Hydraulika

Hydraulics, or hydraulika in several languages, is the branch of science and engineering that deals with the behavior of liquids under pressure and their use to transmit, control, and convert energy. It relies on the principle that pressure applied to a confined incompressible fluid is transmitted undiminished throughout the fluid (Pascal's law), allowing small forces to create large motions when transmitted through hydraulic cylinders and motors. A typical hydraulic system includes a pump, a fluid reservoir, valves, tubing or piping, and actuators such as cylinders or hydraulic motors; the fluid serves as the energy carrier, while the control components regulate direction, speed, and force.

History and development trace the concept to Blaise Pascal in the 17th century, with further practical machines developed in the 18th and 19th centuries, including hydraulic presses and Bramah pressure systems. Since then hydraulics have become essential in industry and transportation, enabling compact, high-load power transmission and precise control across a range of applications.

Applications of hydraulic systems are widespread. They are used to lift, push, pull, and steer in construction equipment (such as excavators and loaders), metal forming and stamping (hydraulic presses), aircraft control surfaces and braking systems, machine tools, and various process industries. Hydraulics offer high power density, smooth proportional control, and the ability to transmit force across distances, but they require careful maintenance, filtration, and thermal management to prevent wear, leakage, and contamination.

Fluids used include mineral oils, synthetic oils, and water-based emulsions, chosen for lubricity, lubrication, and compatibility with components. Safety and environmental considerations are important, given the potential for leaks and fire hazards with some fluids. Standards issued by ISO and SAE address the design, installation, operation, and safety of hydraulic systems.