Gear Pumps and How Do They Work?

Blog | June 29th, 2017

Gear pumps operate according to a direct coupling principle. In other words, two mechanical components, gears, are meshing inside a shared housing. The primary drive mechanism in this conjoined arrangement is powered by a motor or some other prime mover, then the drive shaft on that mechanism extends into a gearing chamber. A gear is locked to that shaft. It rotates, mates with the gearing teeth of a second driven gear, and pumping action commences.

Basic Fluid Impeller Mechanics

In machine architectural terms, the two married gear wheels are rotating synchronously, as determined by the most basic mechanical principles. However, it is in-between the two spur gears that the fluid conveyance process takes place. In this area, where the locking and unlocking gear teeth engage then disengage, the hydraulic oil is trapped then carried through the gear housing. If a hypothetical cross section could be cut into the gear pump while it’s working, you’d see the hydraulic stream moving from the inlet port, through the dual gearing arrangement, and forced out of the housing via the outlet port.

Gear Pumps: A Closer Inspection

The last paragraph introduced you to the principles that shape this hydraulic pumping device. In practice, however, this duel-geared pumping configuration operates a little differently. First of all, the fluid isn’t conveyed through the middle section of the meshing gears. In fact, the gears engage in such a way that two fluid streams branch, flow around the exterior rim, through the interior contours of the impeller housing, and out the “fluid out” pipe. In following this path, the fluid volume makes full use of the pump housing. As for the dual gears, the side-by-side spur wheels, their teeth are shaped to facilitate fluid conveyance, not for mechanical coupling. Because of this geometry, the spur wheels use contoured teeth, and sometimes they even reduce the amount of teeth employed on each wheel. That latter feature varies as power output and fluid viscosity alters.

Hydraulic gear pumps are used as volumetrically efficient fluid pumps. They can also be repurposed as lubrication pumps, chemical process impellers, and oil pumps. Built to close tolerances and featuring large-capacity inner workings, the pumps run on high pressures, drive massive loads, and operate at varying rotational velocities. Now, although there are more than a handful of applications that exist to take advantage of those impressive features, that high operational pressure feature does shift this product family firmly towards hydraulic equipment empowerment.

Mobile Hydraulic Specialties Pty Ltd

Factory 89, 38-40 Popes Road
Keysborough, Victoria, 3173

Phone: (03) 9798-6511

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Mobile Hydraulic Specialties Pty Ltd

Phone: (03) 9798-6511
Address: Factory 89, 38-40 Popes Road, Keysborough, Victoria, 3173