Four Reasons to Invest in External Gear Pumps

Hydraulic Piston Pumps Versus Hydraulic Gear Pumps | Panagon Systems

Gear pumps are routinely used in high-pressure applications. They are engineered with reinforced components and specialized seals to withstand the extreme forces of boosting fluid pressure. The drive mechanism gives rotary motion to the rotor gear, which causes the idler gear to rotate. The tight clearances between the gear teeth and the stationary crescent seal minimize fluid from internally leaking backward.

High Efficiency

Liquiflo gear pumps have a high-efficiency level and transfer fluids with minimum energy loss. They can operate at higher speeds and deliver high-pressure capabilities, making them ideal for hydraulic systems. When a gear pump is running, the two rotating gears unmesh at the suction side of the pump. This creates a vacuum and draws fluid from the surrounding area into the pump. Once the fluid enters the gear teeth, it is imprisoned and can only migrate to the discharge side of the pump, where it is pushed out under force. The running clearances between the gear faces, gear tooth crests, and housing cause a slight loss to the pumped volume, known as flow slip. This is nearly constant at different speeds and flows and changes linearly with pressure. Therefore, gear pumps must be run close to their maximum rated speed to achieve high volumetric efficiency. They also require lubrication to ensure the gears do not rub together, causing damage.

Low Maintenance

Gear pumps require less maintenance than other pump types. They only have a few moving parts, which reduces the likelihood of mechanical failure. The operation of a gear pump depends on tight clearances between the gear teeth and the chamber. If the seals or bearings are worn, it can cause leakage. Inspecting the shaft seals and replacing them when necessary is essential to prevent fluid loss. The teeth of the gears mesh together, creating a series of cavities between them (inlet stages). These cavities trap liquid inside and transport it towards the outlet port. Gear pumps aren’t recommended for use with fluids containing suspended solids because the abrasive particles can damage the pump’s internals. They are also unsuitable for applications that need long periods of dry operation. They can suffer from increased wear and noise, so it’s best to use alternative pumps for these applications.


Gear pumps have fewer moving parts than other positive-displacement pump types, leading to a lower failure rate. Nevertheless, other factors contribute to reliability. For example, a gear pump cannot handle fluids containing suspended solid particles. This can cause clogging and damage to the internal components. Additionally, a gear pump must be adequately lubricated with the manufacturer-recommended product to prevent excessive friction that can cause overheating and reduced efficiency. Gear pumps also rely on tight clearances between their moving parts. Therefore, inspecting these areas regularly for signs of wear and tear is essential. This is especially true for shaft bearings, which can be inspected by inserting a piece of paper between the gear teeth and casing. This test will help you determine whether the bearings are worn down and must be replaced. A well-maintained gear pump will operate with high precision for a long time.


Gear pumps can be engineered in many different sizes and designs to accommodate a variety of applications. They can handle low to medium temperatures, high pressures, and viscosities, making them ideal for several industrial processes, including metering and transporting chemical additives, fuels, polymers, and more. They are also often used in automotive systems to power the lubrication system, fuel injection, and hydraulic power steering. Additionally, they are well suited for use in food and pharmaceuticals due to their hygienic design and ability to handle viscous products. With close tolerances and shaft support on both sides, external gear pumps are designed to handle a wide range of liquids. They can withstand high levels of friction between the gears. However, it is essential to be aware that this type of pump is not well suited to handling abrasive or extremely high-temperature fluids, as these liquids can cause excessive wear on the gear teeth and lead to slippage.