Hydraulic oils, used in machinery to help lift heavy objects, also help open and close braking mechanisms as well as serving as a medium for heat transfer and lubrication. According to the National Aeronautics and Space Administration (NASA), Pascal's principle of physics allows for a non-compressible fluid--hydraulic fluid--to transmit forces from one part of the fluid to another. An essential component in a variety of machinery, hydraulic oils help automobiles, aircraft and heavy equipment perform some of their most basic mechanical functions.
Hydraulic auto braking systems channel hydraulic oils through a network of cylinders and tubes to exert stopping pressure against brake pads or shoes. Hydraulic oil makes it possible for the braking mechanism to exert the steady, sustained pressure necessary for smooth stopping.
Hydraulics were first used for auto braking in the early 20th century. The advent of hydraulic automotive brakes made several later braking innovations possible, including self-adjusting brakes and anti-lock brakes.
Backhoes, excavators, bulldozers and other heavy-duty equipment utilize hydraulic oils to perform work. Hydraulic oils are transmitted through hydraulic cylinders and motors to generate the force needed to lift heavy objects and move earth. Damage to hydraulic equipment, including fluid leaks, pressure inconsistencies and other malfunctions, compromise the ability of a machine to perform work.
Not all heavy machinery uses hydraulic oils, however. Many others rely on pneumatic technology instead, which uses gas to generate and transmit force.
According to the Florida International University (FIU) Aeronautics Learning Laboratory, hydraulics are used to operate a variety of aircraft mechanisms including landing gear, wing movement systems and engine boosters.
In much the same way as automobiles and heavy equipment, aircraft use pumps, cylinders and motors to store energy generated by the engine in hydraulic oil. Pressurized hydraulic oil is then channeled to mechanisms that require force to operate correctly.
