Actuator

An actuator is a <a href="/facts/Machine_element/cV69bkb9">component of a machine</a> that produces <a href="/facts/Force/533Q1uzq">force</a>, <a href="/facts/Torque/KcrcvNtV">torque</a>, or <a href="/facts/Displacement_(geometry)/jkmEfS3C">displacement</a>, when an <a href="/facts/Electrical/hNC8D65W">electrical</a>, <a href="/facts/Pneumatics/QzkvCCpk">pneumatic</a> or <a href="/facts/Hydraulic_fluid/6ySxLhq5">hydraulic</a> input is supplied to it in a <a href="/facts/System/hmqQ4ASX">system</a> (called an actuating system). The effect is usually produced in a controlled way. An actuator translates such an input signal into the required form of <a href="/facts/Mechanical_energy/gI4oMzoY">mechanical energy</a>. It is a type of <a href="/facts/Transducer/YS7zfv9d">transducer</a>. In simple terms, it is a "mover".
An actuator requires a control device (which provides <a href="/facts/Control_signal/6d4zgUj7">control signal</a>) and a source of <a href="/facts/Energy/wd8PrQM7">energy</a>. The control signal is relatively low in energy and may be <a href="/facts/Voltage/EN2po6N2">voltage</a>, <a href="/facts/Electric_current/Dc1xdnUX">electric current</a>, <a href="/facts/Compressed_air/KEjxE7DG">pneumatic</a>, or <a href="/facts/Hydraulic_fluid/6ySxLhq5">hydraulic fluid</a> <a href="/facts/Pressure/eyc37GRG">pressure</a>, or even human power. In the electric, hydraulic, and pneumatic sense, it is a form of <a href="/facts/Automation/3YlF2K5q">automation or automatic control</a>.
The displacement achieved is commonly linear or rotational, as exemplified by <a href="/facts/Linear_motor/cLBAMYtq">linear motors</a> and <a href="/facts/Rotary_motor/ArD7BGDa">rotary motors</a>, respectively. Rotary motion is more natural for small machines making large displacements. By means of a <a href="/facts/Leadscrew/8vsogz4d">leadscrew</a>, rotary motion can be adapted to function as a <a href="/facts/Linear_actuator/37YgKUP3">linear actuator</a> (which produces a linear motion, but is not a <a href="/facts/Linear_motor/cLBAMYtq">linear motor</a>).
Another broad classification of actuators separates them into two types: incremental-drive actuators and continuous-drive actuators. <a href="/facts/Stepper_motor/sksWdPsj">Stepper motors</a> are one type of incremental-drive actuators. Examples of continuous-drive actuators include <a href="/facts/DC_motor/sUBwD8py">DC torque motors</a>, <a href="/facts/Induction_motor/DgTnMmJM">induction motors</a>, <a href="/facts/Hydraulic_motor/vvF2RMGs">hydraulic</a> and <a href="/facts/Pneumatic_motor/GmH8tW1U">pneumatic motors</a>, and piston-cylinder drives (rams).

Actuator open-in-new

Actuator