How Do Hydraulics Work?

The working of hydraulic machines is based on the simple principle of transferring mechanical energy from one point to other with incompressible fluids as the medium. Here's more...
In today's world, we can see that many of the machines used for industrial purposes make use of hydraulics. The use of hydraulics has streamlined the working of heavy machines. Arduous tasks such as lifting (cranes), stone crushing (diggers), etc. have become easier.
Hydraulics is a subject in engineering which deals with the study of the mechanical properties of fluids. Pressurized liquids are used in the generation of power, its control, and its transmission. Various concepts, such as fluidics, dam design, pipe flow, and fluid control circuitry are studied in hydraulics.
Working of Hydraulics
The idea behind the working of hydraulics is very simple. Mechanical force applied at one point is carried to the desired point by means of an incompressible fluid. Different types of hydraulic motors and cylinders make use of this fluid power in the functioning of machines. Tubes and hoses direct the flow of fluids while control valves regulate their flow. One may find several applications of hydraulics in the form of car brakes, garage jacks, motorboat steering, cranes, and garbage trucks among others.
To understand why fluids hold so much importance in the functioning of hydraulic machinery, let us try to understand the concept of hydraulics with the help of a water pistol. In a water pistol, the spout or opening, through which the water squirts, is narrow, while the place at which force is applied (trigger) is comparatively wider. When our finger applies force by means of the trigger, water is pushed towards the narrow spout. Since fluids are incompressible, the resulting speed with which water comes out of the opening is greater as compared to the speed with which trigger is pressed.
In different machines that work on the principle of hydraulics, the course of action which takes place is exactly opposite/reverse to what is illustrated in the above example. Now, imagine that water is forced through a narrow spout at high speed, the force generated at the other (wider) end would be sufficient enough to carry out a mechanical action. Big machines like cranes, diggers, etc., make use of fluid tubes and rams. The drivers of these vehicles operate the process of forcing in fluids through narrow tubes; which in turn push the rams into action. The functioning of hydraulic machines is based on this simple concept. It helps us in understanding how hydraulics are used, and the methodology behind various applications in industrial hydraulics.
Hydraulic Engineering
It is one of the branches of construction engineering which deals with conveyance of liquids; primarily water. The activity of designing dams, bridges, canals, channels, levees, etc., comes under this branch of engineering. Maintenance of aqueducts, an activity which comes under the purview of hydraulic engineering was carried out during the Roman Empire. The science of hydraulic engineering is related to geotechnical and transportation engineering, since hydraulic engineers have to construct water collection networks, water distribution networks, undertake storm water management, and also deal with sediment transportation.
Pneumatics and Hydraulics
The main difference between hydraulics and pneumatics is that liquids are used in the former, while the later makes use of gases in its various applications. Gases can be compressed, while fluids are incompressible. The working pressure in hydraulics is much greater in comparison to that in pneumatics.
The above article helps us in understanding how hydraulics work through easy to understand examples and some basic information related to the core concept.