On 4WD off-road forklift, hydraulic oil not only plays an important role in transmitting power, but also plays other important roles such as lubrication, and the temperature of hydraulic oil directly affects the working performance of loader. Now let's understand the reason why the hydraulic oil temperature of the 4WD off-road forklift is too high. I hope it can help you!
Why is the hydraulic oil temperature too high for 4WD rough terrain forklift?
Improper pressure adjustment
When the system pressure is adjusted too high, the overflow valve cannot overflow and depressurize normally, resulting in increased internal leakage and increased system oil temperature.
For the hydraulic system with back pressure valve on the oil return circuit, if the pressure regulation of the back pressure valve is too high, the oil temperature will also be too high due to excessive oil return resistance. When the oil return filter element is blocked or the oil return pipeline is aged and delaminated, it will also cause high back pressure, increase the pressure loss during oil flow, and cause too high oil temperature.
The hydraulic pump sucks air
The air suction of the hydraulic pump makes the oil mixed with too much air, resulting in cavitation and hydraulic shock under the action of high pressure, accompanied by strong vibration and noise, resulting in the rapid rise of the system oil temperature.
Most of the reasons for the empty suction of the hydraulic pump are due to the blockage of the oil inlet filter element or oil inlet pipe. If the oil pipe connection is loose or the oil seal of the transmission shaft of the pilot pump and the main hydraulic pump is damaged, the hydraulic pump will also be empty.
Poor heat dissipation
Excessive dirt deposition on the surface of the radiator will cause poor heat dissipation and ventilation, resulting in excessive oil temperature; If the liquid level in the hydraulic oil tank is too low and the oil circulating in the system is insufficient, the system oil temperature will also be too high.
Component wear
The serious wear of components in the hydraulic system can cause the system oil temperature to be too high. Many parts of components in the system are sealed by clearance. Once these hydraulic components are worn, internal leakage will increase, resulting in oil temperature rise and oil leakage The viscosity decreases, which leads to further increase of internal leakage and further increase of oil temperature, forming a vicious circle.
Friction caused by too tight hydraulic components will also lead to the rise of oil temperature.
improper selection of hydraulic oil grade
Improper selection of hydraulic oil grade, especially oil viscosity index, will directly threaten the normal operation of hydraulic system. Therefore, only hydraulic oil with specific viscosity range and small viscosity change can be selected.
When selecting hydraulic oil, the specific construction area and season should also be considered. The hydraulic oil with low viscosity should be selected for winter construction in northern China; In summer, hydraulic oil with high viscosity should be selected; For machines with clearly specified oil standards, hydraulic oil shall be filled in strict accordance with the regulations.
Internal leakage
In the process of energy transmission, if the internal leakage is serious, the volume loss of the system will be increased, and the lost energy will be converted into heat energy, resulting in excessive oil temperature of the system. If the element gap is too small, friction will occur between relative moving parts, which can also increase the oil temperature; If the clearance is too large, the leakage is serious.
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