An actuator is a device that combines a power source with mechanical components to perform mechanical operations. An electric motor is an example. The ability to control force, speed, angle and other parameters related to the operations performed by the actuator means that these devices play an indispensable role in mechatronics.
How the actuator works
The actuator uses a combination of a motor and a mechanical drive mechanism for operation. By transmitting the motor torque to the drive mechanism, the actuator can convert it into linear or helical motion as well as rotational motion. This enables the actuator to drive a wide variety of equipment.
The actuator can be used to convert the rotation of a motor or other drive source into different types of motion, such as the following motions.
Straight line movement. Applications include the opening and closing movement of automatic doors.
Move back and forth at a fixed angle. Applications include robot joints and vehicle stabilizers (active suspension).
Two linear movements at right angles to each other. Applications include seismic isolators for buildings.
A rotation angle of 360° or greater is used in applications such as robot joints.
Combination of linear and rotary motion.
The history of the actuator
Watermills and windmills can also be considered as actuators. In this sense, the history of these devices can be traced back to ancient times.
However, it wasn't until the industrial revolution was underway that actuators in the modern sense appeared. The popularity of steam engines and the emergence of different types of internal combustion engines have led to the development of various actuators used to drive machinery.
Equipment such as presses, elevators, and suspension bridges operated by water pressure began to appear in the 19th century, with the increase in the use of pneumatic technology in railway vehicles such as air locks or for opening and closing automatic doors. Hydraulic technology began to be used in the 20th century. In 1979, the world's first wheelchair with an electric actuator was invented, which has been widely used in many fields.
Nowadays, electric actuators driven by small motors are popularized in many products such as robots, automobiles and household appliances, and have laid the foundation for our industry, society and daily life.
Although there are many different types of actuators, they can be divided into the following categories according to their driving methods.
An electric motor is a typical example of an electric actuator. Because they can be easily reduced in size, they are suitable for a variety of products.
Servo motors provide position, speed and torque control.
The stepping motor has the precision that it can rotate at a small fixed angle.
They work on the same principle as an electric motor, but can provide linear motion.
These actuators are driven by the pressure of hydraulic oil. Their ability to provide a lot of power means they can be used in construction machinery and other heavy equipment.
The pressure of the hydraulic cylinder causes the piston in the cylinder to move up and down.
An electric motor that rotates by hydraulic pressure.
These actuators are driven by compressed air. They have a simple mechanical design and flexible operation mode.
The piston in the cylinder moves up and down under the action of air pressure.
An electric motor that rotates by air pressure.