There are few technologies as widely accepted and implemented as hydraulics. You'll find hydraulic technology applied everywhere, but it is a dominant force in heavy machinery like backhoes and other heavy equipment, though it has applications within the automotive industry, as well. Hydraulic fluid provides enormous power, much more than a comparable electric motor.
External Hydraulic Pumps: The hydraulic gear pump has become an inexpensive, efficient fixture on hydraulic equipment. It provides a simple solution for providing the large amount of power needed for the lifting and digging that these large machines are designed for. An external hydraulic gear pump works on the principle that two spinning gears will propel the fluid from the reservoir, through the tubes and hoses to the hydraulic motors and engines, which will do the heavy work.
In the automotive industry, the hydraulic gear pump has a couple of applications. The first and most pervasive is in the oil pump with which almost all vehicles are equipped. It works through a pair of rotors, or gears, one set inside the other. The inner gear is offset from the outer, so that as the pair rotates, a gap forms. This gap creates a vacuum, which moves the oil through the pump and on to the engine, where it is needed.
Gear pumps are also used in automatic transmissions. The types of pumps used are very similar to oil pumps. They also operate on the same principle of positive displacement. Hydraulic gear pumps are used within automatic transmissions because of the benefits provided over a conventional electric motor and because they can be made to take up very little space. Many of these pumps can be put into a transmission to provide excellent fluid flow for the transmission, ensuring proper operation for a long life of hard use. The amount of fluid that is dispersed through the different channels and cavities of the transmission is controlled by the number, size and speed of the hydraulic gear pumps within the transmission.
The two gears within a hydraulic gear pump are what provide movement to the liquid in question. One gear is a simple idler gear, which does nothing but spin when turned. The other gear is called the driver, or drive gear. This is the gear that is responsible for turning both itself and the idler gear. The spinning creates vacuum and fluid is moved around the chamber in the gaps between the teeth of the two gears; no fluid moves between them. This is in contrast to the style of hydraulic gear pump used as an oil pump in automotive engines, when the oil moves between the two gears, but not around them.
The uses of the hydraulic gear pump are many and varied. It has become an integral element in almost every industry on the face of the earth; with this technology, you can literally move mountains or ensure that your vehicle continues moving for a long time to come. The hydraulic gear pump has made many things possible that would otherwise be all but impossible.