Hydraulics is a concept with a very broad meaning, referring to many situations and processes, which, however, share a certain common element, which is water (hydraulikk pumpe) . In today’s machines and devices, in order to increase their capabilities, this type of liquid is also replaced with other, with greater possibilities of compression and expansion, which is the basis of hydraulic drives. In relation to such applications, the field referred to as power hydraulics is used.
Power hydraulics and its characteristics
Force hydraulics is understood as the field of hydraulics that uses pressure of compressed liquid to control and drive various machines and devices. The basis of such a drive is a system of construction elements forming a closely cooperating unit transferring energy to a specific element responsible for lifting, moving or making any move. The beginnings of power hydraulics date back to ancient times, when water supply systems, including the famous Roman aqueducts, were established and perfectly functioning (pneumatikk) . Today, hydraulically driven devices use oils with a much higher density, thanks to which the obtained energy can be higher, and the device works more efficiently. The possibilities of hydraulic drives can be huge. A small cylinder equipped with a hydraulic pump can lift up to several hundred tons. The power of the device depends mainly on the capacity of the oil tank, which generates energy from pressure during compression and expansion of the liquid. Contrary to appearances, the tank does not have to be big at all, because it requires only about 1 dm3 for a cylinder or a 200 ton press.
The essence of the operation of hydraulic devices is a two-stage process, which consists of:
creating a vacuum by means of mechanical force (eg pump lever), which causes suction of oil from the tank to the entrance,
injecting fluid into the hydraulic system and creating a pressure by forcing its motion.
The pressure level to be reached must be large enough to overcome the resistance of the connected device (ventilblokk) .