Gear pumps specification are like the majority of the other types of pumps. These are pumps that come with their own hydraulic gears already installed, as their name suggests. The water contained within the pumps receives the majority of its energy for work from the force that is provided by these gears. This pump uses a hydraulic gear mechanism in order to transfer water from one location to another. That is, in a nutshell, what the pump is designed to do. You can expect a steady production rate from the system as long as its power level is maintained at the same level. This article will provide a general introduction to gear pumps. Let's talk about an overview of these pumps, including the many varieties, how they operate, the benefits and drawbacks of using them, and the applications they serve. A PD (positive displacement) rotary pump is what's known as a gear pump. This type of pump helps you transport liquid water by utilizing gears that are already integrated into the pump. This kind of pump has two or more gears, which work together to generate a vacuum force and move the fluid around inside the pump. 
Different components, such as the shaft, rotors, and housing, can be assembled to create this pump. In contrast to other types of pumps such as diaphragm pumps and peristaltic pumps, these pumps offer high pressure and are available in tiny sizes. Additionally, they deliver a steady, pulsating flow of liquid. The fact that these pumps can pump viscous liquids, in addition to their ease of use, operation, and maintenance, are the primary advantages of utilizing them. The transfer of water from one location to another can be accomplished by either rotational or gear-based motions by a gear pump. In order to generate suction at the pump intake, the liquid seal rotor extends all the way through the pump casing. It is possible for the fluid that is drawn in by the pump to be transmitted to the centrifuge via the cavities that are created by the moving gears. Although these pumps are divided into a wide variety of sorts, the most fundamental gear pump designs may be broken down into just two categories. These categories include the following:
- External Gear Pump
- Internal Gear Pump
External Gear Pump: It is possible to construct an external gear pump with two gears that are both interlocking and identical, with the identical gear being supported by separate shafts from the interlocking gear. In most cases, a motor that is driving another gear can only be used to drive one of the gears at a time. A few of the shafts may be driven by electric motors, and they may be supported by bearings on either side of the structure. This is possible in a few cases. An extended intake is created whenever the gears on the inlet side of the pump come out of the grate in the opposite direction. As the gears continue to rotate along the pump body, the fluid in the cavities feeds the gear teeth. In addition, the fluid feeds the gear teeth. Within the housing area, the fluid that has become trapped is able to make its way from the inlet side to the outlet side. When the gear teeth of the gear pump meet on the discharge surface, the amount of fluid being pumped out may decrease, and it will then be forced out of the pump. Because the gears are linked together, there is no way for any fluid to flow back through the center between them. The pump is able to both increase the suction at the intake and prevent liquid leakage from the discharge side as a result of the close tolerances that exist between the gears and the cover. 
Helical, spur, or zigzag gears can be used in the design of these pumps. The following is a list of qualities included with this pump:
- These pumps have a straightforward design and a substantial size.
- These are adequate for high-capacity distribution thanks to the enormous ports at their disposal.
- It deals with pressures such as low, medium, or high shaft support, in addition to having precise tolerances on both gear surfaces.
Internal Gear Pump: The internal gear pump operates on the same concept as the external gear pump, with the exception that the connecting gears are of different sizes, with one gear spinning inside the other. The rotor is a bigger gear that is also an internal gear. Additionally, it has projecting teeth contained within it. It is necessary to install a small external gear, the primary function of which is to be engaged by the rotor in order to ensure that the gear teeth are engaged at one end. On the pump casing, which serves as the support for the idler unit, a ring and pinion assembly can be mounted. A semi-circular spacer that is fixed in place and serves both as a seal between the intake and output ports as well as a barrier against air leakage caused by the offset mounting location of the mid-unit. 
They take a lengthy draw when they emerge from the screen on the intake side of the pump, where the gears are located. As the gears continue to spin within the pump body, fluid rushes into the cavities, where it is caught by the gear teeth and pushed farther into the pump. In the casing area, it is possible for liquid that has been trapped to be moved from the inlet side to the discharge side. When the gear teeth are attached to the discharge surface of the pump, the quantity can be decreased, and the fluid can be ejected with a greater amount of force. Spur gears are the only type that are used in the plans for internal gear pumps. The following is a list of markers that are characteristic of internal gear pumps:
- It is possible to run for a short distance.
- It leaves a massive and extensive imprint.
- The requirement for the Net Positive Suction Head (NPSH) is extremely modest.