5 Types of Gear Pumps: Features and Applications

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5 Types of Gear Pumps: Features and Applications

Every gear pump comes with its advantages and disadvantages, making specific pumps ideal for certain circumstances. Knowing the five types of gear pumps their features and their applications will allow you to decide what you need to install and how it will benefit you. Ensure that your pump can handle the particulates present in your liquid and the viscosity—settling for something less-than-ideal will result in greater expenses and repair costs. Let’s learn about 5 Types of Gear Pumps.

External Gear

With external gears, you’ll typically find that two spur gears work in tandem mounted inside the casing of the pump. In this system, only one gear is the driver while the other one is driven; this results in the driving gear rotating the driven one as the flow causes it to move.

Common Applications

  • Water
  • Light oils
  • Chemical additives

Internal Gear

With internal gear pumps, there are two gears, just like with the external pump, but the larger gear encases the smaller inner gear. Between the two gears is a crescent-shaped seal that fills in the gaps left by the two unequally sized gears. In this process, it creates a vacuum that traps the fluid between the gears, eventually forcing it to travel from the inlet to the outlet.

Common Applications

  • Asphalt and tar
  • Resins and polymers
  • Alcohols and solvents


A ge-rotor gear is a type of industrial peristaltic pump that uses two generated rotors. Much like the internal gear, rotor pumps have a smaller rotor with outward-facing teeth and a larger rotor with internal facing teeth. The smaller rotor rotates, causing the larger one to turn with it. Along with the movement originating from the smaller rotor, the materials that pass through the system push against the rotors themselves, causing an increase in speed and for materials to flow faster.

Common Application

  • Light fuel oils
  • Lube oil
  • Hydraulic fluid


Lobe pumps use a design that’s similar to external gears, but instead of gear teeth, they use rounded lobes. The main difference between lobes and external pumps is that the lobes don’t make direct contact with one another.

Common Application

  • Polymers
  • Paper coating
  • Soaps
  • Rubber and adhesives


Instead of the traditional gears we typically see, screw pumps—as the name suggests—incorporate an elongated screw into their flow design. Because of the length of the screw, the inlet splits off into two, pumping into either side of the screw; it then flows into a single outlet at the center.

Common Applications

  • Fuel injection
  • Lubricants
  • Hydraulics

Know What You’re Dealing With

When fitting a new pump, keep in mind the materials you intend to pump through the system. Something too viscous can clog a pump like external pumps, driving up operating costs and decreasing efficiency. Be aware of the different types of gear pumps and their applications before committing to a singular pump.