1. Noisy
①The curved surface of the stator is not smooth. Polished stator curved surface.
②With the end face and inner hole of the oil pan, the verticality error between the blade end face and the side is large. 01mm。 Repair and match the end surface of the oil pan and the side of the blade, so that the verticality error is within 0.01mm.
③The triangular groove of the oil pressure window of the oil distribution plate is too short. Repair the triangular groove to ensure communication between two adjacent blades.
④ The oil inlet is not tightly sealed and air is mixed. Check the oil inlet pipe and pipe joint and tighten.
⑤ The oil intake is not smooth, and the pump is not sucking enough oil. Remove the dirt in the filter or the oil inlet pipe, and add enough working oil.
⑥The pump works under overpressure. Must work below the rated pressure.
⑦ Vibration caused by motor or other machinery. For example, the coaxiality of the spline shaft and the prime mover shaft, and whether there is a rubber pad vibration reduction problem.
When you feel that the pump running noise is large, you should pay attention to whether there is cavitation (the frequency of the noise is high, indicating the existence of cavitation). If there is, it should be checked and eliminated from the poor air tightness of the inlet and return pipes. If abnormal noise with a frequency different from the normal noise is generated, 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, and it should be tightened or adjusted so that its coaxiality is not Greater than 0.2mm; the blades are installed reversely or the blades have different heights or the blade chamfers are too small. The direction should be corrected respectively. The height difference is less than 0-1mm. Change the chamfers to 1X45 ° or rounded corners; the blades are stuck and should be The blade is equipped first to ensure clearance.
Other causes and elimination of excavator failure:
① The phenomenon of trapped oil. The triangular groove of the oil distribution pan should be repaired.
②The surface of the stator curve is roughened. Should be ground and polished.
③The end face of the oil distribution pan is not perpendicular to the inner hole, causing uneven wear. 01mm should be repaired, so that the perpendicularity of the end face and the inner hole is 0. 01mm
④ The end face of the oil distribution pan is scratched. Should be retrained.
⑤ Caused by pump pressure and flow pulsation.
2. Insufficient oil
①The radial clearance is too large. The inner hole of the oil distribution pan or the spline shaft is seriously worn and needs to be replaced.
②The axial clearance is too large. The control gap is within 0.04 ~ 0.07mm.
③ The clearance between the blade and the blade groove is too large. Re-grind the blade gap, it is required to control the gap within 0.013-0.018mm.
④ The inner curve of the stator is worn. Grind or replace the stator on a dedicated grinding machine.
⑤ The oil intake is not smooth. Clean the filter and change the working fluid regularly.
3. Oil leakage
①The installation of sealing ring is bad or damaged. Reinstall and replace.
② Improper selection of oil seal material. The oil seal of oil resistant rubber should be selected.
③ Poor contact on each sealing surface. Check whether the various structural surfaces in the vane pump are deformed or have burrs, and trim them. For example, the axial gap between the oil distribution plate and the rotor is too large, and the value is 0.015 ~ 0.02mm.
④The back pressure of the oil seal is too high. Ensure that the back pressure of the oil seal is below the pressure resistance value.
4. Large pressure pulsation
Vane pump theoretically, pressure pulsation should be small, but in fact there is a large pressure pulsation. In most cases, it can be considered that it is caused by the vibration of the relief valve, but it is also caused by the pulsation of the pump flow. A large pressure pulsation of the pump will excite the pipeline and cause noise to the entire machine. If a noise frequency analysis is performed, there is a peak sound pressure at a frequency below 1000 Hz.
The reasons for the large pressure pulsation are: changes in the internal leakage of the pump, abnormal blades, and abnormal wear of the stator curve. The solution is disassembly repair or replacement.
