Rotary gear pumps are designed on the concept of positive displacement, a feature that makes them suitable for handling various types of fluids such as low viscous solvents to highly viscous substances like oils and syrups. They consist essentially of two gears which are meshed together in a casing and this is why they are well known for being simple, reliable and provide an uninterrupted flow.
This is how it works: a rotary gear pump
- Inlet Phase: The first stage begins with gears being disengaged from each other at the inlet side to create a vacuum. This vacuum causes low pressure zone allowing atmospheric pressure to force fluid into expanding cavities formed between teeth of the gear and the casing.
- Transport Phase: During their continuous revolution, fluids get trapped when they fill these cavities made by teeth. The fluid so carried out remains same in its volume capacity during movement from one end (inlet) to the other end (outlet). There is limited sliding back or forward motion ensuring that pumping processes run more efficiently.
- Discharge Phase: When the gears interlock again, due to decrease in volumes of these cavities, this compresses fluid pushing it through discharge piping under pressure. This process yields pumping action hence maintaining constant rate of flow. Reciprocation of rotating gears’ nature allows escape of fluid after every rotation thereby providing uniform supply.
- Pressure Maintenance: Precise gaps amid gears as well as with casing plus geared interaction on outlet assist in sustaining stable pump’s values. These render rotary gear pumps useful in applications requiring continuous liquid delivery under regulated pressures.
One main advantage of rotary gear pumps is that they can prime themselves without any external help. By creating vacuum at this point, it implies that fluids will be pulled without having someone manually direct them towards machine system. In several cases where there are frequent starts and stops involved, this technology becomes very effective.
Nevertheless, it should be noted that viscosity levels in a liquid, gear clearance factors and rate of revolution can affect a rotary gear pump’s efficiency. In this case, it is necessary to understand that wear and tear on gear teeth or casing results into its poor performance over time.
To sum up, rotary gear pumps are flexible, dependable and effective devices for the transfer of fluids. They work on positive displacement principle thus incorporating twin intermeshed gears rotating within a housing which intakes fluid, moves it and finally releases it under pressure; hence they can be used in many fields.
