A gear pump is a type of positive displacement pump that contains two gears, the drive gear and the driven gear. The gears rotate around their respective axes and mesh with each other, creating a fluidic seal. As the gears rotate, they create a suction action which draws fluid into the pump. The fluid then passes through the meshing gears and is forced out the discharge port.
Gear pumps come in two types, external and internal. External gear pumps have their gears located external to the pump housing, while internal gear pumps have their gears located inside the pump housing. The following characteristics will focus on the external gear pump.
Characteristics of a Gear Pump
1. Positive Displacement
As mentioned earlier, gear pumps are positive displacement pumps. This means that they deliver a fixed amount of fluid for every rotation of the gears, regardless of the resistance offered by the system. This property makes gear pumps ideal for pumping viscous fluids such as oils, fuels and syrups.
2. High Efficiency
Gear pumps are one of the most efficient types of pumps. This is because of the small gap between the gears and the pump housing. As the fluid moves through this small gap, it creates pressure which helps to prevent any fluid from leaking back into the suction opening. This tight seal ensures that the fluid is efficiently delivered to the discharge port.
3. Low Flow Rate
Gear pumps are suitable for low flow rate applications. This is because they have a smaller capacity than other types of pumps. The flow rate of a gear pump is usually less than 1,000 gallons per minute.
4. High Pressure
Gear pumps are capable of generating high pressure. This is because the tight seal between the gears and the pump housing creates a high resistance to the fluid flow. The maximum pressure that a gear pump can generate is usually around 3,000 psi.
5. Self-Priming
Gear pumps are self-priming, which means that they can create a vacuum and draw fluid into the pump without the need for external assistance. This makes them ideal for use in applications where the fluid is located below the pump.
6. Low Viscosity
Gear pumps are not suitable for pumping fluids that have a low viscosity. This is because the tight seal between the gears and the pump housing can create a high resistance to the fluid flow, which can cause the pump to cavitate. As a result, gear pumps are not recommended for pumping water or other low viscosity fluids.
7. Low NPSH
Gear pumps require a low NPSH (Net Positive Suction Head). NPSH is the measure of the pressure required to prevent cavitation from occurring in a pump. Gear pumps have a low NPSH requirement because of their tight seal which helps to prevent cavitation.
8. Simple design
Gear pumps have a simple design, which makes them easy to service and maintain. They are composed of only a few components, which means that there are fewer parts that can fail. As a result, they require less maintenance and have a longer lifespan.
Conclusion
Gear pumps are an efficient and reliable type of pump that are ideal for pumping viscous fluids such as oils, fuels, and syrups. They are capable of generating high pressure and are self-priming, making them suitable for use in various applications. However, they are not recommended for pumping water or other low viscosity fluids due to their high resistance to fluid flow. Overall, gear pumps are a simple, low-maintenance solution for pumping fluids in a variety of industries.
Post time: Apr-06-2023
