External Gear Pump

An external gear pump is a type of rotary positive displacement pump that uses two identical external gears arranged side-by-side. One gear is driven by the power source (the drive gear) and the second gear (the driven gear) meshes with it. As these gears turn, the liquid is carried in the spaces between the gear teeth and moved through the pump from the inlet to the discharge port.

1. What is an external gear pump?
It is a rotary, positive displacement gear pump that contains two matching external gears—one driven directly and the other turned by the first—that transfer liquid by trapping and conveying it between the gear teeth.

2. How do external gear pumps work?
As the gears rotate against each other, they separate at the inlet side, creating space that draws liquid in. The liquid becomes trapped between the gear tooth cavities and the close-fitting casing and is carried around the housing. At the outlet, the gears mesh again, pushing the liquid out through the discharge port.

3. What are external gear pumps used for?
Because the gears are supported on both sides, these pumps are capable of sustained high-pressure operation, making them suitable for tasks such as hydraulic systems, pipeline injection, and other industrial applications requiring reliable high-pressure fluid transfer.