This article mainly expounds that the three aspects are as follows:
1 domestic, imported excavator hydraulic oil overheating fault hazards
2 domestic and imported excavator hydraulic oil overheating failure causes
3 how to prevent domestic and imported excavator hydraulic oil overheating failure?
The details of the three aspects are as follows:
1 domestic and imported excavator hydraulic oil overheating hazards:
The overheating of the hydraulic oil of the imported excavator will reduce the thermal stability and chemical stability of the hydraulic oil. The viscosity of the oil will decrease and increase the leakage, resulting in the aggravation of the wear and tear of the hydraulic pump, cylinder, valve and other components, which may cause the failure of the valve operation.
2 domestic and imported excavator hydraulic oil overheating failure causes:
The design is unreasonable
The influence of external heat source such as engine
Selection of viscosity of low quality hydraulic oil or oil
Deficiency of oil
(5) relief valve is too low in adjusting pressure or frequent in spool action.
Heat sink of cooler
Cooling fan speed reduction, etc.
3 how to prevent domestic and imported excavator hydraulic oil overheating failure:
(1) improved design and meticulous manufacture.
Second, find external heat source and eliminate or isolate. If the fuel quantity exceeds the oil line, the excavator will produce a lot of heat and transfer to the hydraulic pump during the steering of damping damper, which leads to the heating of the system, and the fluid of the damper box should be discharged to the standard oil level.
3. Hydraulic oil shall be selected according to the hydraulic oil designation specified in the product manual of the excavator's pump and valve components.
(4) perfecting the inspection system of the technical condition of the hydraulic system of the excavator and conscientiously carrying out the daily inspection and maintenance. For example, if there are no leakage in the connection places, the oil quantity in the tank is sufficient, the working temperature of the pump is normal, and the oil filter is blocked, it can effectively prevent the high temperature of the hydraulic oil.
Check the overflow valve to adjust the pressure, spring, valve core and seat. According to the opening and closing characteristics of the overflow valve, the adjustment pressure should be greater than the rating pressure 10%. of the system, and then observe whether the spring is bent, broken, and should be replaced when necessary; check whether the main valve core and the pilot valve are completely unobstructed, and to clean the damped holes in time to prevent the time blocking and blocking. Check the main valve core, if not flexible, the valve core should be repaired and reassembled. If the main valve core is not flexible, the hydraulic oil should be replaced, and the contact between the pilot valve core and the seat is good, and the roundness error of the sealing surface of the two is within 5 ~ 10um.
(6) check and dismantle the snake tube and the multi tube cooler. After cleaning the oil with sodium hydroxide and sodium carbonate, rinse with warm water, then soak and clean 40min in the dilute sulfuric acid solution of 20%~30%, the water temperature is 40~60 C, then the water is cleaned with warm water, and the coolers should be knocked lightly during the cleaning process, and the oxide peel will fall off; finally, the 10% hydrogen oxidation is made. Soak and clean 15min in the sodium solution, the solution temperature is 40~60 C, then washed with steam or warm water, and after drying in the clean and dry air, it is coated with antirust oil. Because the cooler modeling is relatively complex, if the heat sink is too much dirt to clear, it should be replaced.
Check the tape of the cooling fan and adjust it according to the regulation.
