form foam when the pressure drops. When the working hydraulic cylinder is decompressed, the foam oil will form the sponge character. In addition, many bubbles in the oil will increase the total volume, causing oil spills or oil spills.
The working oil containing air will produce jerk spasm when transmitting power, resulting in uneven power transmission. The resulting pressure fluctuation and stress will damage the parts and, in serious cases, the whole system.
The working oil containing air will also cause the risk of cavitation of the hydraulic pump, resulting in greater suction, which will suck more air and other impurities into the system.
Overheating is caused by air entering the oil, and dust will be brought into the air at the same time. These conditions will make the oil deteriorate quickly.
It can be seen from the above that pollution, overheating and entering the air are intrinsically related. Therefore, comprehensive prevention should be carried out to ensure the normal operation of the hydraulic system. Therefore, it is necessary to establish a special preventive maintenance system for the hydraulic system, and its primary task is to strictly check the condition of working oil.
