What Are Hydraulics Used For?
You've probably used a hydraulic device today without even realizing it. Everywhere you look there is a machine that uses hydraulics in some way. Cars, buses, airplanes, cranes, and forklifts are only a small portion of the machines that we use everyday that have hydraulics to help them function.
Cars use hydraulics systems for the brakes and shock absorbers. Some buses use hydraulics to raise and lower the height so passengers can board easily. Airplanes use them to control the flaps and to raise and lower the wheels. Cranes and forklifts are used to lift and move heavy objects.
Here are two examples of hydraulics in use. Top left: a pallet jack has a bottle type hydraulic jack that uses the white lever to fill the bottle with compressed air which raises the forks. It can lift more than 3,000 pounds. Top-right: a forklift is used to elevate Tim to change the lightbulbs. Here, a propane engine creates the force needed to lift loads as large as 5,500 pounds. It uses a counter balance so it doesn't tip over. Bottom: This forklift runs on diesel power. It is capable of lifting several tons.
Photos taken at Spenard Builders Supply in Fairbanks, Alaska.
For a video of hydraulics in action, click on the links below.
Forklift lower (16kb)
When the lift was being raised, the engine forced air into the system which made the pressure increase. This caused the pistons to raise.
When the lift was being lowered, a release valve slowly let the air out of the chamber, and the pressure was decreased.
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