Electric Motor Resource Center

What Are Ac Servo Motors?


AC servo motors are motion control components that convert alternating current to mechanical energy. Servo motors are not technically a class of motor but instead are any motor that is used in a closed-loop control capacity. Their closed-loop feedback system results in a fast, precise response that allows for careful, automated positioning.
 

These devices are common fixtures in equipment and systems that require a powerful yet compact motor. They are used in a wide range of applications by many different industries, particularly in equipment that must rotate between 90 and 180 degrees or to control parts in an angular or linear fashion. A variety of different motors can be used in a servo capacity, but AC servo motors are some of the more widely used.  

How Do Ac Servo Motors Work?

Servo motors operate through closed-loop position feedback to control motion in a speedy and precise manner. The specific mechanisms that enable the motor to accomplish this will depend on the class or type of motor that is used. AC servo motors are one variation. 

These electric motors use alternating current and are often designed with miniature squirrel cage style rotors and two-phase windings. Varying numbers of magnetic poles in the AC servo motor’s construction and the frequency of the applied voltage will affect the speed of the motor’s operation. Although most AC servo motors are made to rotate between 90 and 180 degrees, continuous servo motors can rotate a full 360 degrees.    

What Are Ac Servo Motors Used For?

A wide range of robotics and automated machinery, including computer numerical controlled (CNC) equipment, are all applications of servo motors. These motors allow for careful positioning and will run at slow, controlled speeds and are therefore used in systems that require deft, automated controls. Since they can also be made quite compact, they are used in smaller devices including various radio-controlled tools and appliances.

Where To Buy Custom Ac Servo Motors?

Standard AC servo motors are available as commercial, off-the-shelf devices from many different providers. When custom AC servo motors are required, however, the services of an electric motor manufacturer will be helpful.

Smaller, independent manufacturers will often work directly with engineers and other professionals to realize a custom motor design. This may be done by modifying an existing plan or by building a new type of AC servo motor from scratch. 

Custom AC rotors are also an integral component in the creation of a unique servo motor. Some electronic motor manufacturers will build stator and rotor kits that are made to highly specialized performance requirements. These and other components can have a major impact when meeting specialized performance parameters. The materials used to make parts of an AC servo motor can also be customized for non-standard applications an operational environments.   

When sourcing a custom AC servo motor, rotor, or related device, it’s often necessary to have technical drawings and other specifications prepared. Some manufacturers may provide additional services to help create these custom motor essentials. 

Can Dc Motors Be Servo Motors?

DC motors are sometimes used in a servo motor capacity. When DC motors are used in this way, the brushless variety, or BLDC motors, can provide better performance.

Ideally, a servo motor should be able to provide smooth and precise movement. The type of current fed into the motor, whether alternating current or direct current is not as much of a factor as the motor’s ability to operate reliably in a closed-loop control system.