Gear pumps are used as hydraulic generators in hydrostatic circuits.
Description and use
HP pumps are divided into four dimensional groups. They are pumps with constant geometric volume and single, simple, double or multiple drive direction. The suction fluid flow rate must be max. 2.5 m/s; in this case, the pumps can work continuously with a suction pressure between (-0,2) and (0,5) bar and a discharge pressure according to the leaflets. The pumps can be equipped with flow and pressure controllers upon request. They are used in hydraulic systems or groups and in hydraulic circuits of machinery, agricultural machinery, machine tools etc.
HYDRAULIC VANE PUMP
The most common types of vane pumps are with fixed flow which generate flow with a set of vanes that slide radially inside a rotor provided with channels. They rotate in an elliptical chamber. The elliptical chamber is named a ring and, due to its shape, it produces volume differences between the adjacent vanes that create the pumping action when the rotor is started. Most new models of vane pumps form the pressure chamber with two pressure plates that fit the rotating group on the sides. This assembly bears the name of cartridge and makes it easier to repair it.
HYDRAULIC AXIAL PISTON PUMPS
Axial piston pumps are another variant of piston pumps in which the pistons are axially disposed, so they are parallel to the axis of rotation of the rotor (the block), the active movement of the pistons being made either by an inclined or fixed disc, or by a frontal cam. Thus, the pistons have the great advantage of greatly reducing the gauge of the pump and at the same time achieving a constant moment of inertia through the symmetry of the rotating masses, which allows their operation at angular speeds superior to other types. In view of these qualities, to which the good stability of the movement to low speeds as well as the ease of adjusting the active volume are added, priority is given to them, being the most common types of volumetric machines used in hydraulic drive, which also applies to the driving systems of machine tools. The main parameters of these types of pumps are: pressures between 150 and 500 bar, even higher, moments up to 800 – 900 daN × m, powers up to 3500 kW, flows up to 900 l/min, maximum speeds to pumps up to 3000-4000 revs/min.
HYDRAULIC RADIAL PISTON PUMPS