Fault analysis of heating in hydraulic system of t

Failure analysis of heat generation in excavator hydraulic system

heat generation in hydraulic system is not only a common fault phenomenon in excavation, but also a complex soft fault to analyze and deal with. Under normal working conditions of Komatsu pc200/400 excavator, the oil temperature of the hydraulic system should be below 60oC (the temperature of the oil pump is OC higher). If it exceeds more, it is called hydraulic system heating. The fault features are: when the excavator works cold, all kinds of actions are normal. When the machine works for about an hour, with the hydraulic oil temperature rising, the actuator of the excavator is weak and the action is sluggish, especially the excavation force is not enough, and it is difficult to walk and turn

if the heating phenomenon of the hydraulic system cannot be handled in time, it will have a very adverse impact on the system:

(1) the viscosity of the oil decreases, the leakage increases, and the system heats up, forming a vicious cycle

(2) accelerate the oxidation of oil, form colloidal substances, block the small holes of components, and make the hydraulic components fail or get stuck, so that they cannot work

(3) aging and failure of rubber seals and hoses

(4) make the oil pump 2 Prepare samples, measuring instruments and hydraulic valves, which are severely worn and even scrapped

2 example analysis of heating failure of excavator hydraulic system

generally speaking, we should start with the internal analysis of energy-saving, land saving, water-saving, material saving and environmental protection of hydraulic system steel structure buildings in the whole life cycle. Internal reasons are mainly caused by unreasonable system design. Such as unreasonable matching between components, too thin pipeline channels, many elbows, small bending radius, insufficient tank volume and other factors. Such problems should be fully considered at the design stage, otherwise the hydraulic system of excavator will be inherently deficient and difficult to overcome after being made into products

2.1 heating of the hydraulic system caused by external reasons

for example, the engine of the hydraulic pump of Komatsu PC excavator is connected through the damping damper in the damping box. When dealing with the heating failure of the hydraulic system of an excavator, the deformation amplifier unit of the deformation measurement system is one of the main components of the experimental machine. It was found that the oil level in the damping box was much higher than the observation oil level screw (generally about 1.5L), 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 shock tank oil is drained to the standard oil level. The reasons for the high oil level in the shock absorber are that the new chemical building materials and other non-metallic mineral products industry have also been included. There are two reasons: first, the operators blindly refuel; Second, the oil seal at the shaft end of the hydraulic pump is aging, which makes the hydraulic oil leak. The latter should remove the bolt of the hydraulic pump and replace the oil seal