An Actuator is something that converts energy into motion. It also can be used to apply a force. An actuator typically is a mechanical device that takes energy, usually energy that is created by air, electricity or liquid, and converts it into some kind of motion. That motion can be in virtually any form, such as blocking, clamping, ejecting or many other types of motion.
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. 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. A standard linear actuator commonly has the motor as a separate cylinder attached to the side of the actuator, It is attached either in parallel way with the actuator or it sticks out to the side 90 degrees to the actuator. Motion control also plays an important role in the working of this device.The motor may also be attached to the back of the actuator. The drive motor has a solid drive shaft. This shaft is geared to the drive nut or drive screw.