Most of the causes of Vane Pumps failure may be caused by insufficient pressure or no pressure at all. Chinese vane pump manufacturer, supplier & Zhejiang Yongling Hydraulic Machine Co , Ltd. explained:
1. The oil distribution plate is in poor contact with the end surface (fixing surface) of the casing, and there is a large amount of dirt between the casings, so part of the pressure oil in the pressure chamber flows into the low-pressure area through the gap between the two, and the output flow is reduced. Remove and clean to close it.
2. The mating end (sliding surface) of the oil distribution plate and the rotor is worn, resulting in severe wear, large internal leakage, and insufficient output flow. You can use thicker (but not too thick) sandpaper to polish the high points of the fluff, then use a fine emery cloth to remove the dents and use after polishing.
3. The inner hole (inner curved surface) of the stator is worn and worn. The top circle of the blade and the curved bracket of the stator hole scratch the groove and leak to the oil suction area, resulting in insufficient output flow. The inner surface of the stator can be polished with metallographic sandpaper.
4.Blade and backdrill assembly (pump element) installed upside down
5. The pump body has casting defects such as pores, trachoma, shrinkage, etc., and is pierced. Therefore, the high-pressure cavity and the low-pressure cavity are locally connected and cannot suck oil. At this point, the vane pump can be replaced.
6. The axial clearance is too large, that is, the thickness of the rotor of the vane pump is too different from the thickness of the stator and the depth of the hole of the vane pump body. Increased leakage reduces output flow.
7. The variable mechanism is adjusted incorrectly or something goes wrong, and you can take appropriate action after determining the cause.
8. The end face of the oil distribution plate is worn or slotted, the internal leakage is large, and the output flow is insufficient. Generally, the end face of the oil distribution plate must be grounded.
9, the oil filter is clogged, or the filtration accuracy is too high, no or little oil (depending on the degree of clogging), can be removed and washed.
10. The viscosity of the hydraulic oil is too low, especially for small capacity vane pumps. When the oil viscosity is too low or the oil temperature rises too high, the oil produced by the vane pump usually cannot be loaded to the required pressure. This is because the internal viscosity of the oil is too low, and internal leakage increases due to an increase in temperature.
11. For pressure-limiting variable vane pumps, if the pressure regulating screw is improperly adjusted, the flow will significantly decrease after exceeding the pressure limit, and it will be difficult to increase the pressure after entering the system.
12. After the parts in the vane pump are worn, although the pressure can be increased at low temperature, after the equipment runs for a period of time, the oil temperature rises, the internal leakage due to wear is large, and the pressure loss is also large. (Cannot reach the highest point). If you try to adjust (tighten the safety valve) at this time, your hand will shake violently. At this point, it can be determined that the vane pump is severely worn. If a new vane pump is replaced, the pressure will rise immediately.
13. The inner surface of the stator is scratched, resulting in poor contact between the top of the blade and the inner curved surface of the stator, large internal leakage, reduced flow, and difficult pressure adjustment. At this time, the curved surface of the stator should be polished or the stator should be replaced.
14. For medium and high pressure vane pumps equipped with a pressure reducing valve, if the output pressure of the pressure reducing valve is adjusted too high, it will cause premature wear of the blade top and the stator inner surface due to excessive contact stress. Leaks in vane pumps are large, output flow is reduced, and pressure cannot be increased.
Zhejiang Yongling Hydraulic Machinery Co., Ltd. is a large-scale high-performance hydraulic vane pump manufacturer in China. Our products have won a good reputation in China for their stable and reliable quality, and applied to the torch tower of the 2010 Asian Games. Our products occupy most of the domestic market and are exported to Southeast Asia, Russia, Africa and other foreign markets. https://www.china-vanepump.com