For truck-mounted hydraulic systems, the most common design in use may be the gear pump. This design is usually characterized as having fewer moving parts, being simple to service, more tolerant of contamination than various other designs and fairly inexpensive. Gear pumps are fixed displacement, also known as positive displacement, pumps. This implies the same volume of movement is produced with each rotation of the pump’s shaft. Gear pumps are rated in conditions of the pump’s optimum pressure rating, cubic in . displacement and maximum insight speed limitation.
Generally, gear pumps are used in open center hydraulic systems. Gear pumps trap essential oil in the areas between the teeth of the pump’s two gears and your body of the pump, transport it around the circumference of the apparatus cavity and then push it through the store slot as the gears mesh. Behind the brass alloy thrust plates, or 
use plates, a small amount of pressurized essential oil pushes the plates tightly against the gear ends to boost pump efficiency.