Actuators are a key part of automation and are used in everyday equipment and industrial machines to convert energy into motion. They do a lot of heavy lifting and, therefore, require frequent maintenance and even replacements to ensure that operations run smoothly.
This makes it important for engineers and electrical technicians to understand the types and choose the right
actuator to ensure reliability and predictability in machines. In this guide, we will look at the main types of actuators and see how they function. We will also look at how to make the right selection.
What is an actuator?An actuator is a device that takes in signals and turns energy into physical movement that can then perform a variety of tasks. Its main job is to automatically create a controlled motion that can then be used to accomplish various tasks, mostly in industrial environments or in heavy machinery.
Actuators vary significantly based on the technology behind them, but they are all required to ensure precise and repeatable motions. For example, they may be required to control the movement of packing machinery at high speed. Or maybe ensure that robotic arms can weld with precision. Actuators can be grouped into different categories:
Pneumatic actuators — these actuators use compressed air to generate motion. And since air is readily available in most factories and can actually be easily controlled, these actuators are quite common and work well in areas that require repetitive motion. Some common uses of pneumatic actuators are controlling valves and robotic arms. They are well-liked for their speed and simplicity, and are safer compared to others that need electrical current.
Electrical actuators — These actuators use motors powered by electricity to create mechanical movement, which can either be linear or rotary. They are quite versatile and can be easily integrated with
control systems, something that makes them quite popular in automated production lines. Some common applications are tasks that require robotic arms. They work well here as their movement is quite accurate, and the actuators can also be adjusted to try and balance between speed and torque.
Mechanical actuators — This type is more manual and relies on simple physical components like gears or levers to create movement. They are a bit simpler than the other types and only need force to be applied, not power. This makes them more reliable and low-maintenance. Mechanical actuators are mostly found in presses, jacks, or basic machine tools that need motion without relying on complex control systems. For example, a screw jack can lift heavy loads with precision. However, it may not offer the speed or flexibility of powered actuators.
Hydraulic actuators — These actuators use pressurised fluid to create movement. They can be used to move extremely heavy loads that can be a bit problematic for electrical or pneumatic actuators. Some common uses for hydraulic actuators are lifting or lowering heavy equipment and operating presses. They are quite reliable, but they need the entire system(pumps, hoses, and valves) to be properly maintained to ensure there are no leaks that can cause loss of pressure when under heavy load.
Choosing the right actuatorTo select the right type of actuator, start by considering how it’ll be used, the environment, and the performance requirements. From there, you can consider the type of motion in terms of load, speed, and precision. The various actuators all have different advantages, something you’ll also need to factor in. For example, electrical actuators will give you a bit more
precision and control, while hydraulics are much better at handling heavy loads.
The environment the actuators will be used in should also play a role. For example, you can expect electrical actuators to be risky and dangerous in harsh environments, but hydraulic and pneumatic actuators won’t have issues there. When you match the actuator with the application, it will be easier to ensure reliable and safe operations.