By definition, actuators either move things or stop them. In industrial design and other heavy-duty applications, actuators — or cylinders — provide the driving force that moves (or holds) machinery components. You may ask, "Should I choose pneumatic cylinders for my design or some other type? Well, that depends on what you need to move, in what way, and under what conditions.
Pneumatic cylinders are powered by compressed air. But cylinders can also be powered by pressurized fluid (hydraulic), by electricity, or by hand (mechanical). For obvious practicality reasons, we can rule out hand-cranked cylinders for industrial applications.
That Leaves Three Options
There are distinct differences among pneumatic, hydraulic, and electrical cylinders. Nonetheless, identifying which is the best choice isn’t necessarily straightforward. There are a lot of variables to consider. Things like load type, speed, frequency, torque, precision and holding power required, and the working environment.
If you need help exploring your options, here’s an overview of each cylinder type.
These are compact in size and quiet to operate. The actuation process is somewhat more complex than of pneumatic or hydraulic cylinders because the electric motor has to mechanically turn a screw that operates the cylinder. That means it has to be physically part of the actuator, and you’ll need more space to accommodate that. However, thanks to the controllability of electricity, these cylinders can exert highly precise, infinitely scalable movement control. They can also be electronically programmed.
Electrical cylinders cost more up front but can be very affordable to operate. They also pose no environmental threats because there are no fluids to leak. In general, though, they are best suited for projects that require only a few cylinders.
Hydraulics can give you the greatest power and torque, making them a good choice where brute force is required. These cylinders can deliver 25 times the force of same-size pneumatic cylinders. They can also offer a higher horsepower-to-weight ratio. However, there are more moving parts to any hydraulic system, so more maintenance opportunities and cost. And they do leak, which would be a deal-killer in applications where sanitation is crucial.
Many industrial settings use air compressors for a variety of purposes, so supplying air to actuate cylinders is comparatively easy. These are the most versatile workhorses among actuators, a good choice for a wide variety of movements where high torque, precise linear movements, and/or no-fail holding power are required, even at high speeds.
Pneumatic cylinders are tough enough to withstand harsh environments where water or extreme temperatures could present problems for other types of cylinders. And they come in a multitude of sizes, styles, and configurations.
Whether you choose pneumatic cylinders or another type, it is critical that you make the right decision during the design process. Once the equipment is in place, it will be expensive to change your mind. So, are you ready for that consultation phone call? We’re here to help.