1. High noise
1. The surface of stator curve is not smooth. Polishing the surface of stator curve.
(2) Verticality error between end face and inner hole of oil distribution pan, and between end face and side face of blade is large. Repair end face of oil distribution pan and side face of blade so that the verticality error is 0.Within 01mm.
(3) The triangular groove of the oil pressure window of the oil distribution pan is too short. Repair the triangular groove to ensure the communication between the adjacent two blades.
4. The oil inlet is not tightly sealed and mixed with air. Check the oil inlet pipe and pipe connector and tighten them.
_Poor oil intake and insufficient oil suction by pump. Remove dirt from filter or oil intake pipe and add enough working fluid.
_Pump operates under overpressure. Must work below rated pressure.
_Vibration caused by electric motor or other machinery, such as coaxiality between spline shaft and motor shaft, vibration reduction by rubber pad, etc.
When the noise of pump operation is large, attention should be paid to the existence of cavitation (the high frequency of noise indicates the existence of cavitation).If any, check and eliminate the poor air tightness of inlet and return pipes. If abnormal noise with different frequencies from normal noise occurs, it may be considered to be related to the rotating parts of the pump. The failure may be: the coupling is loose or not concentric with the main shaft, it should be tightened or adjusted so that its coaxiality is not more than 0.2mm; inversion or different height of blades or chamfering of blades in the bladesToo small, should correct the direction separately, the height difference is less than 0-1mm, the chamfer should be changed to 1X45 degree or round corner; if the blade is stuck, it should be equipped with blades first to ensure the clearance.
Causes and troubleshooting of other faults of Kobelco excavator:
(1) Oil trapping. The triangular groove of the distribution pan should be repaired.
2. Surface of stator curve is burred. It should be ground and polished.
(3) The end face of the oil distribution pan is not perpendicular to the inner hole, resulting in eccentric wear. The oil distribution pan should be ground so that the perpendicularity between the end face and the inner hole is 0.01mm
4. The face of the oil distribution pan is scratched. It should be re-studied.
_Caused by the pressure and flow fluctuation of the pump.
2. Insufficient oil
(1) Excessive radial clearance. The inner bore or spline shaft of the oil distribution pan is worn seriously and needs to be replaced.
(2) The axial clearance is too large. The control clearance is within 0.04~0.07 mm.
(3) The mating clearance between blade and blade groove is too large. To reapply the blade clearance, it is required to control the clearance between 0.013 and 0.Within 018mm.
4. Curve wear in stator. Grind or replace stator on special grinder.
_Poor oil intake. Clean the filter and change the working fluid regularly.
3. Oil leakage
(1) Installation of sealing ring is poor or damaged. Reinstall and replace.
2. Improper selection of oil seal materials. Oil seal with oil-resistant rubber should be selected.
(3) Poor contact between the sealing surfaces. Check for deformation or burrs on the structural surfaces in the camber vane pump and correct them. For example, the axial clearance between the oil distribution pan and the rotor is too large, the value is 0.015 0.02mm.
4. The back pressure of oil seal is too high. It should be ensured that the back pressure of oil seal is below the pressure withstand value.
4. High pressure fluctuation
"In theory, a vane pump should have a small pressure pulsation, but in practice there is a large pressure pulsation. In most cases, it can be considered that the vibration of the relief valve is caused, but it is also caused by the flow pulsation of the pump. A large pressure pulsation of the pump will excite the pipeline and cause overall noise of the machine. If noise frequency analysis is carried out, there is a noise below 1000Hz."Frequency peak sound pressure.
The causes of pressure fluctuation are: change of internal leakage of pump, abnormal vanes, abnormal wear of stator curve. The solution is disassembly, repair or replacement.
