The fault phenomena of abnormal noise in the excavator include abnormal noise in the excavator engine, abnormal rotation noise, and abnormal rotation noise. So what are the causes of abnormal noise in the excavator?
Abnormal noise during excavator operation:
1. The excavator makes a squeaking noise during assembly work.
2. When the excavator is operating, the engine makes abnormal noise. (Excavator engine abnormal noise)
3. When the excavator rotation stops, the excavator rotation motor makes abnormal noise. (Excavator rotation abnormal noise)
4. The excavator makes abnormal noise when rotating left and right. (Excavator rotation and abnormal noise)
Reasons for abnormal noise during excavator operation:
1. Operating equipment: It is determined that the abnormal noise comes from the pin shaft at the root of the boom. The pin shaft is unevenly lubricated, causing abnormal noise during the operation of the excavator.
2. There is a gap between the crank connecting rod mechanism and the valve mechanism, causing abnormal noise in the excavator operation. Improper adjustment or failure of the engine supply system causes abnormal noise in the excavator engine.
3. There is a problem with the swing motor: the oil return back pressure valve is welded and stuck.
4. The oil supply time lags behind, resulting in abnormal noise during operation of the excavator, and blockage of the air filter element and air inlet hose.
5. Fuel injector failure causes abnormal noise during operation of the excavator.
Troubleshooting of abnormal noise during excavator operation:
1. Add butter and drain it out of the shaft sleeve.
2. The gap between the piston and the cylinder liner is too large, and there is a knocking sound in the cylinder, which is especially obvious when the speed changes suddenly or when the load is low and the sound becomes weaker when the temperature rises. Disassemble the cylinder block and piston connecting rod group, check the degree of wear of both, and replace the piston, piston ring or cylinder liner. The gap between the piston pin and the connecting rod bushing is too large, and a crisp impact sound is emitted from the upper part of the cylinder, especially when the speed changes from low speed to high speed. Replace the piston pin or bushing according to the fitting clearance specified in the assembly technical requirements. The gap between the crankshaft main journal and the bearing bush is too large, and a dull impact sound can be heard at the main bearing. As the load increases, the sound increases and the vibration also increases. Disassemble the cylinder block, inspect the main bearing bush and crankshaft, and replace the main bearing bush if necessary. The gap between the crankshaft connecting rod journal and the bearing bush is too large. Determine the cylinder where the sound occurs, check the tightening of the connecting rod cover, or replace the connecting rod bearing bush. If necessary, grind the crankshaft to eliminate abnormal noise during operation of the excavator. The crankshaft thrust plate is excessively worn and the crankshaft shafts are wandering. Replace the thrust piece promptly. The valve clearance is large. Adjust the valve clearance to the specified range according to the assembly technical requirements. The fuel supply advance angle is too small, the exhaust pipe blasts, and a low knocking sound is emitted from the cylinder. Adjust the fuel supply advance angle according to regulations. If the fuel supply advance angle is too large, the engine will work roughly, vibrate greatly, and the cylinder will make a crisp knocking sound rhythmically. Adjust the oil supply advance angle according to regulations to eliminate abnormal noise problems when the excavator is working.
3. After replacing the rotary motor, it was found that the fault still existed. After troubleshooting the rotary motor fault, we continued the inspection and found that the oil return back pressure valve was stuck by welding and could not be closed. Replace the oil return back pressure assembly with a new one to eliminate the abnormal noise problem of the excavator.
4. Observe that the engine smoke is good, there is no black smoke or blue and white smoke, and the starting performance is basically normal. However, the engine power feels reduced when the excavator is working. When the engine is accelerated rapidly, there is a severe knocking sound at the joint between the upper part of the cylinder block and the cylinder head. The knocking sound in the cylinder break test disappears inconspicuously. Check that the air filter element and air intake hose are not blocked or compressed. Check that the valve clearance of each cylinder is normal. Remove the injector and check it on the test bench. The spray condition is good. No metal impurities were found in the oil in the oil pan, ruling out wear or abnormal damage to the mechanical parts. When checking the fuel injection pump, a problem was found. The fuel supply time lags seriously. Adjust the fuel supply time to eliminate the abnormal noise problem of the excavator.
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Post time: Feb-08-2024