Electric actuators are crucial components in automation systems widely used in numerous industries. They are vital in the transition to Industry 4.0, as they generate mechanical motion in various applications such as robotics, industrial automation, and electric vehicles.
Suppose you’re interested in learning more about electric actuators. The Bawalaksana team has an informative article that delves into the main components of electric actuators and their functions in producing linear motion.
Electric actuators are particularly suitable for automation systems that require fast and precise motion. However, as discussed in our previous article, electric actuators have advantages and disadvantages that must also be considered.
Understanding the components of electric actuators is crucial for maintaining optimal device performance, particularly in various industrial applications. It’s worth noting that some types of electric actuators may have different component compositions than those mentioned in this article.
To shed more light on this topic, we have summarized the explanation from IQS Directory and Timotion, which highlights the following details:
1. Front / Rear Clevis
One of the essential components of electric actuators is the Front/Rear Clevis (no. 1). It is a U-shaped metal component with holes at each end, used for pins, bolts, or other fastening tools.
Clevis connections at the actuator’s front and rear connect it to the application or other device that needs to be operated and to different parts of the automation system.
Appropriate pins, bolts, or fastening tools are essential to ensure secure attachment.

2. Inner Tube
The Inner Tube (no. 2), also called the extension tube or piston, is a part that extends or acts as a stroke.
In general, the Inner Tube is made of aluminum or stainless steel. Its main function is to support the Spindle when the actuator arm shortens.
On this Tube’s shaft is a Drive Nut with threads. This nut converts the Spindle’s rotational motion into thrust to extend or shorten the Inner Tube.
In other words, when the Spindle rotates inside the Inner Tube, the Inner Tube will automatically extend or shorten because of the Drive Nut, according to the Spindle’s direction of rotation.
From there, the rotational motion of the motor is converted into linear motion.
3. Outer Tube
The Outer Tube (no. 4), also known as the cover tube, is an essential component of a linear actuator.
The outer Tube is made from an extruded aluminum tube with a customized shape. Its function is to protect the linear actuator on the outside and keep all the internal components of the actuator safe and protected.
This cover tube is a physical protector that prevents damage to the actuator’s internal components caused by friction, dust, dirt, or other external contamination.
The Outer Tube is usually made of robust and durable aluminum to provide optimal protection.
In addition to its protective function, the Outer Tube also serves as a container or place to accommodate all the internal components of the actuator, including the motor, gear, Spindle, and others.
In short, the Outer Tube plays a role in maintaining cleanliness and keeping all actuator components well-organized and protected.

4. Wiper Sealing Component
Wiper Sealing (no. 3) is a sealing component located at the end of the outer Tube. Its primary function is safeguarding the actuator spindle area by preventing contaminants such as dust or liquid infiltration.
Proper sealing between the Outer and Inner Tubes is essential. This aspect directly impacts the actuator’s IP (Ingress Protection) level.
Thanks to the inclusion of the Wiper Sealing Component, the actuator spindle is shielded from contaminants. This significantly contributes to maintaining the cleanliness of the actuator components, thereby enabling optimal performance.
5. Drive Nut
The Drive Nut (no. 5) is a crucial component in many industrial actuators that operate using a spindle. Its primary function is to rotate along the Spindle and allow the inner Tube to retract or extend as needed.
The material used to manufacture Drive Nuts can vary depending on the actuator’s requirements, with plastic and metal being the most commonly used materials.
Additionally, some Drive Nuts come equipped with locking mechanisms to prevent unwanted rotation of the Inner Tube, adding an extra layer of safety and stability to the actuator system.

6. Spindle
The Spindle is a crucial component of the actuator device that helps provide longitudinal movement for the Inner Tube. It rotates and transforms the motor’s rotational motion into linear motion, pushing the Inner Tube.
Spindles are typically fabricated using high-quality steel to ensure their strength and durability for extended usage.
They are manufactured with precision to ensure that they fit precisely with other components of the actuator device and function seamlessly.
The surface of the Spindle is often treated to enhance its resistance to wear and tear, corrosion, and other environmental factors that could affect its performance.
7. Safety Stop
The Inner Tube has a Safety Stop at its end, which prevents it from extending excessively when the Spindle rotates and pushes it.
Thanks to the Safety Stop, the linear movement stops automatically when the Inner Tube is pushed too far, ensuring safety and preventing damage to the actuator devices or other equipment.
Maintaining this function is crucial to ensure safety and prevent damage to equipment.
8. Limit Switches
The next one is the Limit Switches, also known as position switches, which play an essential role in controlling the position of the Inner Tube of electric actuator devices.
They act as switches and cut off the electric current to the motor when it reaches a predetermined limit, preventing the actuator arm from extending or retracting excessively.
Limit Switches also function as signal transmission devices, providing information about the position of the Inner Tube.
Therefore, this component is crucial in ensuring the operation of electric actuator devices safely and efficiently.
9. Gears for Electric Actuators
Gears for Electric Actuators (no. 7) are an essential component of the actuator mechanism.
These gears are either plastic or steel, assembled and connected inside the actuator housing. Multiple gears are on the motor shaft, and the rotational energy transmits to the Spindle when the motor rotates.
Consequently, the Spindle pushes the inner Tube, resulting in linear motion. This mechanism allows precise and accurate control over the actuator’s linear movement.
10. Motor Housing
The Motor Housing (no. 8) is a container for the motor and a group of gears, providing a secure attachment to the Outer Tube and Inner Tube with precision.
Motor housing protects the motor and its internal components from dirt and other harmful elements that can cause damage. Therefore, motor housing is made from high-quality plastic that is lightweight, corrosion-resistant, and can safeguard the motor from moisture or harsh environments.
A solid and durable Motor Housing will protect the motor and its internal components well, which can significantly contribute to optimal performance and a longer lifespan of the actuator.

11. DC Motor
DC Motors are a source of motion that converts electrical energy into mechanical energy. There are different types, with the most widely used being brushed motors.
DC motors are made up of various components, which include:
Motor Stator
The Motor Sator is the stationary outer part. The motor housing, caps, and two permanent magnets surround the rotor. In some cases, the permanent magnets can be copper coils supplied with electricity.
Rotor
The rotor is the inner part of the motor that rotates. It consists of the motor shaft, silicon steel laminations, copper coils, and a commutator.
Commutator
The commutator is a set of small copper plates mounted on the motor shaft and connected to the rotor. It conducts electricity from the carbon brushes to the copper coils in the rotor.
Carbon Brushes
This component, also known as carbon brushes, transmits electric current from the stator to the rotor, which experiences friction when the motor rotates.
Motor Shaft
The DC motor shaft connects the rotor to the motor gear. Therefore, when the rotor rotates, it rotates the gear and Spindle.
12. Output/Feedback Sensors
Electric actuators are widely used in various applications that require high-level functionality. However, to enhance their functionality, these actuators must be combined with Output/Feedback Sensors.
These sensors communicate the actuator’s stroke position and provide feedback to the Microcontroller Unit (MCU). They are critical in applications that require advanced functions such as synchronization and memory positioning determination.
With these functions, the actuator can remember its initial position before receiving other commands from the Programmable Logic Controller (PLC). Typical sensor options include the Hall Effect Sensor, Potentiometer (POT), and Reed Sensor.

Hall Effect Sensor
The Hall Effect Sensor can produce a signal based on the density of the magnetic field around it.
Once the magnetic flux density surpasses the predetermined threshold, the sensor detects it and outputs the Hall voltage. These sensors can offer precise position feedback and can be utilized in linear actuators.
Potentiometer (POT) Sensor
The potentiometer sensor comprises a wiper and two end connections that can modify the output of an electrical signal.
By rotating the linear actuator’s spindle, the resistance between the wiper and the two end connections changes, and each resistance value represents a specific position of the actuator stroke.
This resistance value can be used to measure the stroke position. The resulting measurement is then utilized as a metric in the simultaneous application of two actuators.
Consequently, two actuators can be used together to deliver the same accurate stroke position.

Reed Sensor
A magnetic position sensor called a Reed Sensor can operate as an electrical switch. It is responsive to a magnetic field.
This sensor consists of a pair of contacts (axis) on an iron metal stem that is sealed inside a glass envelope.
The pair of contacts will be open in the normal or standby state. However, if there is a nearby magnetic field, they will close, thus closing the circuit. This event functions to disconnect power to the actuator.

How do electric actuators and sensors work?
Electric actuators and sensors work together to control the actuator’s stroke accurately. Output/Feedback Sensors assist the Microcontroller (MCU) in this task.
Electric actuators with feedback sensors become essential in applications requiring synchronization and memory positioning functions.
Synchronization is the ability to move two or more actuators simultaneously at the same speed and position. Memory positioning, on the other hand, allows previously determined positions to be stored and repeated.
Combining electric actuators and sensors with a Programmable Logic Controller (PLC) can automate industrial processes. The PLC can receive input from Output/Feedback Sensors and send output to the actuators.
This allows the actuators’ movements to be controlled by the specified program logic.
Therefore, the Output/Feedback Sensors and PLC can work together to effectively, precisely, automatically, and efficiently achieve synchronization and memory positioning in actuators.

Electric Actuators for Industrial Automation
The development of actuator technology has the potential to inspire numerous innovations in the industrial sector. This rapid and dynamic advancement allows companies to enhance productivity and stay competitive.
However, investing in new technology can present challenges, including workforce skills, infrastructure, and safety regulations.
The good news is that implementing industrial automation using electric actuators is now more accessible, particularly for organizations with professional resources and adequate infrastructure.
We also understand that many manufacturers want to implement automation systems in their companies this year to participate in the ongoing transition to Industry 4.0.
For this reason, Bawalaksana offers you a chance to explore your potential in implementing industrial automation systems.
PT. Bawalaksana Central Industrial is the authorized distributor of Metal Work Italy, offering a wide range of electric actuators for industrial automation systems. Metal Work is a pioneer in advanced pneumatic devices and components and a leader in cutting-edge automation technology.
As an authorized distributor, we can deliver comprehensive solutions for your company, ensuring the seamless implementation of modern, tech-integrated industrial automation systems.
If you have any questions regarding the appropriate utilization of electric actuators for your company, please feel free to speak with our team of Sales Engineers.

Romanta Pinrih Linuwih
Pneumatic Automation Systems Expert
This article was written in collaboration with Romanta Pinrih Linuwih, an expert in Pneumatic Automation Systems, to ensure accuracy and high quality.