The latest advancement in power tools is the use of brushless motors. But what exactly is a brushless motor, and what are its benefits?
To fully understand this technology, let’s take a quick look at the existing technology: brushed motors.
How Brushed Motors Work
In a typical electric motor, there are permanent magnets (stator) on the outside, and a spinning armature (rotor) on the inside. The rotor contains an electromagnet. When electricity passes through the electromagnet, it creates a magnetic field inside the rotor that attracts and repels permanent magnets in the stator.
However, to make the motor spin 360 degrees, it’s necessary to change the polarity of the electromagnet, and a pair of brushes helps do that.
Motor brushes aren’t brushes at all, but small blocks of carbon connected to a compression spring. The brushes press against spinning electrodes attached to the rotor. As the electromagnet spins, the brushes change the magnetic polarity.
Brushed motors are reliable, relatively efficient and inexpensive to manufacture, but they have distinct limitations.
First, carbon brushes eventually wear out and must be replaced. As the motor