Outrunner question

[mechplas]

I am feeling very bored and am going to ask,....maybe a stupid question.

Why are brushless motors sometimes called Outrunners?

Is it because they run on the outside or because they outrun the brushed motor?

I jumped into electric couple of weeks ago...I'm catching up with their "lingo".

[Adrianli]

There are inrunner and outrunner brushless motors.

Inrunner motors - For high RPM.

Outrunner motors - For high torque.





Any other experts to further explain???

[csisfun]

I think it's because:

The case of the outrunner is the thing spinning the shaft.

An inrunner's stator (i think) moves.

[zed]

Basically, there are 2 different kind of brushless motors, the inrunner and the outrunner.

The inrunner looks just like your typical brushed motor, just that there are no brushes in it. The shaft is attached to the stator (the part inside with all the windings), while the magnets are attached to the casing, thus the stator spins together with the shaft.

As for the outrunner, the outer can of the motor is attached to the shaft while the inner stator is fixed (to the mounting hardware). YOu will see the entire can spin when the motor runs. This creates a much higher torque.

Outrunners are usually used without gearboxes because of lower rpm/v. The absence of the gearbox also creates a really "silent" flight. One thing to note when you use it is to make sure nothing rubs on the spinning can.

Hope this helps.

Zed

[Super-Hornet]

Here is my explaination.. Maybe repeated:

OutRunner
---------
Like computer fan, stepper motor, CDROM motor. You will have wire coil onto a stator and the stator is at the center of the motor core. The magnet, it is glue/fixed onto the outer ring of the motor. When spinning, the outer-ring is turnning...Therefore, outrunner.

InRunner
---------
Like bicycle dynamo, Himaxx motor. You will have wire coil onto the outer ring. Some do have stator like of the outer-ring and some just a wire coil (Like Himaxx). The inner ring is a cylindrical (I think Mega is Hexagon shape) shape of magnet. When running, the inner ring that is turning...Therefore, inrunner.

Super-Hornet

[SonicBoom]

Magnet on shaft is inrunners.
Magnet on can (casing) is outrunners.