What Is a Motorized Actuator?

Motorized actuators are a family of mechanical devices that convert the rotary motion of an electric motor into linear motion used to perform work. The work output of these devices is utilized in a wide variety of applications, ranging from large ventilator shutters and conveyor chute diverters to tiny, ultra-precise optical stages in telescopes and camera lenses. The transfer or conversion of the motor's rotary output is generally facilitated by gear trains of various designs. The range of linear motion that a motorized actuator generates is controlled by limit switching or through very accurate stepper motor technology. The motorized actuator may generate its output in a single plane or two or three dimensions depending on the specific application.

Electric motors are among the best work-producing machines available. They are relatively small, yet powerful and reliable with stepper motor technology allowing for very accurate rotational control. In many applications, however, the challenge with any motor is converting rotary motion into linear work. One of the commonly-used solutions to this problem is the motorized actuator. By allowing the motor to drive, for example, a rack-and-pinion-type gear train, the rotational motion of the motor is translated into a straight line working output.

This type of setup can be contained in a surprisingly small package, making the motorized actuator an ideal solution for compact applications such as auto-focus and motorized zoom camera lenses. On the other hand, this type of motion conversion also benefits from the mechanical advantages inherent in gear drives, meaning that a relatively small actuator is capable of generating considerable leverage. These characteristics of motorized actuators along with the accuracy possible with stepper control sees them used in a wide range of applications from the previously-mentioned optical devices to large industrial hopper chute and conveyor diverters.

The motorized actuator may also produce its linear output in multiple planes. Most simple varieties are single dimensional and move a device in a straight line only while more complex types can move multiple stages or work platforms along additional XY and XYZ planes. These devices are typically used in precision-machining applications, where tool posts or work pieces rotate extensively during machining operations. In these units, each axis platform will generally feature a separate motor drive and gearbox. The extent of the movement or output of the motorized actuator is either controlled by mechanical or optical limit switches, or electronically via stepper motor control.