Talk:Outrunner

In the absence of an official name, I introduce the name electromagnetic gearing.

2014-Feb-12 Thanks for introducing this. For the novices who would likely be reading this Wiki, what do the letters N and P refer to? Which is the number of magnets on the rotor and which is the number of "teeth" on the stator? How are the magnets aligned? Sometimes there are more magnets than teeth and sometimes less. What difference does this make in the design and performance? Are outrunners always about "magnetic gearing" or is this configuration just a way to get a larger diameter air gap and more magnetic shear area for a given volume of motor?

Some ideas for expanding this article: Don't these motors tend to be very coggy? A cog is the magnetic indentation caused by the attraction of the iron stator to the magnets. Cogginess is affected by design and shape of the iron and magnets. What are the benefits of more or less cog magnitude? Turning the motors I've seen by hand and its like turning a stepping motor, very obvious indentations, and running them the whole structure vibrates and has harmonic resonances, at certain speeds the whole structure sings and is noisy. What geometric (physical or design) factors determine how coggy a motor is and how do you measure and specify the degree of cogginess? How does the various combinations of N & P affect cogging? What about skewing the slots? What about slotless configurations? And what is the frequency (or how many cogs per rotation for a given N:P ratio?) Does the intensity of cogginess remain constant for a given design?

How does the design of the backing iron affect the motor? What motor performance characteristics are compromised by making the backing iron lighter and cheaper? What type of magnet structures are used in practice?

Many of these motors struggle to get to 80% efficiency. Doesn't matter for a CD motor. But for a battery operated 1kW motor used in model planes and many other applications, that's a lot of heat and wasted energy. What are the limiting factors? What would it take to get to over 95% efficiency? — Preceding unsigned comment added by 125.237.198.23 (talk) 07:39, 12 February 2014 (UTC)

Rotor = permanent magnets / stator = coils

In the paragraph: 'Common stator pole/magnet pole configurations' to my opinion the heading would be better: 'Common stator poles (coils) / rotor permanent magnets poles configuration'

In the following brief description:'P denotes number of stator magnets, N denotes number of rotor poles' the terms 'stator' and 'rotor' should be reversed!!

My name here is 'Lodidol' an I did not log in because of difficulties doing the whole lot from my phone! 46.114.4.24 (talk) 09:02, 1 May 2019 (UTC)