What Are They? Types, Principles, and Applications – Partstack (2024)

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Introduction

Actuators connect the virtual and physical domains of a system. These devices receive some form of energy as input and deliver motion as output. A controlling signal might also be there to allow energy conversion in a controlled way. There are various kinds of actuators available that are categorized on the basis of input energy as well as the type of motion they generate. They are everywhere, from simple household valves to complex autonomous machines used in manufacturing. Many things we rely on in everyday life couldn’t function without these devices. In this blog, we will explore different types of actuators, their working, and a few applications to understand them completely.

What is an Actuator?

In order to generate movement, a system needs actuators, which transform the energy signals that enter the structure into motion. Both rotational and linear movement can be produced through them. Moreover, energy received by an actuator could be in the form of steam, temperature, magnetic force, air pressure, and so on. So, it can be said that the purpose of this device is to transmit motion from an outside source of energy. These devices must not be confused with sensors as their working and purpose differ. Sensors convert physical signals (picked from the environment) into electrical signals, and actuators do nearly the opposite task. They convert electrical or other signals into physical activity.

What do Actuators do?

As explained earlier, actuators produce motion. This motion is controlled, and the extent of this motion depends on the strength of the input energy signal. An actuator control system is attached to the system to regulate the motion and produce accurate movement for various applications. These device controllers process the received signal, convert it into the desired form, and can also manipulate their strength based on the application. Gears, screw jacks, motors, and other mechanical devices are also used in actuator-based systems to enable appropriate working.

Different Types of Actuators: Working Principles & Applications:

There are multiple types of actuators designed to fulfill certain functions. The working mechanism of each of them differs slightly from the other one because the input and/or output type might differ.

On the input side, the power source of these devices could be heat, pressure, or some other physical phenomenon. Likewise, this energy could be transmitted through pneumatic, hydraulic, magnetic, or thermal mechanisms. At the output end, a motion could be linear or rotary. So, here, we will discuss a few common types and their working principles.

Hydraulic Actuator

Hydraulic actuators are the ones that utilize the energy contained by fluids in the form of pressure to generate motion or mechanical energy. They contain piston and cylindrical tube assemblies to generate motion, either linear, oscillatory, or rotary. These devices are very robust and capable of withstanding harsh weather conditions. They are also good shock absorbers.

Hydraulics are mostly used in applications where high force is needed, like opening or closing damper doors, excavators, cranes, and even large-sized walking robots.

Pneumatic Actuator

Pneumatic actuators generate linear or rotary movement by means of a piston, which is moved by pressurized gas or air within a cylindrical container. The gas/air is generated by a pump that exerts high pressure. An air compressor is employed to pressurize a container of air or neutral gas. The rotating piston of the actuator is made to slip in and out by means of this high-pressure air. A basic pneumatic actuator produces linear motion, but some mechanical devices can be attached to convert linear motion into rotary motion.

Pneumatic and hydraulic actuators are quite similar. Their major difference lies in the type of fluid they have. Pneumatic ones have gas or air as fluid, while the latter has some liquid as transmitting fluid.

Solenoid Actuator

Solenoids can be regarded as electrical gates that, when activated, generate an electromagnetic field. That magnetic force in solenoids can cause some mechanical movement or lead to the closing of some electrical points, which would, in turn, activate some electro-mechanical device like a motor. Generally, a solenoid actuator’s output force is directly proportional to the strength of the applied magnetic field.

These solenoids can be used in the packaging industry, fuel injectors, etc.

Piezo/Piezoelectric Actuator

To monitor the application of force or pressure thoroughly, piezoelectric actuators, which have very high sensitivity and, thus, precision levels, are used. These are made of ceramic material like Quartz or ZincBlende. This effect occurs when particular elements undergo a little change in structure in response to an electrical charge. Because of its high brittleness and the fact that it is a ceramic, piezo material is typically stacked with steel plates in between each layer to generate electrical current.

They are used in applications where fine-tuning of lenses, machining tools, etc., is needed. They are also used in the medical sector to conduct surgeries.

Electromechanical(EM) Actuator

Electromechanical or mechanical actuators are electricity-based actuators. In other words, they convert electrical energy into mechanical energy. Linear EM is used in conjunction with electric motors to obtain controlled rotary motion as well. As motor controllers have become very advanced with complex vector control strategies, EM has become very precise and thus more useful.

For decades, hydraulic and pneumatic have been used in almost all applications, ranging from aircraft to industry. Recently, electromechanical actuators have replaced them mostly because of their low maintenance needs, higher precision, and reliability.

How to Select a Perfect Actuator for Your Application

When choosing the most suitable option for your application, it is essential to consider the following elements:

• The actuator’s pace needs to be in sync with the application’s performance requirements.
• To shift the burden and improve systemic resistance, the actuator must be capable of producing sufficient pulling force.
• It is important that it has a stroke duration that is compatible with the application under consideration.
• The desired atmosphere is critical for the actuator’s operation. Therefore, it is important to consider elements like moisture, temperature, and debris or additional pollutants.
• Take notice of factors such as precision, consistency, and backlash when determining the suitability of the actuator for your application.

Conclusion

Actuators are the mechanisms by which an object gains motion. To put it simply, they are essential for the conversion of energy signals into movements for an extensive range of daily gadgets. There are many distinct kinds of actuators, each with its own unique function; for example, piezo, solenoid, and pneumatic. To ensure an actuator is suitable for the task at hand, we must consider its rate of motion, pulling power, noise level, and other relevant factors. Linear actuators are especially eco-friendly because of their simplicity, low maintenance requirements, and exclusive usage of power. Actuators, which ensure that machines function properly and efficiently, are crucial to our daily lives. Even though they don’t seem to be doing anything, they are actually making a lot of progress on a number of different entities.