What does a gear pump do?

The gear pump is a mechanical delivery device used for precise and controlled metering of liquids or viscous materials. It consists of two intermeshing gears that rotate in a housing. As the gears rotate, the material to be conveyed is trapped between the teeth and transported from the inlet side to the outlet side. Known for its high accuracy, repeatability and reliability, the gear pump is used in various industries where precise metering is required to ensure product quality and process control.

How does a gear pump work?

A gear pump in metering technology operates on the principle of two intermeshing gears rotating inside a housing. Listed below is a basic explanation of how such a gear pump works:

Inlet Phase:
At the beginning of the pumping cycle, both gears are in close contact with each other and the pump chamber is filled with the material to be pumped. The inlet valve is open and the material is fed to the pump through a feeding system.

Metering phase:
As the gears rotate, the gaps between the teeth on the material inlet side each fill with material. On the material outlet side, the material is displaced from the pump via the engagement of the teeth of one gear in each case in the tooth gaps of the other gear, and is thus conveyed.

Conveying phase:
As the gears continue to rotate, the displaced material is conveyed into the metering area toward the outlet. The outlet valve opens and the material is discharged from the pump into the metering system or metering point.

Repeat:
This cycle of inlet, metering, conveying, and outlet is repeated continuously to provide the desired amount of material to be dispensed. The speed and metering amount can be precisely adjusted by controlling the speed of rotation of the gears.
It is important to note that accurate metering in gear pumps depends on the precision of the gears and the control of the rotational speed. Gear pumps offer the advantage of relatively constant and low-pulsation metering, which is beneficial in many metering applications.
Gear pumps are used in a variety of industries, including chemical, food processing, oil and gas, pharmaceutical manufacturing and many others where precise metering of liquids or viscous materials is required.

What are the advantages of a gear pump?

Gear pumps offer numerous advantages in various applications, especially in situations where precise metering or reliable fluid delivery is required. Some of the advantages of gear pumps are listed below:

High accuracy:
Gear pumps offer precise metering of liquids or viscous materials because the gears mesh closely and deliver a well-defined volume per revolution.

Low pulsation:
Gear pumps typically produce a uniform and low level of pulsation in the fluid flow, which is important in applications involving delicate instruments or equipment.

Versatility:
They can be used for a wide range of fluids and viscous materials, including chemicals, oils, lubricants, paints, adhesives and more.

Reliability:
Gear pumps are typically reliable and have a long service life. They require less maintenance and have low downtime.

Easy maintenance:
Gear pump maintenance is often straightforward because they have fewer moving parts and are easily accessible.

Efficiency:
Gear pumps are usually energy efficient, achieving high metering rates with low energy consumption.

Good self-priming:
They can prime fluids from low levels or against a slight vacuum, which is useful in some applications.

Low maintenance costs:
Because of their reliability and low need for spare parts, long-term maintenance costs are often low.

Adaptability:
They can be adapted for various applications and environments, including high-temperature and high-pressure applications.

Compact design:
Gear pumps often have a compact design and can be installed in limited space.

Choosing the right pump depends on the specific requirements of an application. In cases where precise metering and low pulsation are important, gear pumps are a popular choice. They are used in a variety of industries, including chemical, food processing, oil and gas, pharmaceutical manufacturing and many others.

What are the different types of gear pumps?

Gear pumps can be divided into different types according to the design and application. The main types of gear pumps can be divided as follows:

Internal gear pumps:
In internal gear pumps, the input gear (internal gear) is located inside the casing and engages with the output gear (external gear). These pumps are often used in high viscosity applications.

External gear pumps:
In external gear pumps, both the input gear and the output gear are outside the casing. The gears rotate on the same axis, pumping the material.

Internal Gear Metering Pumps:
These pumps are specifically designed for metering and dispensing applications. They often use two intermeshing internal gears and provide precise metering of fluids.

External gear metering pumps:
These pumps are similar to internal gear pumps, but are used specifically for metering and dispensing applications. They are known for their accuracy in metering.

Gear pumps with internal and external gears:
Some gear pumps use both internal and external gears in their design to meet specific requirements such as high viscosity or high pressures.

Multiple gear pumps:
These pumps have multiple pairs of gears that operate simultaneously to achieve higher metering performance. They are often used in industrial applications where large volumes of liquid are required.

Gear pumps (gerotor pumps):
Gear pumps, also known as gerotor pumps, use an internal gear and an external gear with a special geometry. They offer a good combination of performance and compactness.

Twin-screw pumps:
These pumps use two intermeshing helical gears to move fluids. They are used in high flow and low viscosity applications.

Gear pumps for high-pressure applications:
Specially designed gear pumps can produce very high pressures and are used in applications such as high-pressure cleaners and water jet cutting machines.

Choosing the right gear pump depends on the specific requirements of an application, including the type of material being pumped, metering accuracy, pressure and temperature range, and other factors. Each type of pump has its own advantages and disadvantages and is better suited for certain tasks.

What are typical applications of a gear pump?

Gear pumps are used in a wide variety of applications, especially when precise metering is required. Here are some typical applications of gear pumps:

Medical technology:
Gear pumps are used in medical technology, for example, to reliably process potting materials, such as for the production of artificial lungs or dialysis filters.

Automotive industry:
Gear pumps are used in the automotive industry to process lubricants, adhesives and sealants.

Electronics industry:
Metering systems with gear pumps are often used in the potting of electronic components to ensure precise material discharge.

These examples show that gear pumps are widely used in a variety of industries and applications where precise metering and high accuracy are required. They are often used in combination with flowmeters and control systems to further improve metering.

Which METER MIX products are equipped with a gear pump?

Our LiquidFlow series is equipped with gear pumps and covers both the precise application of small beads and large discharge volumes. This is complemented by our PasteFlow series, which can be used to apply highly viscous materials.

LiquidFlow 30
LiquidFlow 40
LiquidFlow 50

Dispensing systems with gear pumps for highly viscous materials
PasteFlow 20
​​​​​​​PasteFlow 200​​​​​​​

Material dispensed by continuous flow
METER MIX Liquidflow 2PC

LiquidFlow 2

Versatile machine for accurate dispensing of small beads

METER MIX Liquidflow 30m

LiquidFlow 30

Precision gear pump technology for low-mid flow applications

METER MIX Liquidflow 40

LiquidFlow 40

Mid-range gear pump technology for medium flow applications

METER MIX Liquidflow 50A

LiquidFlow 50

High-level machine for larger flow production demands

Material dispensed by continuous flow
meter-mix-pasteflow-20g

PasteFlow 20

High-level machine for dispensing beads of high-viscosity material directly from 20 ltr. drums

meter-mix-pasteflow-200g20

PasteFlow 200

High-level machine for dispensing beads of high-viscosity material directly from 200 ltr. drums