From control surfaces in aircraft to heavy construction equipment, hydraulics are a fundamentally important part of a lot of modern machinery. Without hydraulics, it’d be very difficult to transmit a lot of the energetic forces that motors and engines provide. Today, let’s take a look at some of the mechanics behind this engineering marvel.

Hydraulics in a nutshell

The word “hydraulics” comes from the Greek words hydro (water) and aulos (pipe). It refers to the use of liquid fluids to transmit mechanical work, by forcing them at high pressures through hoses and pipes.

These fluids are usually oil-based because the working temperatures of hydraulic systems can be higher than the boiling point of water, and also because they naturally lubricate their chambers.

Hydraulic fluids – and really, liquids in general – have extremely low compressibility, which means that they’re governed by a principle known as Pascal’s Law, which states that a fluid in a closed system, when pressure is applied, will transmit the same pressure equally throughout the closed system.

This, in turn, means that when hydraulic fluid is pushed by a hydraulic motor or cylinder, it reliably and directly transmits force from one point to another, without any delay or “springy” feeling.

The nature of gas vs. liquid

Hydraulics shares the same principles as pneumatics, which uses pressurized air or other gases, rather than liquids. While both gases and liquids are considered fluids, they differ in that gases are compressible.

Because gases can be compressed, any force transmitted through pneumatic systems is slightly absorbed by the compression of the gas. While this means that pneumatic systems tend to be relatively reliable because the working gases absorb any sudden forces that could damage machinery, this also means that they’re less responsive, and are capable of transmitting less energy.

In general, pneumatics are for fast and lightweight tools, while hydraulics are for very heavy loads or loads that require quick responses.

Where you see hydraulics at work

Hydraulic systems are found nearly everywhere. One example that’s close to home is the power steering that’s found in modern automobiles. If your car’s steering wheel were connected directly to the steering linkages, it’d require a lot of effort to rotate the heavy wheels. Power steering instead connects the steering wheel to a hydraulic system and turning the wheel controls the flow of fluid that can turn the wheels either way.

Another common example is found in the hydraulic systems that control the flaps, ailerons, elevators, and other control surfaces on aircraft. These systems need to be extremely reliable to ensure that a plane doesn’t fall from the sky, and must have the power transmission characteristics to handle the aerodynamic forces that are part and parcel of travelling at almost a thousand kilometres per hour through the air.

Hydraulics in Perth

Hydraulic systems in principle are reliable, but you need a reliable manufacturer, in turn, to get the most out of your machinery. For top-performing, dependable hydraulic solutions in Perth, Alcaro Hydraulic Services offers mobile services in the region to mining, agricultural and industrial applications. From custom-built machines to labour needs and repair services, Alcaro provides everything you need, exactly at the sites where you need them. Contact us now and ask about our 12-month warranty!