A Comprehensive Guide to Actuators: What are They, Types of Actuators, and How They Work
Often the essential elements of a device or system are not the showstoppers. They are not the outward beauty of the design or the case. They are not the function that often gets praised. Most of the time, the essential elements of a device are hidden away behind a more aesthetically pleasing shell.
Actuators are a perfect example of this hidden system because they are a necessary piece for a wide range of systems, rarely getting any credit for their incredible actions. So, in this article, we’ll go over what actuators are, how actuators work, the types of actuators, and how you can choose the right actuator for your project.
A machine's actuator is the part in charge of moving and controlling a mechanism or system, for opening a valve. It is a "mover," to put it simply.
Actuators require both a control mechanism and an energy supply. Typically, the control device is a valve. The valve requires a low-energy signal to activate. It can be activated with electrical voltage, pneumatic or hydraulic fluid pressure, or even by human force. Electric current, hydraulic pressure, or pneumatic pressure are also potential energy supplies.
They use a piston, motor, or another device to work by converting power from an electric or fluid source. In their most basic form, actuators open or close valves. On the other hand, position regulating or control valves interpret a positioning signal to precisely move to any intermediate position. The control system can be operated manually or automatically, powered by software, mechanically, or electrically.
An actuator enables any machine's ability to generate motion. Essentially, actuators act as a motor that transforms energy into torque and uses that torque to move or regulate a mechanism or system. They can both cause and stop motion.
How Does an Actuator Work?
The actuator is the portion of a mechanical apparatus that enables movement, just as muscles in the human body enable legs, arms, fingers, and other body parts to move. It enables movement by transforming incoming energy and signals into a mechanical force. While the outgoing motion can be either rotational or linear, the centering force can be electric, pneumatic (air), or hydraulic (water). Thus, actuators are all around us, from access control systems on our doors to the nearby warehouse robots performing the heavy lifting. Even the silent versions of our cell phones include actuators that produce vibrations.
An actuator, as previously mentioned, may assist in converting energy into motion while also assisting in controlling that motion and energy.
The kind of energy, the volume of input, and motion speed are the variables in an actuator system. The identical components that actuators use also have varying visual appearances depending on the kind and function of the actuator.
The Components of an Actuator
Actuators require a few basic components. These components include:
- Power supply: As said, the power source might be electric, air or gas, water, or any energy source, but these are the ones that actuators most frequently use.
- Power converter: Power transfers from the power supply to the actuator through the power converter. This operation follows any measurements or units specified on a controller or in its design.
- Actuator: The actuator, a physical-mechanical device, carries out the conversion. Depending on the input/output you are using and the desired result, it may appear different.
- Mechanical load: The mechanical load is stress or force that opposes the energy the actuator creates in the system. It causes the system to generate more electricity as a result.
- Controller: The controller is a device that turns on the actuator and manages the output, directing its force, lifespan, and direction. In addition to preventing the system from operating independently, it permits restrictions at both ends of the conversion that the operator may control.
Types of Actuators and How They are Used
There are seven basic types of actuators all with unique purposes.
Electric linear actuators are generally employed in automation applications when a machine part or tool needs a controlled linear movement to a certain point. When linear positioning is required, they get utilized across various sectors.
Electric rotary actuators are employed in automation applications when a gate, valve, and other similar parts are controllable to move to specific rotating locations. Additionally, they get used in various sectors where positioning is necessary.
Fluid Power Linear
When an object needs to be moved carefully to a particular position, fluid power linear actuators typically get utilized in automation applications. When linear positioning is required, they get used across various sectors. The opening and shutting of damper doors, clamping, welding, etc., are typical uses.
Fluid Power Rotary
When an object needs to get rotated in a controlled manner to a particular position, fluid power rotary actuators are used. The most common use of a fluid power rotary actuator is automation applications. Air or other gasses and hydraulic fluid are some of the different media that powers the actuator.
Linear Chain Actuators
The linear chain actuator generally provides a straight line push or pull action in motion control applications. When the chain is straight, neighboring links lock into place to create a stiff component. Depending on the area available in a specific application, they come in a variety of sizes and chain designs, as well as chain storage choices.
Most commercial applications for precise positionings, such as manipulating tools or workpieces, employ manual linear actuators. Unpowered manual actuators get turned on and off by turning a handwheel or knob. There are many different kinds, each with an additional load and driving force capacity, such as those with lead screws, racks, pinions, belt drives, etc.
Valve operation is the primary usage of manual rotary actuators. They sometimes get referred to as manual valve operators or actuators. Ball, butterfly, check, and globe valves are a few different types. Other uses may include anything that calls for controlled and constrained rotation.
8 Steps to Choose the Right Actuator for Your Application
Naturally, various actuators get used in multiple industries, and not everyone will be appropriate for your needs. Here is a brief guide to choosing the best.
Determine the Type of Movement Needed
You'll be able to see if the function calls for decisive linear motions or if additional dynamism is needed in the final function, depending on the function. But you might also want to think about how far you want that movement to go.
Considerations for Energy Input
Electrical actuators are widely used and can perform a more comprehensive range of tasks. However, in cases where the required electrical current is not always feasible, you can use hydraulic and pneumatic actuators to do away with the requirement for high voltage input.
According to a "general" rule, smaller, more detailed, and delicate jobs, including selecting and handling, need more accuracy. In contrast, heavy-duty labor may get by without it. That factor will substantially influence the actuator you choose.
What Force is Best
The main goal of an actuator is to move anything; however, the amount of force needed varies according to how heavy or oversized the item is. Consider the sizes of the things your actuator needs to move when selecting one with a sufficient load capacity.
How Much Room is There for Movement?
Any actuator will have a stroke length, which you should consider when selecting one for your intended use.
What Speed Are You Looking For?
The speed of the actuator is a significant factor because actuators requiring more force are frequently slower than those generating less force.
What is the Operational Environment?
Both industrial applications and the more structured settings of interior labs and workshops regularly utilize actuators.
How Will it be Mounted?
There are several mounting options for actuators. A dual-pivot mounting mechanism, for instance, enables the item to rotate or swivel while extending and retracting. The actuator is kept in position more securely with a fixed mounting mechanism.
How to Mount an Actuator
There are two primary methods of mounting an actuator; Dual Pivot Mounting and Stationary Mounting:
Dual Pivot Mounting
An actuator is mounted on a pivoting platform using mounting pins or clevises attached to each bracket on either end of the actuator. These are mounting brackets because a cross pin connects the actuator and bracket by sliding through both. The actuator can swivel around each pin, shifting along with the thing it is moving and enabling a more dynamic function.
The actuator may generate push or pull motions from a fixed location with stationary installation, which entails fastening the actuator to a shaft mounting bracket. For example, this is how a button gets installed.
Real-World Applications of Actuators
An actuator is optimal for a specific application if it can provide enough force, has adequate load-speed characteristics, operates with high efficiency within the operating range, and has a reliable design.
Industrial automation and robotics are the two industries where it is impossible to envision doing anything without actuators. These components allow production machines to move about and pick up items. Actuators are frequently employed in agricultural and large construction machines to permit a variety of motions. Solar panels are a stunning example of how actuators may get used. The solar panels with actuators continuously adjust their angle throughout the day as the sun rises and sets to capture the most solar energy.
Actuators are a common component of nearly every smart home appliance, from furniture to robotic vacuum cleaners that need to move in any direction. Many toys even have a few tiny actuators integrated right into them. The possibilities are limitless.
Nearly all modern household and industrial devices use actuators. However, developments in the field receive minimal media attention compared to leading-edge technologies like Artificial Intelligence (AI), Blockchain, Internet of Things (IoT), 3D printing, and more.
New actuators with improved performance characteristics will get conceptualized during the next couple of years, and those that are now getting researched will enter the market.