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Fluids are continuous, shapeless substances

whose molecules move freely past one another and

have the tendency to assume the shape of its container;

Liquids or Gasses

By itself, fluid has no power,

but when confined and

placed under pressure,

Fluid can transmit power

that can be stored,

directed and made to do work.

Fluid Power Systems

•Amplify Power

•Transmit Power

•Control Power

Fluid power is pressurized liquid or gas in a closed system.

Fluid power can be hydraulic or pneumatic.

Hydraulics use pressurized oil or other liquids.

Pneumatics use pressurized air or other gasses.

Blair Pascal was a scientist who lived in the mid 1600’s. He described how liquids behave. He built a container like this to show that water pressure depends on the depth of the water, not the size or shape of the container.

A B

Pascal Law states that pressure at any point in a body of fluid is the same in every direction, exerting equal force on equal areas. Now if you apply more pressure to one side of the container, the fluid will rise on the other side.

You might think that there is more pressure under side B, because there is more water, but if it had more pressure, it would push side A up.

Read “The Basic Idea” from How Stuff Works. Push on the red arrows to see how a simple hydraulic system works and how we can obtain a mechanical advantage by changing the size of the pistons.

http://science.howstuffworks.com/hydraulic1.htm

The force is measured in pounds per square inch. (psi)

Large movement in the smaller piston requires less effort,

but causes the large piston to produce a great amount of force.

A piston is a solid cylinder or disk that fits snugly into a larger cylinder and moves under fluid pressure, as in a reciprocating engine, or displaces or compresses fluids, as in pumps and compressors.

Fluid Power Applications

Robotics Wave Pool Jaws of Life Cranes

Log Splitters Jack Hammers

Auto Lifts Automatic Doors

Auto Brakes

On a 1929 Dodge truck

Hospital Beds

Dump Truck Theme Parks Check out the factory

tour!

Animatronics Factories Injection Molders

Nail Guns