Inevitable defects of common gear pumps

Be limited to;

Large flow pulsation leads to large pressure pulsation and high noise in the system.

Internal meshing gear oil pump has the advantages of compact structure, small size and light weight.

Because the gear rotates in the same direction, the relative sliding speed is small, the wear is slight, the service life is long, the flow pulsation is far smaller than the external gear pump, so the pressure pulsation and noise are relatively small;

Allowing the use of higher speed, higher volume efficiency can be obtained.

The disadvantage of internal gear pump is also the existence of radial fluid pressure imbalance, which limits the further improvement of its working pressure;

In addition, the displacement of the gear pump is not adjustable, which limits the scope of its use to a certain extent.

At present, the research on gear pump at home and abroad mainly focuses on the following aspects:

(1) Optimal design of gear parameters and pump body structure;

(2) Radial clearance compensation and computer aided analysis of oil film between teeth;

(3) Trapped oil shock and unloading measures (including the meshing overlap coefficient between trapped oil shock and gear)

And whether unloading is complete, etc.);

(4) gear pump noise control technology;

(5) methods to reduce the flow pulsation of the west wheel pump (including reasonable selection of gear parameters and split gear, etc.);

(6) tooth surface coating technology and its characteristics;

(7) wheel 歯 bending stress and contact fatigue strength calculation;

(8) Study on variable method of gear pump;

(9) the life of the gear pump and its influencing factors;

(L0) hydraulic pressure analysis of gear pump and its high-pressure approach.

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Improving the working pressure of gear pump is a development direction of gear pump.

But increasing the working pressure will bring new problems: (D bearing life is greatly shortened;

② Pump leakage intensifies and volumetric efficiency decreases.

The root cause of these two problems is the unbalanced radial fluid pressure on the gear, and the higher the working pressure, the greater the radial fluid pressure.

At present, scholars at home and abroad for the above two problems of research is: (1) gear pump radial clearance compensation;

(2) reduce the radial fluid pressure of the gear pump, such as optimizing the gear parameters and reducing the size of the discharge port;

③ improve the bearing capacity of bearings, such as the use of composite sliding bearings instead of needle bearings.

But none of these measures has fundamentally solved the problem.