What is the high temperature of hydraulic oil of loader? What are the causes of heat in hydraulic system?

The heating of the hydraulic system of the loader will cause some faults, such as inflexible operation, automatic lowering of the boom, difficulty in lifting and overturning the bucket, and reduced working pressure.

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1, cause analysis

(1) High working environment temperature.

Continuous operation in hot summer, coupled with poor cooling effect or poor heat dissipation, causes the machine to generate more heat than heat dissipation, making the oil temperature too high.

(2) Overloaded work for a long time

The loader works under high pressure and high power for a long time, the overflow valve is frequently opened, and the oil circuit and components in the hydraulic system are heated due to long-term high pressure unloading.

(3) the hydraulic pump generates heat

Hydraulic pump is the main element to generate heat. High rotating speed of hydraulic pump, high oil discharge pressure, bad working environment, oil pollution, irregular oil selection or too little oil will all cause pump loss and leakage. Leakage in the pump will increase its power loss and lead to serious wear. Oil invades the air and is easily compressed, which may cause dry grinding of the pump. Long-term leakage, dry grinding or severe compression of the hydraulic pump will inevitably generate heat, which will heat up the oil and the system.

2. Fault examples

There used to be a loader, and the shovel was weak and the operation was invalid. Touching the high-pressure oil pipe by hand feels very hot, which is initially determined to be caused by the heat of the hydraulic system. The hydraulic pump was inspected and it was found that the pump casing was very hot and noisy. When checking the hydraulic oil, it was found that the oil had deteriorated. The analysis shows that the hydraulic pump is likely to get hot due to oil pollution, so the hydraulic oil is replaced. When replacing, clean the oil pipe, oil tank and filter first; Inject a certain amount of oil into the system and discharge the cleaned oil after several cycles; Finally, add new hydraulic oil. After such treatment, the phenomenon of fever has not been eradicated, and then considering that the hydraulic pump may be worn and leaked due to oil pollution, the hydraulic pump was replaced (after the disintegration of the original hydraulic pump, it was found that the wear was serious and the fit gap was large). The test shows that the temperature of the hydraulic system has returned to normal.