Whilst both hydraulic and pneumatic systems feature heavily in day-to-day life, there are fundamental differences between the two systems.
The most obvious difference between the two is the fluid they use to operate their systems. Whilst hydraulics rely on creating energy from pressurised liquid, pneumatics use filtered and pressurised air to make their systems work. Most pneumatics use pressurised air, dry or lubricated.
Other differences include the applications where these systems are utilised. Pneumatics are more commonly used for lower pressure needs, as gas is more compressible than liquid. Pneumatics are primarily used for shock absorption. This is partially because air is easy to compress and works effectively within a pneumatic system to absorb shock. Most of the time, pneumatic systems operate with a pressure of around 100 psi. This is generally quite low but works well for the various applications and tools that use it. Hydraulic systems are better for heavy-duty tasks as they are more robust and operate at higher psi.
Also, hydraulic systems are more costly to install and maintain, due to their complexity. This is mainly because the fluid is contained in a closed system. This differs from pneumatics, as they can draw in air from outside and compress it, then release it when it is no longer needed. This makes them a more sustainable and budget-friendly option. However, some pneumatic systems contain air in a reservoir that’s compressed to a higher degree than the air outside. This makes it more of a closed system, albeit one that’s easier to re-pressurise if necessary.
Pneumatics work on end effectors which could be something as simple as a common cylinder. This is generally one of the first things people think about when it comes to pneumatics. However, it could also be something more complex and specific to different types of applications. For example, it could be air springs, vacuum systems, grippers, and more.