There are many varied uses for industrial encoders, here we have listed just a few examples.
The following are a few practical examples of common encoder installations.
Motor Speed / RPM readout is the most common way that encoders are used. Typically the encoder is mounted directly to the end of a motor via a shaft. The critical parameter of measurement is motor speed whereby the encoder provides feedback to a drive. The drive can then verify that the speed and direction is correct ensuring that whatever the motor is driving runs safely and smoothly and does not run out of control or behave erratically in applications where precise speed is a requirement.
Web Speed / Tension Control is an application in which an encoder is mounted to a motor as well as a tension roller. Any unevenness in the rotating speed of the tension roller is fed to a controller which sends a signal to the drive motor to adjust in order to maintain an even tension proportion between the web roller and drive motor. Maintaining optimal web tensioning is critical in assembly and conveyor applications or in roll tensioning applications designed to prevent tearing, backlash or other potential injury to machine operators.
Linear Measurement / Cut-to-Length is a form of linear measurement whereby an encoder is mounted on a lead screw or measuring wheel to prevent a user from having to physically measure (using a tape measure or inaccurate hand mark or eye estimate) a length of material before it is cut. Since an encoder delivers a fixed number of pulses in a revolution, a device can be scaled to increment at a designated length per pulse. This device may be a preset counter or PLC that in turn has a relay output that can be set to operate when the desired length is reached to ensure a precise and accurate cut every time.
Multi- axis control can be achieved using incremental or absolute encoders. They need to be high resolution accurate devices and are used in a variety of automated applications in manufacturing and research. Radar antenna, robotic arms or satellite dish rotation are good examples of this type of application.
Position Measurement / Backstop Gauging position measurement applications are similar to a cut to length application whereby the encoder is used to make sure that the unit, typically a machine tool, does not exceed a preset position or direction of travel. Very often this is combined with a determination of the speed of travel of the table, tool head, or similar component to ensure that the machine does not over travel. Although limit switches can be used in backstop applications, encoders are more shock resistant and tend to last longer.
Position Measurement / Conveying is another common industry application where encoders are widely used to monitor and control conveyor speed and position. Similar to a motor feedback application, encoders are attached to a motor, intermediate axle shafts, or to both. The critical parameters of measurement are motor speed and incremental movement. In this case the encoder can control both the conveyor speed and position.
Position Measurement / Spooling is another application where encoders are ideally suited. The encoder is mounted to the shaft of a spool, the connected controller keeps track of the length and speed of the take up material being spooled based on feedback from the encoder.