Saturday 21 February 2015

The Brushless DC Motor

          To understand why a BLDC motor is so effective, it’s important to have a good understanding of how it works. There are actually two different types, with different benefits and drawbacks. While either one will probably be effective for most jobs, you may wish to familiarize yourself with both types, just in case one would be more appropriate for your project or application than the other.

Any BLDC motor has two primary parts; the rotor, the rotating part, and the stator, the stationary part. Other important parts of the motor are the stator windings and the rotor magnets.

There are two basic BLDC motor designs: inner rotor and outer rotor design.


In an outer rotor design, the windings are located in the core of the motor. The rotor magnets surround the stator windings as shown here. The rotor magnets act as an insulator, thereby reducing the rate of heat dissipation from the motor. Due to the location of the stator windings, outer rotor designs typically operate at lower duty cycles or at a lower rated current. The primary advantage of an outer rotor BLDC motor is relatively low cogging torque.



In an inner rotor design, the stator windings surround the rotor and are affixed to the motor’s housing as shown here. The primary advantage of an inner rotor construction is its ability to dissipate heat.


 A motor’s ability to dissipate heat directly impacts its ability to produce torque. For this reason, the overwhelming majority of BLDC motors use an inner rotor design. Another advantage of an inner rotor design is lower rotor inertia.
BLDC Motor .



If you’re still not sure whether or not this motor is right for you, here is a basic breakdown of some of the primary advantages of the BLDC motor.

High Speed Operation – A BLDC motor can operate at speeds above 10,000 rpm under loaded and unloaded conditions.

Responsiveness & Quick Acceleration – Inner rotor Brushless DC motors have low rotor inertia, allowing them to accelerate, decelerate, and reverse direction quickly.
High Power Density – BLDC motors have the highest running torque per cubic inch of any DC motor.
High Reliability – BLDC motors do not have brushes, meaning they are more reliable and have life expectancies of over 10,000 hours. This results in fewer instances of replacement or repair and less overall down time for your project.

For details click here

See the working model of this motor here.

1 comment:

  1. Thank you so much for providing such great valuable information.

    ISL Products International Ltd. provides value-added, small brushless DC motor & brushless gear motors.

    ReplyDelete