How to choose Electric Actuators

An electric actuator is a motor control component which uses an electric motor and position sensors to effect a specific mechanical movement.

Applications

These devices are used for fluid network valve control in the petroleum and chemical industries, and in water treatment systems. They regulate flow, dosage and fill levels, but also can be positioning mechanisms or generate mechanical force in presses and lifting machinery.

Technologies

Such actuators usually have single- or three-phase motors, and, occasionally, servo gears and brakes. They control pistons, cylinders and valves, which may have a manual back-up. Ball-screw linear models can move heavy loads.

Stepper motors are sometimes used for precise position and dose control. A position measurement system or a limit switch indicates that the desired position has been reached. Appropriate electronics can govern torque or mechanical force.

These devices are controlled by a relay (preactuator), by connection in series or by a four-20 mA current loop transmitter. Piezoelectric models provide high torque at low speed. They reliably maintain position when not energized.

How to choose

Choice will depend on the actuator's speed, power or torque control capabilities, or its positioning accuracy.