There are many types of hydraulic machines that include large machinery, such as backhoes and cranes. Other types of smaller equipment include log-splitters and jacks. The brake on a vehicle is another example of a hydraulic system.
An excavator at a construction site is an example of heavy equipment that takes full advantage of hydraulic systems. Not only is the large bucket that can dig up tons of material powered by large hydraulic cylinders, the tracks that move the machine around are also hydraulically powered. The diesel motor on board merely powers a hydraulic pump that moves fluid to slave cylinders.
A skid/loader is another example of heavy equipment that makes use of multiple hydraulic systems. All four wheels are powered by hydraulic motors independently, giving the machine great mobility. Raising and lowering the bucket, rotating the bucket to scoop or dump, and splitting and closing the bucket to grip objects all require separate hydraulic systems.
Hydraulic machines and systems consist of a basic setup where fluid is forced from one cylinder to another. These machines get their strength and efficiency through changing the size of one cylinder compared to the other, a principle called hydraulic multiplication. By trading distance for force, applying force to a piston in a small cylinder pushes fluid through hydraulic lines to a large cylinder, multiplying the end force the large cylinder piston exerts in proportion to the size difference of the two cylinders. The two cylinders are termed the master and slave cylinders.