What are Linear Actuators and Where They are Used?

First of all let us understand what an actuator means. A mechanical device used to move/transfer objects or systems is called an actuator. These actuators can be operated using hydraulic pressure, pneumatic pressure or simple electric current. This energy is converted into motion or movement.

So, What Are Linear Actuators?

In simple words, an actuator that generates linear motion or movement is called linear actuator. Most of these actuators are operated using hydraulic or mechanical actuation techniques and they are using non-linear motion as their input.

Different types of Linear Actuators

Few basic types of linear actuators are listed below. More types can be found out from your suppliers.

Mechanical actuators

In this type of linear actuators conversion of rotary motion into linear motion is done via simple mechanisims. Few of them are given below.

• Screw


• Wheel and axle


• Cam:

Hydraulic actuators

They generally have a hollow cylinder with a piston inserted in it. Piston is pressurized or de-pressurized accordingly on two sides of the piston. In turn the object connected to the piston is also pressurized accordingly. This is a simple hydraulics principle. The displacement/movement happens only at the axis of the piston.A more common example is of a car jack.

Pneumatic actuators

In pneumatic actuators, compressed gas is used to provide pressure instead of a liquid.

Piezoelectric actuators

As we all know, the piezoelectric effect is a phenomenon of certain materials which expand when voltage is applied to them. Piezoelectric actuators can give not only extremely accurate positioning resolutions, but also a very short range of motion. These actuators have very highly precise linear control.

Electro-mechanical actuators

They are similar to mechanical actuators except that they are operated using an electric motor. Motion control happens using this electric power.

To sum it up

Electric linear actuators are most suitable for the movement of final control elements which require linear movement. The rotary to linear conversion is done without any wear and thrust rod can transfer force directly to the final element. Many actuators are designed to be used in hazardous areas. They are operated by standard electronic units.

Literally hundreds of actuators are available in the market. One needs to understand the required force, rated speed, maximum stroke range, and whether explosion protection is needed or not. Then one can select appropriate linear actuator for their needs.

General Features of These actuators

1. Whenever required, they can be manufactured to be explosion proof.


2. They may also be manufactured for continuous positioning or for step control with very high accuracy.


3. Some actuators are stall proof with no need of position and they can be switched off depending on torque.


4. Gearing has very high mechanical efficiency.


5. Many actuators can covert rotary motion to linear motion, which cannot be seen from outside.


6. High end actuators have position and temperature sensors integrated with them.


7. The current and power supply to these actuators is provided via microprocessor controlled equipments.

Therefore linear motor ensures to give top notch productivity when it comes to industrial prorducts used for manufacturing purposes.