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What are servo motors and how do servo motors work?

Servo motor can be used in many industrial and commercial systems and products such as metal cutting and forming machines provide precise motion for milling( called CNC servo motor or industrial servo motor), lathes and bending for metal fabrication, robotics where a servomotor is used at every “joint” of a robot to perform its precise angle of movement; The camera auto focus uses a servo motor built into the camera that corrects precisely the position. And with antenna positioning systems where servo motors are used for both the positioning of azimuth.

Servo motor applications are most commonly used in closed loop systems where precise position control is commonly found in industrial and commercial applications.

In this lesson, you will learn about motion control using different types of servomotors available, and how servo motors work.

In this lesson we will discuss what a servo motor is and how it works, so let’s first determine what a servomotor is and examine some unique features of the types of a servomotor and its application.

What is  Servo Motor?

Let’s begin, with the servo motor basics. Industrial servo motor are part of a closed-loop system and are comprised of several parts namely a control circuit, servo motor, shaft, potentiometer, drive gears, amplifier, and either an encoder or resolver.

A high speed servomotor is a self-contained electrical device, that rotates parts of a machine with high efficiency and with great precision.

The output shaft of this servomotor can be moved to a particular angle, position and velocity that a regular motor does not have.

The servo motor utilizes a regular motor and couples it with a sensor for positional feedback.

The controller is the most important part of the Servo Motor designed and used specifically for this purpose.

The CNC servo motor is a closed-loop mechanism that incorporates positional feedback to control the rotational or linear speed and position.

A type of encoder serves as a sensor providing speed and position feedback. This circuitry is built right inside the motor housing which usually is fitted with a gear system.

How do servo motors work?

The working principles of an AC servo motor are based on the construction of two distinct types of AC servo motors, they are synchronous servo motor and asynchronous servo motor (induction motor).

The synchronous AC servo motor consists of a stator and rotor. The stator consists of a cylindrical frame and stator core.

The armature coil is wound around the stator core and the coil is connected to a lead wire through which current is provided to the motor.

The rotor consists of a permanent magnet and this differs from the asynchronous induction type rotor in that the current in the rotor is induced by electromagnetism therefore these types are called brushless servo motors.

When the stator field is excited with voltage, the rotor follows the rotating magnetic field of the stator at the same speed or synchronized with the excited field of the stator, and this is where the synchronous type is derived.

With this permanent magnet rotor, no rotor current is required so when the stator field deenergizes and stops, the rotor also stops. These motors have higher efficiency due to the absence of rotor current.

When the position of the rotor concerning stator is required an encoder is placed on the rotor and provides feedback to the servo motor controller.

The asynchronous or induction AC servo motor stator consists of a stator core, armature winding, and lead wire and the rotor consists of a shaft and the rotor core winding.

Most induction motors contain a rotational element, the rotor or squirrel cage.

We supply plenty of 100% original brands of servo motors, like Panasonic servo motors, YASKAWA servo motors, Bosch Rexroth servo motors, and Mitsubishi servo motor,  If you need to know more information about them, please feel free to contact us.