Search results
An external gear pump moves a fluid by repeatedly enclosing a fixed volume within interlocking gears, transferring it mechanically to deliver a smooth pulse-free flow proportional to the rotational speed of its gears.
Gear pumps are also widely used in chemical installations to pump high-viscosity fluids. There are two main variations: external gear pumps which use two external spur gears, and internal gear pumps which use an external and an internal spur gear (internal spur gear teeth face inwards, see below).
The external gear pump has two identical gears (power and driven gears) that rotate in opposite directions. Usually, the power gear is run by an electric motor or IC engine that further rotates the driven gear.
External gear pumps simply use the actions of gears to transfer different types of fluids. In this article, we will illustrate the main features of external and internal gear pumps, the way they work, and other technical information.
External gear pumps are one of the most common types of gear pumps. They consist of two gears—one driving gear and one driven gear—both of which are external to the pump housing. The driving gear is typically connected to a motor or an engine and rotates, driving the driven gear.
External gear pumps are usually available with either spur gears, making them too bi-directional, or herringbone gears, which are for particularly viscous fluids but do not allow reversible flow.
External gear pumps have close tolerances and shaft support on both sides of the gears. This allows them to run to pressures beyond 3,000 psi / 200 bar and also provide greater flow control and a more reliable measure of liquid passing through a pump.
