Definition of hydraulic and pneumatic systems

Definition of hydraulic and pneumatic systems
Machines of all kinds need energy. This allows machines to do certain types of work. Two of the most efficient and compact forms of power for machines are hydraulic and pneumatic systems. These systems can be configured in different types of energy sources to lift, lower, pull, push, turn, rotate and move the machines that carry huge loads. The tools can also be powered by energy to break stone, join steel and cut wood. The hydraulic and pneumatic systems provide the energy needed to make things work.


The hydraulic system works based on the principle of pressurized fluid forcing mechanical action. One of these systems installed in a machine is called a "hydraulic circuit." These circuits are composed of a pump to compress the fluid, lines to carry it, a cylinder where the liquid is pumped and a piston moved by it under pressure in the cylinder. The hydraulic system can also drive shafts for hydraulic motors and conveyor belts.


The pneumatic system is similar to the hydraulic one with an important difference: instead of liquid, it uses gas (usually air). The air is collected in a compressor and then forced through the lines to the different tools. Compressed air drives pistons and trees and forces them to move. The pneumatic system is often used for different types of hand tools and also for machines that perform repetitive movements. A pneumatic hammer is a good example of a repetitive pneumatic tool.


Beyond the difference of liquid and gas, there are other differences between pneumatic and hydraulic systems. Hydraulics are closed circuits: the liquid is sent to the cylinder, moves the piston and then circulates back to the pump. The tires, on the other hand, "breathe" and do not circulate the air. Compressed air is sent to the tool to do the job and then through an exhaust hole. More air is pulled into the compressor when it does more work.

Hydraulic installations

Hydraulic systems are installed to do heavy work in a wide variety of vehicles and production machinery. Pressurized hydraulic fluid can withstand huge loads and relatively small circuits can lift and move many tons of material. This system is also used for stamping, pressing and rolling machines, such as in a steel factory or manufacturing plant. Hydraulic circuits are also used in cars, trucks and airplanes to drive various systems, such as brakes, elevators and control surfaces (flaps).

Pneumatic installations

Pneumatic systems are used in all types of assembly and manufacturing facilities. The source of repetitive pneumatic action is ideal for tools such as drills, hammers and chisels. This system is also installed to move elements in assembly lines and maintenance facilities, such as garages and aircraft hangars.