Hydraulic oil into the air is mainly due to the hydraulic system leakage, hydraulic pump leakage and hydraulic tank fluid disorder caused by three aspects. Air enters the hydraulic system, appears in the form of bubbles in the hydraulic oil, bubbles produce a lot of heat, temperature rise, damage additives and liquid itself, accelerate cavitation corrosion of metal parts, oil aging, the oxide produced will damage the system components, resulting in the maintenance of the hydraulic system difficult to increase.

Hydraulic oil is the main source of air pollution

1. The oil absorption filter is blocked by dirt, the oil deteriorates, deteriorates and emulsifies, and the defoaming performance becomes poor;

2. Poor sealing or vibration looseness of the oil-grade suction pipe line leads to pipe cracking and air intake;

3. From the pump shaft oil seal, pump body and pump cover fitting surface, hydraulic cylinder piston rod and end cover outside air intake;

4. The return pipe is not inserted below the oil level of the oil tank or loosened, and air is poured back into the return pipe;

5. The pressure of the oil suction chamber of the pump is lower than the air separation pressure of the hydraulic oil, resulting in the precipitation of dissolved air;

6. Local pressure in the hydraulic system is lower than saturated vapor pressure, and air is separated from oil.

Ii. Main hazards of hydraulic oil air pollution

1. The compressibility of oil increases by 1000 times, resulting in movement error and crawling and vibration;

2. The rigidity of the system decreases, which greatly reduces the response of components to actions and makes the actions sluggish;

3. Bubbles are crushed by pressure oil, resulting in strong vibration and noise;

4. When the bubble is compressed, it releases a large amount of heat and burns and oxidizes locally, resulting in deterioration and deterioration of the hydraulic oil;

5. Bubbles enter the lubrication part and cut the oil film, resulting in burns, wear and friction on the sliding surface;

6. Bubble storage tank increases the volume, oil spills from the tank and pollutes the ground;

7. Bubbles lead to cavitation, which causes chemical reactions between oil and additives in oil, thus reducing the performance of oil.

Main measures to eliminate air pollution

1. Add enough oil, and the oil level of the oil tank shall always be not lower than the oil indicator line of the oil mark during the operation of the equipment;

2. The capacity of the oil filter is sufficient, and regularly remove the dirt attached to the filter mesh or filter element of the oil filter;

3. The inlet and return pipelines of the oil tank should be separated from each other as far as possible to prevent the undefoamed oil from being sucked into the pump;

4. Pay attention to the external leakage of various hydraulic components, often where the leakage is carried out;

5. Improve oil defoaming performance, add defoaming agent when necessary, which is conducive to oil defoaming and defoaming;

6. Add an exhaust device or loosen the pipe joint at the highest part of the equipment to exhaust when there is no exhaust device;

7. The suction port of the pump to the liquid level as low as possible, can absorb oil vacuum degree does not exceed the provisions;

8. Try to reduce the pressure difference between the upper and lower throttling orifice. For the parts where pressure drop is likely to make the pressure very low, the pressure should not be lower than the air sharing pressure of oil, resulting in air sharing and precipitation.