Brushless Motor 101

What the hell is a brushless motor, and why the brushless electric tools better than those who brushed motor?

While the brushless motor is not exactly a new technology, brand power tools are just beginning to discover their full potential in power tools. Many brands are designed brushless tools from the ground up, and in addition to other high-end features to deliver more for the price gains.

M12 and M18 engines Fuel brushless Milwaukee’s lineup seems to be the fastest growing, but other brands are beginning to catch up with their own innovations.

Now, at the end of 2014, there are exercises brushless, drivers and impact wrenches, saws, rotary hammers, and the oscillating tool. There is even a brushless Band, and another brand appears with a brushless Nailer frame.

With new brushless tools coming out all the time, even by the consumer brands like Craftsman, perhaps you’re listening brushless thrown around a lot in product descriptions and marketing, and self ask what it all means.

Here’s a quick primer on brush motors, brushless motors, and why the tool is equipped with brushless motors so darned good.


Brushed Motor

A basic brush motor with an armature (rotor), switches, brush, shaft and permanent magnets. Current is applied through the brushes, which are exposed to physical and electronic switches. Current then passes through the armature coil, creating a magnetic field.

The magnetic field generated by interaction with the permanent magnet surrounds the armature causing the armature to rotate around the shaft. If you apply the current larger, such as when you pulled the trigger of a cordless power tool more, you will create stronger magnetic field in the armature, leading to greater interaction force and therefore rotate faster than.

As you can see in the diagram, marked in red, the brushes are in contact with the commutator. Friction between the brush and switches results in a slight drop in the rate of heat loss and energy. Additionally, the brushes may need to be replaced periodically as they wear out over time with use.


1st Generation Brushless Motor

In a brushless motor, no brush, and so there is no physical contact can result in energy losses due to friction. Instead of the armature is placed on the rotor with permanent magnets fixed to the surrounding casing (stator), a permanent magnet is placed on the rotor brushless electromagnetic coil with the armature in fixed positions around it.

In a brush motor, the switch reverses the flow through the armature winding, flip the magnetic field to the rotor continues to spin. In a brushless motor, an electronic control phase shift of the current through the armature coils in the exact timings to perform the reaction turned.


Brushless motors more expensive to design and manufacture, but they are usually more efficient than brushed motors. This leads to:

  • less maintenance and longer life
  • more power
  • longer runtime

Typically, the brand has a choice in how they balance power and runtime of a tool for optimal performance. Some may be inclined to make a more powerful engine, others may be inclined to make one that lasts longer before swapping batteries or recharge is necessary.

Brushless motors have become powerful enough to boast that many brands of wireless tools brushless their superior “performance records like.”

And, combined with the latest generation of high-capacity Li-ion battery pack (we at 5.0Ah), brushless tools offer better than ever wire runtime as well.


When this article was first published in early 2012, Dewalt and Milwaukee are the first mainstream brand to come out with brushless power tools. We anticipate that other brands will follow the trend, and brushless motors will be incorporated into other tools and driver training.

Now, there seems to be no limit to the types of tools that can be redesigned with brushless motors. Also, as mentioned earlier, the brand power tool sometimes develop other advanced features into tools of their brushless.

For example, brushless fuel M12 Milwaukee drilling of a “chuck instead of 3/8” 1/2. impact drivers and wrenches brushless Many brands’ current offer speed settings and electronic torque allows you to dial down the power depending on the application and fastener sizes.

With all the benefits of brushless electric tools, it’s no wonder why they topped the brushless tool in many fields.

In our best cordless drill, impact driver the best, and the Wireless Tools best oscillation recommendations, tools brushless highest title.

There is a downside to the wireless tools brushless – they are expensive. They are more expensive to design and manufacture, and therefore more cost to the end user. The bright side is that brands usually designed brushless tools with advanced features and improved capabilities to help you see through higher prices. Kits usually come with Li-ion battery packs to last most, and to make them even more attractive.


A comparison with brushless motor brush comparison is not exactly black and white as described. For example, moving the armature from the rotor to the stator also results in reducing the weight and volume of the radial distribution of the rotor. In other words, the rotor of a brushless motor is usually much lower moment of inertia than a brushed motor. This means that a propeller rotating brush is more resistant. (Imagine an ice skater spinning with outstretched arms than with them.)

So it is not just about improving the effectiveness of reducing energy losses due to friction switching broom. Other fundamental advantages of brushless motors include improved heat dissipation, flatter torque, electrical noise, and greater power output.

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