Creating Lasting Repairs

What Are Hydraulics?

by Marvin Gilbert

Hydraulics are used in just about everywhere in the world. They are a pretty simple machine and can be used in a variety of areas. 


Hydraulics take advantage of the pressure that can be created by liquids. In the past, it was water, but these days it can be special liquids, oil, water, or just about any other kind of liquid that works. The oil and hydraulic fluids tend to be used more than water these days because the fluids can be adjusted and engineered to be exactly what is needed. They can be denser than water, as well as slipperier, which can be useful in certain situations. 

How They Work

Hydraulics are actually pretty simple. They consist of reservoirs, tubing, and some kind of valve. When the liquid is released from the reservoir and out into the tubing, then it causes something to happen. When the valve is opened again and the liquid drains out, then the opposite action occurs. For example, look at the hydraulic cylinder that is on doors all over the place. When you open the door, a valve opens and the fluid pushes the cylinder open. When the door closes, the valve opens again and the fluid goes back into the reservoir and the cylinder starts to close again, allowing the door to shut. All hydraulics systems work in the same way, just some systems are much more complicated than others. 

Control Valves 

One of the things that is necessary to the more complicated systems is a series of control valves. These valves will control a series of smaller valves which will activate different parts of the system. For example, on a large tractor, the operator may have a board of switches and levers in front of them. As they pull one lever, the action triggers one valve to open. That valve opening causes other valves to either open or close. Then the action that the lever controls will happen. If the lever is to close a scoop, then pulling the lever will trigger the valve to open up the system that controls the scoop. That will open the reservoirs to either put liquid into the system or take it out so that the two pieces of the scoop close. Then the operator can use another lever to move the scoop. 

Hydraulics have been used for millennia. They are easy to make and easy to operate and can make life so much easier.