The hydraulic gear pump is driven by an independent motor, which can effectively block the upstream pressure pulsation and flow fluctuation. The pressure pulsation at the outlet of the gear pump can be controlled within 1%.
Using a gear pump in the extrusion production line can increase the flow output speed and reduce the shearing and residence time of materials in the extruder.

How to check and eliminate common faults of hydraulic gear pumps?
1. The pump does not produce oil
① During the debugging of the hydraulic system, it is found that the gear pump does not produce oil. First, check whether the rotation direction of the gear pump is correct.
②Gear pumps can be divided into left and right rotations. If the rotation direction is wrong, the pressure oil caused by the volume difference generated by the meshing of the internal gears will cause the oil seal to be washed out and cause oil leakage.
③ Check whether the oil filter at the oil inlet end of the gear pump is blocked, which will make it difficult or impossible to absorb oil, and the oil suction hose will be sucked flat.
2. The oil seal is flushed out
①The rotation direction of the gear pump is wrong. When the rotation direction of the pump is not correct, the high-pressure oil will directly pass to the oil seal, because the general low-pressure skeleton oil seal can only accept a pressure of 0.5MPa at most, so the oil seal will be flushed out.
②The gear pump bearing bears the axial force. The occurrence of axial force is often related to the tight fit between the shaft extension end of the gear pump and the coupling sleeve, that is, the pump shaft is subjected to a backward axial force when the pump is hit with a hammer or hard pulled through the mounting screws during installation. As the pump shaft rotates, this rearward axial force will force increased wear within the pump. Because the inside of the gear pump is sealed by the fit and seal of the gear end face and the shaft sleeve end face, when the axial seal end face is severely worn, a certain gap will be formed in the axial seal inside the pump, resulting in the communication between the high and low pressure oil chambers and the oil seal rushing out .
③The gear pump bears excessive radial force. If the coaxially of the gear pump is not good during installation, the radial force on the pump will exceed the bearing limit of the oil seal, which will cause oil seal leakage. At the same time, it will also cause damage to the floating bearing inside the pump.
3. Fever
① The hydraulic system is overloaded, mainly manifested in excessive pressure or speed.
②The cleanliness of the oil is poor, the internal wear is aggravated, the volumetric power is reduced, and the oil leaks from the internal gap to save heat.
③The oil outlet pipe is too thin, and the oil flow rate is too high. Generally, the oil outlet flow rate is 3-8m/s.
4. The traffic cannot meet the specification
①The oil inlet filter element is too dirty and the oil absorption is insufficient.
②The installation height of the pump is higher than the self-priming height of the pump.
③The oil suction pipe of the gear pump is too thin, resulting in high oil suction resistance. Generally, the maximum oil absorption flow rate is 0.5.
④ Air leakage at the oil suction port joint causes insufficient oil suction of the oil pump. You can judge whether the system is leaking by observing whether there are air bubbles in the fuel tank.
5. Can't bear the pressure or can't work under the pressure
①This phenomenon is mostly related to the cleanliness of the hydraulic oil. If the oil is not selected correctly or the cleanliness of the oil in use does not meet the specification requirements, it will accelerate the internal wear of the pump and cause leakage.
② Choose mineral hydraulic oil containing additives, which can prevent oil oxidation and air bubbles.
③ After investigating the shaft sleeve and side plate of the faulty gear pump, it is found that if the cleanliness of all oils is poor, obvious groove marks will occur on the surface of the conflicting pair, while only uniform surface marks will occur on the sealing surface of the normally worn gear pump.
6. Gear pump burst
①The pressure resistance of the gear pump made of aluminum alloy is 38. On the premise that it has no manufacturing defects, the explosion of the gear pump must be caused by the instantaneous high pressure.
②The oil outlet pipeline is blocked by foreign matter, causing the pressure to rise infinitely.
③The pressure adjustment of the safety valve is too high, or the opening and closing characteristics of the safety valve are poor, and the response is lagging, so that the gear pump cannot be protected.
④ If the system uses multi-way reversing valves to control the direction, some multi-way valves may have negative openings, which will cause the gear pump to be damaged due to dead point boost.

Zhejiang Daye Auto Parts Co., Ltd. is a China hydraulic power units supplier, providing wholesale sales of hydraulic pumps, welcome to consult.