Linear Actuators

Linear actuators serve many different purposes in a wide array of applications, like industrial machinery and computer science. It mechanically moves in a linear direction to raise or descend assorted items. There several types of linear actuators, each with their own features and purpose.

What is a linear actuator?

An actuator is a mechanical device that moves. A linear actuator is simply an actuator that moves in a linear, or straight, direction. This means that the device moves in only two directions. While there are various ways to accomplish this, the most common forms of linear actuators use a rod, switch, or slider that extends and retracts on a track. They can be moved manually or electrically through volts of power. They can be used for many things, from industrial purposes in machinery to wheelchair ramps in vehicles or hydraulic switch doors in rockets.

What are the distinct types of these actuators?

While there are hundreds of variations of linear actuators, there are five main types. These types include the following:

  • Mechanical - These linear actuators work by switching rotary motion into linear motion. This is usually done by screws, a wheel and axle, or cams. Some of these simply pull while others only push. These don’t use DC electric motors like other versions.
  • Hydraulic - This type is designed using a hollow cylinder with a piston inserted in it. This creates an unbalanced pressure of liquid that forces an external object to move. They can hold constant force and torque at high speeds and are usually used alongside hydraulic pumps.
  • Pneumatic - These actuators use compressed gas instead of liquid to force an external object. It uses a piston inside a chamber but only needs an air compressor as a power source.
  • Piezoelectric - This type runs on the piezoelectric effect, which occurs when certain materials expand with the application of a specific number of volts. Volts expand material within the actuator, which then makes it move.
  • Electro-mechanical - These are like mechanical actuators, but they use DC electric motors with volts instead. Rather than creating a rotary motion, the DC electric motor creates a linear motion.
What can you use these for?

Linear actuators can be used in anything that is designed to move. They can be found in cellphones, cars, robots, and even rockets. Mechanical linear actuators are not typically used in faster-speed applications and are usually seen in hoists, chain drives, and belt drives. Car jacks and jackscrews also use these types. Hydraulic actuators are typically made for high-force, high-speed uses, but they can be found in more familiar products like hydraulic carjacks as well. Pneumatic linear actuators can be found in things like air compressors, but they are versatile enough to be used in areas of extreme temperatures.