How Do Hydraulics Work?

Posted on: 11 November 2015

The theory of hydraulics has been around for a long time. Hydraulic systems have been used to build and shape the world for centuries. Part of the reason is that a hydraulics system is really a very simple system. As long as there are two or more cylinders and a noncompressible liquid inside the system, a hydraulic system will work. 

How Does a Hydraulic System Work?

The way that a hydraulic system works is that one piston in a cylinder pushes down onto the hydraulic fluid. Since the fluid doesn't compress, it has to move. It moves along the tubes or pipes connecting the two cylinders. When it gets to the next cylinder, the fluid does the only thing that it can: it pushes the piston back up. All the energy that was expended pushing one piston down is transferred to the other piston. 

Can a Hydraulic System Multiply or Divide Force?

Yes, a hydraulic system can easily multiply or divide the force being expended. If the pistons on each side of the hydraulic system are the exact same size, then the amount of energy the piston getting pushed up receives is the same as was used to push the other cylinder down. The way to magnify the force is to use different-sized pistons. If the cylinder that gets pushed down is smaller in width and area than the cylinder that gets pushed up, then the force is multiplied. For example, if you have a piston that is 3 inches wide getting pushed down and a 12-inch wide cylinder getting pushed up, the area of the larger cylinder is much greater. That means that for every bit of force that gets expended pushing down the piston on one end, a much greater force is applied to the piston on the other end. 

Dividing force works in a similar way. If the area of the cylinder that is reacting to the pressure is smaller, then a smaller amount of force is going to come through at the other end. 

Hydraulic systems are found in everything from the brakes of your car, to the hinges of doors, to the large equipment that builds skyscrapers. Without the simple mechanics that make up those systems and their force multiplication and division capabilities, then it would be much harder to do a lot of things, including stopping your car when necessary. You couldn't exert enough force on your own to stop your car safely, but the hydraulics in your brake system can. For further information about hydraulic systems, contact a representative from a company like Hydraulic Hose & Cylinder Inc.