The Ultimate Guide to Linear Actuators: How They Work, Types, Applications, and Selection Tips

TL;DR: A linear actuator converts rotary motion into straight-line movement. It’s a key component in everything from industrial machinery and robotics to home automation and vehicles. This guide covers how linear actuators work, the different types (electric, hydraulic, pneumatic, piezoelectric, and more), how to choose one for your project, and how to install and maintain them for optimal performance.

What Is a Linear Actuator?

A linear actuator is a device that creates motion in a straight line. While electric motors produce rotary (circular) motion, linear actuators convert that into linear displacement—pushing, pulling, lifting, lowering, or adjusting something along a single axis. This makes them essential for applications that require controlled movement, positioning, or force.

From industrial assembly lines and robotics to adjustable desks, smart furniture, and hidden lifts, linear actuators bring automation and precision into mechanical systems across nearly every field.

How a Linear Actuator Works

All linear actuators share one goal: to turn energy into linear motion. How they achieve that depends on their mechanism and energy source.

1. The Core Principle

Most electric linear actuators use a lead screw or ball screw connected to a DC motor. When the motor turns, the screw rotates, and the nut on the screw translates this rotary motion into linear motion. Reversing the polarity of the motor reverses the direction of movement.

Other types—hydraulic and pneumatic—use pressurized fluid or air to create movement instead of mechanical rotation.

2. The Main Components

Electric motor: Provides the rotary power (typically 12V, 24V, or 36V DC).
Gearbox: Reduces motor speed and increases torque for higher force output.
Lead or ball screw: Converts rotary motion to linear motion.
Drive nut: Travels along the screw to extend or retract the actuator.
Housing: Protects internal components and provides mounting structure.
Limit switches: Automatically stop travel at full extension or retraction.
Feedback sensors (optional): Provide positional data (Hall effect, potentiometer, or optical sensors).

Tip: For a visual explanation, see FIRGELLI’s How Linear Actuators Work page or our Linear Actuator Hatch Calculator for geometry and force calculations.

Types of Linear Actuators

There are many types of linear actuators, each designed for specific power sources, environments, or performance requirements. The main categories include:

1. Electric Linear Actuators

These are the most common type and the core of FIRGELLI’s product line. They use an electric motor to drive a lead screw or ball screw. They offer precise control, clean operation, and easy integration with electronics and sensors.

Voltage: 12V, 24V, or 36V DC (sometimes AC for industrial units)
Force: From 15 lbs to over 2,200 lbs
Speed: Typically 0.2" to 3" per second
Duty cycle: 10–25% standard, up to continuous for premium models

Advantages: Clean, efficient, programmable, easy to install.
Limitations: Force limited by motor torque; not ideal for extremely heavy industrial loads.

2. Hydraulic Actuators

Use pressurized fluid to generate movement. They provide very high force output and are ideal for heavy machinery, automotive, and aerospace applications.

Advantages: Exceptional power-to-size ratio, smooth motion.
Limitations: Require pumps, valves, and fluid maintenance; prone to leaks; not ideal for clean environments.

3. Pneumatic Actuators

Use compressed air to move a piston in a cylinder. Common in industrial automation where air systems are already present.

Advantages: Fast, inexpensive, simple design.
Limitations: Require constant air supply, lower precision, and less holding force.

4. Piezoelectric Actuators

Use crystalline materials that change shape when voltage is applied. Used in nanotechnology, optics, and precision instruments.

Advantages: Extremely accurate, fast response.
Limitations: Very small travel distances, high cost.

5. Magnetic Linear Actuators (Linear Motors)

Operate like unrolled electric motors—using magnetic fields to create direct linear motion without mechanical transmission.

Advantages: Frictionless, high-speed, precise.
Limitations: Expensive, require sophisticated control electronics.

6. Manual and Screw-Drive Actuators

These use a hand wheel, knob, or crank to move a lead screw manually. Common in lab equipment, clamps, and precision fixtures.

Comparing Actuator Types

Type	Power Source	Force Range	Speed	Control Precision	Maintenance
Electric	DC/AC Motor	15–2200 lbs	Moderate	High	Low
Hydraulic	Pressurized Fluid	Up to 50,000 lbs	Moderate	Medium	High
Pneumatic	Compressed Air	Up to 1,000 lbs	Fast	Low	Medium
Piezoelectric	Electric Field	Low	Very Fast	Very High	Low
Magnetic Linear Motor	Electromagnetic Field	Medium	Very Fast	High	Low

Key Performance Parameters

Stroke Length: The total travel distance (e.g., 1"–30"+).
Force: The pushing/pulling capability measured in lbs or N.
Speed: The rate of extension/retraction, usually in inches per second.
Duty Cycle: The ratio of “on” time vs “off” time; important for longevity.
Current Draw: Determines required power supply and wiring size.
Noise Level: Typically 40–60 dB for quality electric models.
IP Rating: Indicates resistance to dust and moisture (e.g., IP54, IP66).
Feedback Type: Determines compatibility with controllers for position sensing.

Applications of Linear Actuators

Linear actuators appear everywhere—from factories to furniture. Here are major sectors:

1. Industrial Automation

Used for positioning, clamping, sorting, and robotic movement. Precision and repeatability are crucial. Electric actuators dominate due to clean operation and control integration.

2. Automotive and Marine

Control hatches, seats, spoilers, engine covers, and marine lids. Compact size and weatherproofing make electric actuators ideal for vehicles and boats.

3. Home and Office Automation

From adjustable desks and smart beds to TV lifts and hidden compartments, actuators bring automation to everyday life. See our list of 25 actuator-based home automation ideas.

4. Aerospace and Defense

Used in flaps, landing gear, and weapon control systems. Precision and reliability under extreme conditions are key.

5. Medical and Laboratory Equipment

Hospital beds, dental chairs, imaging systems—all rely on actuators for controlled, hygienic movement.

6. Renewable Energy

Used in solar tracking systems and wind turbine adjustments for optimizing efficiency.

How to Choose the Right Linear Actuator

Selecting an actuator requires matching force, stroke, speed, voltage, and geometry to your application.

Step-by-Step Selection Guide

Define the motion: Distance to move, direction, and speed.
Calculate the force: Consider load weight, angle, and friction. Use the FIRGELLI Hatch Calculator.
Choose the stroke length: How far must the actuator move?
Select the voltage: 12V DC is most common for mobile use; 24V for industrial systems.
Consider duty cycle: Choose an actuator rated for the frequency of operation.
Check mounting options: Ensure MB1, MB2, or custom brackets fit your design.
Add feedback (optional): For precise position control, choose Hall sensor or potentiometer-equipped models.

Installation Tips

Always mount so the actuator is axially aligned to the load—avoid side loading.
Use pivoting brackets (e.g., FIRGELLI MB1 or MB2) to accommodate angular changes during travel.
Ensure adequate power supply and fuse protection.
Observe polarity for direction control.
Test fully extended/retracted positions before load testing.

Maintenance and Troubleshooting

Keep actuators clean—dirt can cause binding or seal wear.
Inspect mounting points regularly for loosening or misalignment.
Avoid exceeding duty cycle to prevent overheating.
Lubricate lead screw if accessible, using light machine grease.
Listen for noise changes—they often indicate bearing or gearbox wear.

Common Causes of Failure

Overloading beyond rated force
Side loading or angular misalignment
Excessive duty cycle or heat buildup
Electrical overvoltage or reversed polarity
Contamination or corrosion

Industry Standards and Ratings

Linear actuators are governed by several standards and metrics:

IP Rating: Dust and water resistance (e.g., IP54 = splash-proof; IP66 = fully waterproof).
ISO 9001 / CE / RoHS: Manufacturing and material compliance standards.
Load and safety testing: Typically 25% above rated load for safety margin.

Future Trends in Linear Actuators

Smart actuators with integrated sensors and IoT connectivity.
Brushless DC motors for longer life and higher duty cycles.
Self-locking mechanisms eliminating power draw at rest.
Lightweight materials (carbon fiber, composites).
Energy-efficient designs reducing current draw.

Conclusion

Linear actuators are the hidden force behind modern automation—transforming energy into precision motion. Whether you’re building a robotic arm, automating a hatch, or designing smart furniture, understanding how actuators work helps you choose the right one for performance, reliability, and cost.

For more information, explore:

Written by FIRGELLI Automations — pioneers of electric linear motion systems since 2002.

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The 2026 Ultimate Guide to Linear Actuators: How They Work, Types, Applications, and Selection Tips