is a system designed to transmit power through a liquid
medium, permitting multiplication of force in accordance with Pascal’s law,
which states that "a pressure exerted on a confined liquid is transmitted
undiminished in all directions and acts with equal force on all equal
areas." Hydraulic systems have six basic components: (1) a reservoir to hold
the fluid supply; (2) a fluid to transmit the power; (3) a
pump to move the fluid; (4) a valve to
regulate pressure; (5) a directional valve to control the flow, and (6) a
working component — such as a cylinder and piston or a shaft rotated by
pressurized fluid — to turn hydraulic power into mechanical motion.
Hydraulic systems offer several advantages over mechanical systems: they
eliminate complicated mechanisms such as cams, gears,
and levers; are less subject to wear; are usually more easily adjusted for
control of speed and force; are easily adaptable to both rotary and linear
transmission of power; and can transmit power over long distances and in any
direction with small losses.