Hydraulic

Hydraulic refers to the use of liquid under pressure to transmit power and control motion. The field, also called hydraulics or fluid power, relies on Pascal's law: in a confined, incompressible fluid, pressure is transmitted equally in all directions. This enables a small force applied to a small piston to generate a larger force on a bigger piston, allowing powerful work in compact packages.

A hydraulic system typically includes a reservoir, a pump, a network of hoses or tubes, actuators such as cylinders or hydraulic motors, and valves to control flow, pressure, and direction. Fluids used are usually mineral oils or synthetic oils, though water-based fluids are used in some applications. Seals, filters, and coolers are common, and accumulators may store energy.

Applications span construction and mining equipment (excavators, loaders, cranes), manufacturing presses, and machine tools, as well as flight control systems in aircraft and hydraulic braking and steering in many vehicles. In energy sectors, hydraulic fracturing uses high-pressure fluid to create fractures in rock to release hydrocarbons.

Advantages include high force output with relatively small components, fine control of speed and position, and straightforward scaling by changing piston sizes. Drawbacks involve potential leaks and fluid contamination, thermal buildup, and environmental or safety risks if fluids are released. Effective design emphasizes proper material compatibility, leak containment, filtration, and cooling.