Working principle and design key points of precision miniature gear pump

 Working principle and design key points of precision miniature gear pump

Micro gear pump is a kind of traditional external gear pump working principle, (pictured above), the liquid enters the pump suction side, is not between meshing tooth cavity suction, the outer diameter of the gear on both sides and work closely with shell, rotary motion with the teeth along the shell, the liquid between the gear to the outlet, the cycle will be no pulse continuous carrying out liquid. Gear pump is also known as positive displacement pump, has many characteristics, such as stability of flow rate, pressure is high and stable, in theory, positive displacement pump rated flow and pressure has nothing to do, but the internal leakage problem is all the inherent positive displacement pump, especially at low viscosity medium performance will be more apparent, directly affects the flow and pressure size, in order to achieve high pressure difference when meeting the need of traffic and the gear pump must overcome the internal leakage of the biggest problems, there are four ways to internal leakage (see chart). In order to maximize pump performance, it is theoretically necessary for these components to have as little clearance as possible to control internal leakage. However, simply reducing clearance is not as simple as that. In the gear pump, a certain amount of internal leakage is good for the pump, such as can be used for internal bearing lubrication, reduce the friction temperature of sliding bearing, improve the service life of the pump. The control of clearance is a contradictory process. If the clearance is large, the internal leakage will be large; if the clearance is small, the bearing lubrication and cooling will not be good. Therefore, the control of clearance needs a lot of data and experience to support.

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