Internal Gear Pumps    are one of the common types of hydraulic pumps. Talk to our experienced work technicians to make sure you find the right pump for your job. Understanding the internal working principle and characteristics of internal gear pumps can determine whether they are internal gear pumps. Great for your application.

Overview of internal gear pump

Internal gear pumps are very versatile, capable of pumping many different types of fluids over a wide range of viscosities and temperatures. Internal gear pumps use two gears to deliver fluid. The rotor gear is on the outside and the smaller idler is nested inside.

When the rotor (external) gear rotates, it drives the idler (internal) gear. When the idler gear is out of contact with the rotor gear, liquid is drawn into the pump and flows along the pump casing to the discharge side of the pump, where the gear teeth mesh together and force the fluid out of the pump.

What do they do
Internal gear pumps are ideal for high viscosity fluids. They are also useful for situations where low NPSH is required. Since there are only two moving parts, maintenance costs are low.

Their best application
This is just a short list of applications where an internal gear pump can be used.
Food (corn syrup, oil, nut butter, chocolate)
Dairy products
Personal care products (pastes, creams, soaps)
Extensive oils and lubricants
Paints, pigments, inks


What are they not suitable for?
Internal gear pumps are not suitable for large solids. Because of their small manufacturing tolerances, large solids can easily damage the pump. They can handle some small suspended solids in abrasive fluids, but be aware that this can cause pump wear and loss of performance.


Zhejiang Yongling Hydraulic Machine Co , Ltd   . is an excellent China company specializing in the production of internal gear pumps. If you need help choosing an internal gear pump or other hydraulic pump product for your application, please consult us.