Heating of hydraulic system is not only a common fault phenomenon of excavator, but also a complex fault to analyze and deal with.
Under normal working conditions of excavator, the oil temperature of hydraulic system shall be below the specified temperature. If it exceeds more, it is called hydraulic system heating. The fault features are as follows: when the excavator works cold, all kinds of actions are normal. When the machinery works for about one hour, with the increase of hydraulic oil temperature, there will be weakness and sluggish action of each actuator of the excavator, especially insufficient excavation force and difficult walking and steering.
The heating of the hydraulic system leads to a variety of conditions of the excavator, which must be analyzed and handled carefully. If the hydraulic system generates heat and cannot be handled in time, it will have a very adverse impact on the system:
(1) The oil viscosity decreases, the leakage increases, and the system heats up, forming a vicious circle;
(2) Accelerate the oxidation of oil, form colloidal substances, block the small holes of components, so that the hydraulic components fail or get stuck and cannot work;
(3) Aging and failure of rubber seals and hoses;
(4) The wear of oil pump and hydraulic valve parts is intensified and even scrapped.
Generally speaking, such faults as heating of the hydraulic system should be analyzed from the outside to the inside of the hydraulic system.
The internal reason is mainly caused by unreasonable system design. Such as unreasonable matching between components, too thin pipeline channel, many elbows, small bending radius, insufficient oil tank volume and other factors. Such problems should be fully considered in the design stage, otherwise it will cause congenital deficiencies in the excavator hydraulic system, which will be difficult to overcome after being made into products.
When dealing with the heating fault of the hydraulic system of an excavator, it was found that the oil level in the damping box greatly exceeded the observation oil level screw, and these excessive oil generated a lot of heat and transferred to the hydraulic pump during the rotation of the damping damper, resulting in the heating of the system. At this time, the fault can be eliminated after the oil in the damping box is drained to the standard oil level. There are two reasons for the high oil level in the damping box: first, the operator refuels blindly; Second, the oil seal at the shaft end of the hydraulic pump is aging, resulting in the leakage of hydraulic oil. The latter should remove the bolt and replace the oil seal of the hydraulic pump.
