The normal working temperature range of hydraulic system should be between 30 degrees Celsius and 60 degrees Celsius. The temperature of hydraulic system is too high, which not only leads to the increase of system leakage and the deterioration of lubricating performance of oil, but also reduces the efficiency of the whole system. Accelerate the deterioration of oil quality. For excavators, there are also a number of problems:
1. The temperature of the system increases, the viscosity of the oil will decrease, the leakage will increase, the actuator of the excavator will move slowly, and the work will be weak when it is serious, which will lead to insufficient excavation force and difficulty in lifting the arm. At the same time, the increase of leakage, but also make the system heating intensified, forming a vicious circle.
2. The oil temperature rises, will accelerate the oil oxidation, the oil quality deteriorates. The results show that if the working temperature of hydraulic oil in hydraulic system exceeds 55 degrees Celsius, the service life of oil will be shortened by half for every 9 degrees Celsius increase. The colloidal substance formed by the oxidation of oil will also block the small holes in the control element, make some control elements fail or jam, and lead to the mechanical failure to work normally.
3. The excessive temperature of the hydraulic system, the rubber pipeline in the system will be aged, the sealing elements will be damaged, and the damage of the system will be accelerated.
4. The oil temperature is too high, the parts inside the hydraulic components can expand because of overheating, destroy the original normal fit gap between the relative moving parts, cause the friction resistance to increase, and even some control elements are stuck. At the same time, too high oil temperature can reduce the strength of lubricating oil film in the element, aggravate the mechanical wear, cause excessive wear and failure of hydraulic components, and reduce its service life.