An internal gear pump is a gear pump featuring a drive gear with inward facing teeth called a rotor. This rotor turns an offset gear with fewer outward facing teeth called an idler. A crescent shape protruding from the head of the pump creates this offset and seals the pumping cavities formed between the gear teeth. Click here to view our How it Works video on this subject.

This pumping principle was invented by Viking Pump over 100 years ago.