Rotary pumps have applications in various equipment, such as hydraulic systems, laboratory equipment and automotive mechanisms. Before searching for a rotary pump that fits your application requirements, you need to be conversant with certain technical terms. Pump manufacturers use various key terms to describe types of rotary pumps and to specify the properties of rotary pumps. This guide will give you an idea about certain popular rotary pump terms, such as rotary gear pumps, rotary vane pumps, rotary lobe pumps and viscosity.
Positive-displacement pumpsIn a positive-displacement pump, a fixed amount of fluid is trapped inside the pump body and this trapped fluid is forced out through the discharge pipe. A rotary pump is the most common type of positive-displacement pump.
Rensselaer Polytechnic Institute provides information about the positive-displacement pump and its different types. You can also read through the description of positive displacement pumps at International Vacuum, an online magazine.
Rotary gear pumpsAs the name indicates, rotary gear pumps are comprised of gears to force the fluid. Rotary gear pumps are suitable for high-pressure and high-volume applications.
Alfa Pumps & Systems, a gear pump manufacturer, provides the basics of gear pumps, including their construction, principle of operation and typical applications.
Internal gear pumpsThese are positive-displacement pumps with an internal gear that is driven by the input shaft. The internal gear drives an external gear that rotates around its center. These gear pumps are suitable for pumping fluids that have low viscosity.
To understand the construction and working of an internal gear pump, you can read through an informative article at Hydraulic Equipment Manufacturers.
External gear pumpsExternal gear pumps use two identical gears rotating against each other, out of which the pinion is driven by the prime mover and the other gear rotates with it. External gear pumps are useful for applications such as fuel systems and chemical industry equipment.
Pump School provides information about external gear pumps.
Rotary vane pumpsUnlike rotary gear pumps, rotary vane pumps use vanes in the form of blades, buckets, rollers or slippers. These provide high-pressure applications.
Cole-Parmer provides information about rotary vane pumps.
Rotary lobe pumpsThese rotary pumps are comprised of rotor lobes and are suitable for low-shear applications.
Hydraulic Institute provides a definition of rotary lobe pumps. You can also read through the basics of rotary lobe pumps at Viking Pump.
ViscosityViscosity of the fluid is an important parameter for the design and performance of a rotary pump. Viscosity indicates the resistance of the fluid to flow. The more viscous the liquid, the lower its flowing rate.
To understand the meaning of viscosity and its units, read through information at STLE. Additionally, Eaton Corporation offers a hydraulics glossary that explains viscosity.