What Is a Gear Pump?

If you need to move liquid from one place to another, you’ll probably want to use some type of pump. There are various types of industrial pumps that can do the job. A gear pump, for instance, is an excellent example of one such industrial pump!

A gear pump is a rotary positive displacement pump that offers continuous service delivery. Using gear meshings, fluid energy is created from mechanical energy, which creates zero suction. The space at the center of the gear meshing then carries fluids toward the pump’s output. This type of pump doesn’t require priming and can work efficiently for extended periods. 

Applications for Gear Pumps

Why would you use a gear pump? These types of pumps are used to pump oil, resins, paints, and food products that have a high viscosity. These are ideal options when your business requires precise measurements or high-pressure output. Gear pumps are also preferable when there is an irregular supply because their pressure won’t impact output much. 

Some examples of applications for these pumps include the following.

  • Automotive oils and fuels
  • Solvents and alcohol
  • Hydraulic oils
  • Paints, polymers, and resins
  • Edible foods such as peanut butter, corn syrup, and animal food 
  • Liquid soap

How Gear Pumps Work

A gear pump works through the action of rotating gears or cogs to transfer fluids. When the rotating elements create a liquid seal with the interior casing, a suction is created at the pump’s inlet. Fluid that has been drawn into the pump is enclosed between the rotating gears, and then it is transferred to the discharge outlet. 

Components of a Gear Pump

Here are the seven main components of a gear pump.

1. Inlet Section

This part of the pump receives liquid into the pump. It is connected to the pump’s main housing, where the gears are located. 

2. Prime Mover

A gear pump uses this to drive the shaft containing the power gear. This can be powered by an electric motor, IC engine, or manually. 

3. Drive Gear

The power gear, or driver, is connected to the prime mover. The pump’s main motor causes the gear to rotate. 

4. Idler

The idler, also called the driven gear, meshes with the driver gear and also rotates inside the pump. 

5. Housing

The housing of the pump contains both the driver gear and the idler. 

6. Outlet Section

The outlet section of a gear pump is the part of the pump where liquid exits the mechanism. 

7. Pressure Relief Valve

There is a safety valve installed on the pump’s outlet section that can release fluid if there is excess pressure to prevent any damage to the pump. 

Different Types of Gear Pumps

There are several different types of gear pumps. The most common types you’ll find are either external or internal gear pumps. But, it’s possible you might run into a few others that can accommodate your needs. 

External Gear Pump

An external, or helical, gear pump is used when viscous fluid is transferred at low RPMs and where there is a requirement for the smooth discharge of fluid. In this type of pump, the gears are mounted on top of each other within the head, and one is driven by the pump’s motor. The gears are timed to coincide with fluid moving into the open cavities, which rotates between the gear teeth and casing, and then is moved to the pump’s outlet. 

Because of its lower speed, this pump doesn’t produce much noise. Also, the “helical” parts are offset at an angle inside the head of the pump, and a second set of gears are used to keep the system balanced. An external gear pump cannot handle any solid materials. 

Internal Gear Pump

An internal, or eccentric, gear pump design is similar to an external one in that the spaces between the gears will be filled with liquid. However, the interlocking gears in this type of pump are different sizes, with one rotating inside the other. The larger gear is the internal gear, or the rotor, and the smaller is the idler. 

The bushing and pinion attached to the pump’s casing hold the idler in place, which is mounted off-center. As the gears rotate and liquid fills the space around them, trapped pump fluid moves from the inlet side and is discharged under pressure to the outlet. This type of pump can handle small solids. 

Benefits of a Gear Pump

Why should you use a gear pump? Here are some of the biggest advantages of these types of pumps.

  • Compact, simple pumps with few moving parts
  • Low maintenance costs
  • Low upfront costs
  • Pumps are self-priming
  • Flow is proportionate to speed, so there is a predictable flow rate
  • Can generate high pressure, up to 3,000 psi
  • Can pump highly viscous liquids that centrifugal pumps can’t handle
  • Low probability of leakage when pumping high viscous liquid
  • Can be run in both directions
  • Low probability of contamination

Limitations of a Gear Pump

If you plan to use a gear pump, it’s also important to understand the potential limitations of these machines. These include the following.

  • Some gear pumps can be noisy
  • Size is limited, so they can’t be used for large bulk flow rates
  • Use meshing gears, so they won’t work with friction fluid

Learn More About Gear Pumps with C&B Equipment

Now you know quite a bit about gear pumps, how they work, and their various applications. If your business is looking for a quality gear pump, C&B Equipment can help. 

Our team of professionals can help you select the right pump and keep your gear pump operating as it should. We have decades of experience installing, maintaining, and repairing all types of industrial pumps. Contact us today to find out how our services can help your business boost its efficiency and profitability.

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