External gear pumps are completely different from internal gear pumps.
Depending on the application, the external gear pump can be single or dual configuration with various gear types (spiral, herringbone or spur gear). The pump is known for its tight tolerances, enabling a large amount of flow control and high pressure capability.

How it works
The external gear pump works in a similar way to the internal gear pump, because the two gears mesh and mesh with each other to generate flow. Unlike the gears in the internal design, the gears do not rotate in the same direction, but external gear pumps usually have two identical gears that rotate relative to each other. When the gears are disengaged, they draw in liquid. Then, before they re-engage, they hold the liquid inside as they lean against the housing, forcing the fluid to flow out of the discharge port.

What do they do
The tight internal clearance makes the external gear pump ideal for applications where hydraulic, metering and flow control are important. They can handle both high-viscosity and low-viscosity liquids, but the speed of the pump must be adjusted appropriately to obtain the proper viscosity. They are suitable for all liquids and are relatively quiet pumps.

What are they not suitable for
Pumping any type of solid liquid through an external gear pump is not a good idea. Abrasives and high temperatures are also poor choices for this pump. Basically pumping anything that causes premature pump wear is a bad idea because any wear will require replacement or reconstruction of the pump due to its tight tolerances.

Their best application
Here is a short list of some of the best applications for this pump:
Fuel
lubricating oil
Dosing chemicals or polymers
Low-capacity transmission
Acids

External gear pumps are ideal for many applications. Think this might work for you? Talk to our experienced engineers to make sure you find the right pump for your job.

As a professional    Gear Pump Manufacturers  and     Gear Pump Suppliers    , Taizhou Yongheng Hydraulic Machinery Co., Ltd. can provide you with high quality products and services. Eternal Hydraulics is committed to becoming a global one-stop shop for global hydraulic products, with professional hydraulic solutions and high-quality products to meet the needs of each customer. The company firmly believes that "only the best can satisfy the best", and has become the first choice of hydraulic components for all customers worldwide. https://www.xjetl.com/product/gear-pump