A alarm of a motor oil failure appears on an excavator dial of the job. It is used through the oil level, viscosity, and disassemble the oil filter inspection filter. How to make further details when there is no suitable testing tool Check? Excavator engines What factors in work engineering can cause an oil pressure abnormal? Excavator maintenance master is analyzed in detail against these issues.
The lubrication system of the diesel engine is mainly made of oil sump, oil pump, oil filter, radiator, main oil passage, oil traveler, oil pressure is too low alarm sensor, oil temperature over high alarm sensor, restriction valve and bypass Valve composition. The oil pressure is too low, with the following reasons:
1. Insufficient oil oil
If the oil amount of the oil fuel will reduce the amount of pump oil in the oil pump or the pump is not in the oil, the oil pressure is lowered, the crankshaft and the bearing, the cylinder sleeve and the piston will exacerbate wear due to poor lubrication. Therefore, the oil level in the oil undercar should be checked before working every day, ensuring the normal oil level, and should add the same model of the same model produced by the same manufacturer.
2, the oil pump does not turn
If the driver gear of the oil pump is damaged or falling off; the filter is damaged to inhale the foreign matter, the gear is killed, and the oil pump is stopped, the oil pressure is reduced to zero. The damaged flat or a filter should be replaced.
3, oil pump wear
The gap between the oil pump pump and the bushing, the gap between the gear end surface and the pumping cover, the tooth gap or the radial clearance, which will cause the pump oil to reduce the amount of pump oil, so that the oil pressure is lowered. At this time, the wear part should be replaced, the ground plane of the pump cover is grinded to restore the gap between the end surface of the gear to the standard range.
4, the engine temperature is too high
If the excavator engine cooling is too much, the heat dissipation is poor, long-term overload operation or the oil supply time of the injecting pump will cause the engine overheat, accelerate the aging, deterioration, and change of oil, and leak from each matching gap. Pressure decreases. Scales should be removed, adjust the oil supply time, so that the engine works within the rated load.
4. Addition gap between the main bearing and the link bearing
The mating gap between the main crankshaft and the connecting rod bearing gradually increases, and the oil pressure is reduced by the long-term use of the excavator engine. This mating gap is 0.01mm per increase, and the pressure drops 0.01 MPa. At this time, the crankshaft can be found, and the new link bearing and the main bearing are selected, and the gap is restored.
5, bypass valve damage
In order to maintain the normal oil pressure of the main oil passage, it is equipped with the mating surface of the steel ball to be worn or smashed if its regulating spring is softened or not adjusted. The pressure of the oil passage will fall. At this point, the bypass valve should be removed and finally adjusted the pressure to the normal range.
6, oil radiator oil leakage
Foreign-draft will pollute the surface of the engine, the pressure drops; the internal leakage makes the oil into the water tank, the heat dissipation effect of the cooling system is deteriorated, the excavator engine is overheating, the oil is thin, and the pressure is reduced. Remove the heat sink, repair or replace, restore its function. (Engine Protection)
7, pressure sensor failure or oil passage
If the pressure sensor fails or the oil passage of the main oil passage to the pressure sensor, the oil pressure will fall when the oil flow is not smooth. You can check the following: engine idle operation, loosen the tubing joint, observe oil flow
8, the restriction valve set pressure is too low
In the lubrication system, the oil pump pumped oil must ensure appropriate pressure before reaching the engine lubrication components. If the pressure valve sets the pressure is too low, the pressure regulating spring is soft or the sealing surface leaks, which will cause the set pressure too low. At this point, the restriction valve should be adjusted to restore the pressure normally.
9, the oil volume is not suitable
Different excavator engines need to add different grades of oil, the same model of the engine should also use different grades of oil in different seasons. If the oil is not suitable or inferior oil, the engine is operated, and the split is too low, and the pressure is lowered. It should be correct, reasonable, adapt to different models or seasons.
10, oil filter plugging
When the oil filter is blocked without flow, the bypass valve provided on its base is opened, the oil is not filtered directly into the main oil passage. If the opening pressure of the bypass valve is set too high, when the oil filter is blocked, it cannot be opened in time. The pressure of the oil pump will rise, and the inner leak will increase, and the oil supply volume of the main oil is reduced. The pressure will fall. The cleaning of the oil filter should be guaranteed; correctly adjust the opening pressure of the bypass valve, replace or repair damaged components or mating surfaces, and restore its normal operating performance.
11, the filter is blocked
(Engine Protector) Under normal circumstances, oil pressure should be higher than small throttles during large throttle, but sometimes abnormally. If the oil is too dirty, it is easy to block the filter. When the engine small accelerator is running low speed, the oil pressure can still be established to establish a certain pressure due to the oil pump, so that the oil pressure is normal; but when the accelerator is high-speed, the oil pump's oil absorbing amount will be due to the filter The resistance is too large, which is significantly reduced, so that the main oil supply oil supply is not enough to decrease. The suction filter should be cleaned, or the oil is replaced.
Through the above analysis, we took the oil pressure gauge and oil analyzer to the construction site, and the quality of the oil analyzer was used to detect the quality of the oil, and found the viscosity of the oil, and the extent of pollution was in line with the requirements. Connect the oil pressure gauge, measure oil pressure at low speed and high speed, found that the oil pressure is below 0.15 MPa, and the oil pressure is 0.15MPa when the oil pressure is low, and the high speed is 0.6MPa, so that the oil pressure is low, Normal pressure cannot be reached. In accordance with the principle of simultaneously, from the principle of the outside, we inspect the bypass valve on the oil filter holder, it is found that the steel ball and the valve seat fitting surface are sealed, resulting in the leakage of the oil, and the pressure is lowered. By grinding the sealing surface, the sealing performance is restored, the adjustment pressure reaches the standard value, the oil pressure alarm lamp is off, and the mechanical recovery is normal, the fault is released.
By excluding this fault, it means that the mechanical failure is not terrible. Just understand the system working principle, carefully analyze, it will be able to rule out the fault, but do not blindly disassemble, otherwise, it will happen half a single, or even damage the normal component.
