Plenty of methods for power transmission find use in industrial settings. One might assume that electrical power sets a gold standard, to the point that other means seem redundant, but this is far from the truth. Mechanical power remains valuable at small scales, with pneumatics being a prime example. Pneumatic power is still a viable and cost-efficient solution to many engineering problems, and a compressed air system is not an uncommon sight in industrial facilities.
Simple and Compact
Compared to electrical systems, fluid power is easier to control and convert to linear motion. Driveshafts, gears and elaborate drive controls are replaced with cylinders, actuators and valves, all of which are simpler to construct and more easily scaled down in size. The power-to-weight ratio favors pneumatics over hydraulics, too: lower pressure means lighter materials can be safely used, and pneumatic ‘plumbing’ can vent exhaust air to the atmosphere instead of having to reroute it to a fluid reservoir. This is what enables, for instance, handheld pneumatic tools.
For scenarios where a precise and quick application of force is more important than delivering high power, pneumatics wins out. Air is easier to move rapidly than hydraulic fluid or heavy electromechanical parts, and many pneumatic systems have relatively low inertia, allowing for rapid changes in acceleration. While the compressor may take time to build up a supply of compressed air, the delivery of power from the air tank is quick. Also, even though the compressor needs to be powered by electricity, no other components need powering, so pneumatics still function during brief outages.
Despite the impression that one may get from an air compressor while it’s running, pneumatic systems circumvent many potential risks of other power systems. Electric motors and components are vulnerable to heat damage, literally burning out if overloaded; a pneumatic motor will merely stall out. Compressed air isn’t flammable, either, unlike hydraulic oil, and the compressibility of gases reduces the risk of damage from excessive pressure.