A linear actuator is a device that generates motion in a straight line to move, lift, position, push or adjust a load. When this movement is produced by an electric motor, it is known as an electric linear actuator, a solution widely used in industrial equipment, medical devices, laboratory systems and many OEM applications.
This guide explains how an electric linear actuator works, its main components and the key parameters to consider when selecting the most suitable actuator according to force, speed, stroke, duty cycle, environment and control requirements.
An electric linear actuator converts electrical energy into mechanical linear motion. It typically uses an electric motor to generate rotary motion and a transmission system, such as a spindle and nut, to convert that rotation into the linear displacement of a rod or moving element.
The main advantages of electric linear actuators include:
One of the main advantages of electric linear actuators is their adaptability. Parameters such as force, speed, stroke, retracted length, supply voltage, control systems, connectors and mounting options can be configured to simplify integration into the final equipment.
For this reason, electric linear actuators are used in a wide range of applications, including industrial machinery, medical equipment, laboratory and analytical systems, special vehicles and OEM products that require precise and repeatable linear motion.
In an electric linear actuator, the motor generates rotary motion that is transmitted to a spindle. As the spindle rotates, a nut travels along its axis and converts the rotational movement into linear displacement. This movement is transferred to the rod or moving element of the actuator, which then pushes, pulls, lifts or positions the load.
To ensure that the actuators can be used in different mounting configurations, rods can be fitted with different types of ends, including mounting holes, clevises, threaded ends and T slots.
Actuators can also incorporate overcurrent protection systems. These systems interrupt the power supply if the actuator becomes obstructed or subjected to an excessive load. Robust housings and seals can protect the internal components against dust and water.
Connectors, cable lengths and mounting brackets can be customised according to the requirements of each application.
One of the main characteristics of a linear actuator is the position of its motor. The motor can be mounted perpendicular to the lead screw axis, using an additional transmission stage, or aligned with the lead screw axis. Actuators with the second configuration are known as inline actuators.
The inline configuration reduces the overall dimensions of the actuator and is particularly suitable for installations where space is limited or where a more streamlined design is required.
Choosing a linear actuator should not be based only on maximum force or stroke. The correct selection requires considering the complete operating profile, including load, speed, stroke, duty cycle, available space, power supply, environmental conditions and control requirements.
Defining these parameters accurately helps avoid unnecessary oversizing, improves system reliability and makes it easier to integrate the actuator into the final equipment.
| PARAMETER | WHAT TO DEFINE | WHY IT MATTERS |
| Force | Actual load and forces acting on the system | Determines the required actuator capacity |
| Speed | Required linear travel speed | Influences movement time and mechanical power requirements |
| Stroke | Total travel distance | Defines the required movement range and affects actuator dimensions |
| Retracted length | Available space between mounting points | Helps determine whether the actuator fits within the equipment |
| Power supply | Voltage, nominal current and starting current | Allows the power supply to be correctly sized |
| Duty cycle | Operating time and movement frequency | Helps manage temperature, performance and service life |
| Environment | Dust, water, temperature, chemicals and cleaning conditions | Determines the required protection level and material selection |
| Control | Position feedback, sensors, limit switches and control requirements | Defines how the movement is monitored and controlled |
| Integration | Connectors, cables, mounting points and available geometry | Facilitates integration of the actuator into the final product |
| Specific requirements | Noise, precision, repeatability, expected service life and regulatory requirements | Ensures the actuator is adapted to the real operating conditions of the application |
What is a linear actuator?
A linear actuator is a device that generates movement in a straight line to move, lift, push, pull or position a load. Electric linear actuators use a motor and a transmission system to convert rotary motion into linear motion.
How does an electric linear actuator work?
An electric motor rotates a spindle, causing a nut to move along its axis. This converts rotary motion into linear displacement, which is transferred to the actuator rod or moving element.
What information is needed to choose a linear actuator?
The main parameters are force, speed, stroke, duty cycle, available space, power supply, environmental conditions and control requirements.
Can a linear actuator be customised?
Yes. Depending on the application, force, stroke, speed, mounting, connectors, cables, feedback systems and other mechanical or electrical characteristics can be adapted to the equipment.
