Electric Motor Resource Center

What Are Induction Motors?


Induction motors are electric motors that use alternating current (AC). They're also known as asynchronous motors. 
 

Induction motors convert electrical energy into mechanical energy and they are used in many different types of equipment to control motion.

Induction motors are economical to produce and maintain. They perform with good reliability and do not require regular servicing or updates. They are employed in a wide range of applications and used by many industries because of these advantages.

How Do Induction Motors Work?

Induction motors operate as electric current is introduced to the rotor. Here, torque is produced when the magnetic field of the stator’s windings interacts with the electric current via the rotor. In induction motors, the rotor is either wound, meaning it is formed with wire laminations or it is what’s known as a squirrel-cage. This is where the magnetic field is produced that causes the rotor to spin.    

What Are Different Types Of Induction Motors?

Induction motors are categorized into two main types, single-phase and three-phase. Three-phase induction motors are self-starting and used in heavier, industrial applications that have larger load and operational requirements. Single-phase induction motors are used in simpler systems that require only light and standard operational demands, such as household fans and other motorized electronic appliances.  

What Are Common Applications Of Induction Motors?

Induction motors are incorporated into many different industrial, commercial, and domestic electronics. Single-phase induction motors are used in machinery and appliances that require fairly basic rotation of parts. These applications include fans, pumps, mixers, vacuums, compressors, light-duty drills and rotary devices, electronic toys, etc. 

Three-phase induction motor applications include more rugged, high-power equipment, such as electronic lifts, cranes, hoists, milling machinery, lathes, pumps and extractors, large capacity fans and blowers, etc.   

What Are Advantages Of Induction Motors?

Induction motors carry many advantages. They are utilized when manufacturers are seeking lower cost in building their equipment and ease of maintenance. Induction motors seldom require repair or adjustments to maintain performance. The simplicity of their design and the fact that they are self-starting means that induction motors do not require complex configuration or additional components.

Induction motors are quite durable and can be incorporated into equipment that may undergo a lot of wear-and-tear during regular use. These motors are also employed as variable-frequency drives in machinery where variable speeds are needed. Induction motors can bring additional energy savings to such applications.      

Where To Buy Induction Motors? 

The best way to source or purchase induction motors depends on how they will be used. If a single or small quantity of induction motors are needed for a small project, prototype, or hobby, then standard performance single-phase and three-phase induction motors can be purchased as off-the-shelf devices from electronic component suppliers.

OEMs that require standard induction motors for mass production of a product may similarly rely on commercial, off-the-shelf motors, which can be purchased wholesale or in bulk from motor manufacturers and distributors. 

If induction motors are needed for more specialized or high-demand applications, such as industrial, aerospace, or defense equipment, it’s beneficial to source such products directly from an induction motor manufacturer. For example, the services of a custom motor manufacturer may be required when 400 Hz induction motors are needed for use aboard various aircraft. 

Dedicated motion control manufacturers can provide more options when it comes to heavy-duty or high-performance parts that affect a motor’s performance. An electronic motor manufacturer can also customize elements such as the stator and rotor, squirrel cage, and housing. Such customizations can better ensure that the motor will seamlessly integrate into the end product or system and perform as expected.      

What Is The Difference Between Synchronous And Asynchronous Motors?

Synchronous motors and induction motors are both AC electric motors but they operate and are constructed in very different ways.

Synchronous motors are fed with a DC supply and feature a set number of poles within the stator winding or a permanent magnet. Induction motors are fed with an AC supply and use a wound rotor or a squirrel cage with end rings.

In synchronous motors, slip rings are essential to the process of feeding the power supply to the rotor windings. In an induction motor, slip rings are not required.

With regard to operation, the stator poles of synchronous motors run at synchronous speeds with the rotor. An induction motor will run at asynchronous speeds, with the rotor always running slightly slower than the rotation of the stator.