For truck-mounted hydraulic systems, the most common design in use may be the equipment pump. This design is definitely characterized as having fewer moving parts, being easy to service, more tolerant of contamination than other designs and relatively inexpensive. Gear pumps are set displacement, also known as positive displacement, pumps. This implies the same volume of stream is created with each rotation of the pump’s shaft. Gear pumps are rated in conditions of the pump’s maximum pressure rating, cubic inch 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 your teeth of the pump’s two gears and the body of the pump, transportation it around the circumference of the gear cavity and then force it through the outlet port as the gears mesh. Behind the brass alloy thrust plates, or put on plates, a small amount of pressurized 
oil pushes the Gear Pump china plates tightly against the apparatus ends to boost pump efficiency.