Gear Pumps


Gear Pumps: Excellent At Handling High-viscosity Liquids With A Pulse-free Flow

With over 25 years of experience, Hunter Pumps Industrial is an industry leader for end-to-end industrial pump solutions across Australia. Specialising in gear pumps, we handle fluids with high thickness efficiently.

Our large range of services and top-quality products make us the best choice for all your pumping needs. We are committed to delivering reliable performance and smooth, pulse-free flow in all our applications.

Key Differentiators of Air-Operated Diaphragm Pumps

Gear Pumps Features and Benefits

Industries and Applications

Gear pumps are ideal for high-viscosity fluids with few suspended solids. These fluids, including paints and soaps, can cause damage to a gear pump’s parts due to tight mechanical clearances, reducing pump efficiency and lifespan.

Gear pumps are widely used in different industries and applications, including:

Common applications include:

What is a Gear Pump?

A gear pump, a type of rotary positive displacement (PD) pump, is expertly designed to move fluids, including oils, adhesives, and paints. It achieves this by repeatedly enclosing a fixed volume of these high-viscosity fluids within its interlocking cogs or gears. The gear pump then utilises a cyclic pumping action to transfer the fluid out of the pump, creating a vacuum force that moves the liquid efficiently. The gear pump ensures a smooth, pulse-free flow that is proportional to the rotational speed of its gears, offering reliable performance across various applications.

How Does a Gear Pump Work?

Gear pumps utilise the motion of rotating gears to transfer liquids. A gear pump works based on the principle of positive displacement. Here’s how they work:

Understanding how gear pumps work showcases the brilliance of engineering in creating fluid movement systems.

For reliable and efficient gear pumps, consider Hunter Pumps, your go-to source for all your pumping needs.

Types of Gear Pumps

Understanding how gear pumps work showcases the brilliance of engineering in creating fluid movement systems.

Types of Gear Pumps

External gear pumps consist of two identical interlocking gears. Liquid enters the pump’s cavities, where it is captured by the gear teeth. It then flows from the inlet to the discharge, where its volume is reduced and the liquid is expelled from the pump under pressure. External gear pumps are commonly used in various applications.

Internal Gear Pumps

With two interlocking gears of different sizes, the smaller one spins inside the larger one. The fluid flows through the pump just like in an external gear pump, but the gears interact at specific points in the process. External gear pumps have various common applications, such as:


The following table provides a comparison between external and internal gear types:

 External Gear PumpsInternal Gear Pumps
Rotor AssemblyExternal gears form rotor assemblyAssembly consists of an internal and an external gear in the rotor
Rotor SupportFour bearings support rotor shaftsMaximum of two bearings provide rotor support
DesignCompact pump designDesign can be bulky and less efficient for top-tier models
Outlet Sizes & CapacitiesLarge outlet sizes, high capacitiesOutlet sizes are small with medium to low capacities
Gear DesignsSpur, helical, herringboneSpur gears are used exclusively, with a wedge needed for gear separation
Ideal UsageIdeal for medium/low temperature, high pressure pumpingSuitable for high temperature, moderate pressure and low capacity pumping

If you’re not sure if gear pumps are the right fit for you or if you want to learn more about the types of gear pumps we offer, feel free to reach out to our expert team. You can get in touch with us anytime!


Hunter Pumps: Your Trusted Gear Pumps Provider & Servicer in Australia

Hunter Pumps Industrial is your trusted pump solutions provider across Australia, offering an extensive range of Gear Pumps. Our rotary pumps are the best equipment for dispensing operations, filling, and general transfer. These pumps create a pulseless flow, moving fluid using built-in gears, perfect for handling viscous and abrasive fluids in various industrial applications. We source our Gear Pumps and spare parts from the world’s most trusted manufacturers. And, we have trained, experienced staff ready to provide quick and effective servicing.

Gear pumps are excellent at handling high-viscosity liquids such as oils, paints, resins, or foodstuffs. Hunter Pumps supplies the best quality gear pumps from our trusted brands, and. also designs, tests, services and repairs all gear pumps.

Contact us today at Hunter Pumps Industrial for reliable, efficient Gear Pump solutions and expert servicing across Australia.

Ask our team of specialists

Get in touch with Hunter Pumps to schedule your free pump assessment

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Frequently Asked Questions (FAQs)

No, operating gear pumps without fluid can lead to damage even in brief durations.

The gears need fluid for lubrication—without it, they can quickly deteriorate. Similarly, the mechanical seal needs fluid for cooling and lubrication. Without fluid, it can overheat, crack, and cause leaks, potentially leading to motor damage.

An integral bypass valve acts as a temporary safety measure against overpressure. But for long-lasting protection, it's a good idea to have an external bypass that redirects to the fluid source tank. The valve typically opens and recirculates fluid within the pump head when pressure exceeds about 10% of the working pressure.

Yes, all pump types, including gear pumps, can cavitate due to inadequate suction pressure, irrespective of their operating speed.

Pump selection primarily depends on the fluid type, required flow rate, and application's pressure requirements. Fluid viscosity, temperature, and achievable pressure also play a role. There's often overlap between different models, with the final choice based on efficiency and cost-effectiveness. Our team at Hunter Pumps can assist in making the right selection.