Inside be quiet!
How does a 6-pole motor work?
In the advertisements for our Silent Wings 3 fans the "6-pole motor" is often emphasized as being one big advantage. But what does this mean exactly? And what differs a 6-pole motor from its lesser-poled siblings?
The structure of BLDCs is as follows: The outer shell (the rotor) consists of integrated magnets with four poles, while the inner core (the stator) features several copper wire spooles - four or six, hence the names "4-pole" or "6-pole". This number has to be divisible by two, as a magnet field inevitably requires two magnetic poles in order to work. In a 6-pole motor the copper spooles fill up most of the available space inside, which is good for efficiency as there is almost no loss due to literal air pockets. The amount of copper determines the ultimate fan speed, as it directly influences the strenght of the resulting magnetic field.
As soon as direct current is led into the system the copper spooles get charged electrically, which transforms them into magnets - and due to the laws of physics they immediately start to interact with the magnets in the rotor. Thanks to this parallel attraction and repulsion of six very dense poles the rotor rotates very evenly, reliably and without much vibration. Now a very valid question is: Why not include even more poles? Well, there are strict limitations: The more poles have to be crammed into the limited stator space, the smaller the spooles have to be inevitably. Also more material increases production time and price, while in the worst case the efficiency sinks. In our experience six poles are the best compromise of high performance and low price.
In the end it's all about reliability, longevity, efficiency and of course silence - our name is a promise, after all. And in all cases the 6-pole motor is the champ, which is why we use it to full effect in our fan crown jewels, the Silent Wings 3.