While some form of hydraulic system has been in use from early history, it wasn’t until the mid-sixteenth century that the formula was fully understood. Even then, up until the invention of the pump in the nineteenth century, hydraulics had to rely on gravity or a system of weights in order to work. With the invention and development of the pump, the use of hydraulics really took off and it is one of the drivers of our modern industrial age. Some of the heaviest machinery today is powered by hydraulics, with examples including lifts, the control surfaces and landing gear on aircraft, and much more besides.
How does it work?
To put it simply, if you imagine a pipe filled with liquid, at one end is a piston, while the opposite end has a narrow exit. As the piston moves, it pushes the liquid through the narrow exit. Liquids cannot be compressed, unlike solids, so they will always occupy the same volume. The hydraulic liquid is forced through the narrow end with great pressure. Hydraulics is the harnessing of this pressure, using it to lift great weights or to exert great force see for an illustration.
Of course, a sophisticated, modern hydraulic system is rather more complicated than that, comprising many parts. There will be a reservoir to take excess fluid and myriad seals to keep air and dirt out of the system. Then there is the pump, which is often powered by an electric motor and generally connected through a system of belts and gears. The pump supplies the pressurised fluid where it is needed in the system, and this is subsequently controlled by the control valves. An accumulator may be present, which stores energy and, in some systems, can provide a backup braking system too.
Finally, there are the various connecting hoses and the fluid itself. The type of fluid used will vary depending on the machine and the application and may be anything from a fire-resistant fluid to simply plain water and edible oils in machines used for food preparation, to avoid contamination. To further understand what a hydraulic power pack can do and discover the machines available, sites such as www.hydraproducts.co.uk/ have detailed information.
Hydraulics, the practical solution.
The use of increasingly efficient hydraulic systems powers our modern world, spanning industry sectors including automotive, construction, shipping, and all manner of manufacturing and engineering applications.