Principle and Components*

Electric Actuators (Linear Actuators)

An electric actuator, also known as a linear actuator, is an electromechanical device that converts the rotary motion of a motor into linear motion.

This transformation is achieved using a screw-nut system (often a trapezoidal screw or a ball screw) coupled with a mechanical transmission (usually a gearbox).

Operating Principle

The electric motor drives the screw in rotation.

Depending on the pitch and type of the screw, the nut — attached to the output rod (piston) — moves in translation, thus causing the extension or retraction movement of the actuator.

Actuators are generally equipped with:

• end-of-stroke sensors, allowing automatic stopping of the movement at the limit,

• and sometimes a position encoder, for precise control and feedback on the rod's position.

Control and Integration

Some actuator models have an integrated controller, which includes:

• power supply (often 12, 24 or 48–51.2 V),

• control and communication interfaces (CAN, PWM or logical inputs/outputs).

This type of actuator is called “intelligent”: it greatly simplifies wiring and integration into an automated system, as it does not require an external controller.

Advantages of Electric Actuators

Electric actuators offer several practical advantages over hydraulic or pneumatic systems:

• High positional accuracy, thanks to the screw and control electronics.

• Cleanliness: no fluid or risk of leakage.

• Reduced maintenance: no seals, pumps, or hoses to maintain.

• Easy control from an electronic controller or standard communication interface.

• High energy efficiency: the energy consumed corresponds only to the work done.

Usage Limitations

Despite their strengths, electric actuators have certain limitations:

• Limited instantaneous power, related to the motor size and available torque.

• Travel speed generally lower than that of pneumatic actuators.

• Maximum axial load must be respected to avoid deformation or premature wear of the screw.

• Lateral forces should be avoided: movement guidance must be provided by the structure, not by the actuator itself.

In Summary

*: The technical information presented in this article is provided for guidance only. It does not replace the official manuals of the manufacturers. Before any installation, handling, or use, please consult the product documentation and adhere to safety instructions. Torque.works cannot be held responsible for inappropriate use or incorrect interpretation of the information provided.