hüdraulika

Hüdraulika, or hydraulics, is the science and technology of transmitting power through incompressible liquids to perform work. It encompasses fluid mechanics, fluid power, and the design and analysis of hydraulic systems that convert pressure and flow into motion and force.

The core principle is Pascal's law: pressure applied to a confined liquid is transmitted undiminished in all directions. This allows small input forces, via modest pistons, to multiply into large output forces. The available power depends on the pressure and the volumetric flow rate, while losses arise from friction, leaks, and heat.

A typical hydraulic system includes a reservoir of hydraulic fluid, a pump, actuators (pistons and hydraulic motors), control valves (directional, relief, and flow-control), sensors, filters, hoses or tubes, and sometimes heat exchangers to remove excess heat.

Control is achieved through open-loop or closed-loop arrangements. Servo and proportional valves provide precise position or force control, often with feedback from sensors. Efficient operation requires proper fluid selection, filtration, cooling, and maintenance to minimize contamination and wear.

Applications span industrial machinery, construction equipment, aerospace and automotive systems (brakes, power steering, flight controls), marine systems, and robotics. Compared with pneumatics, hydraulics deliver higher forces and precise motion at relatively high load, but require careful handling of fluids and containment.

History: The concept dates to early experiments with pressurized liquids, and the hydraulic press became widely used after the 1795 Bramah invention. The development of reliable pumps, valves, and fluids in the 19th and 20th centuries expanded hydraulic power into countless industrial and mobile applications.

Environmental and safety considerations include fluid leaks, fire or environmental hazards with certain oils, and the need for biodegradable fluids and proper containment. Standards govern fluid cleanliness, pressure, and safety.