New design: it fits! :)

Posted on December 28, 2007


The human brain is a fantastic machine indeed. After 10 years of complete neglect, all the trigonometry I ever learned had completely vanished. 😦 I couldn’t even remember the Pythagorean equality!!! And yet, after one week’s training, I learned it all back again.

So, without further ado, here is the fruit of my labour.

I think a lot of people will enjoy this design a lot more, because it actually looks like a motor! 🙂 The other design (axial flux) was harder to interpret from the drawing. Here you can see the stator in the middle, and the double rotor(s) moving on the outside and inside of the stator. All measures are accurate to the millimetre (actually, to 1E-9 m), so the scale is absolutely realistic.

There’s still a lot of stuff missing, the model still needs material properties in all the right places before FEMM can compute it electromagnetically. But as soon as it is complete, we can start with a whole new set of simulations and “what if”s…

The script is highly reusable; you give the basic dimensions of the motor (inner radius, outer radius, air gap, etc.), as well as the dimensions of the magnets, and then it draws the motor just right! It can even let us use more than one magnet per stator pole; this way we reduce the air gap thickness by emulating a curved magnet with a set of smaller flat magnets. 😉

It would be really cool if you would give me ideas on optimization algorithms to improve the design. For example, we could make a script that keeps changing the size of the magnets and recomputes the model to find the highest possible torque as a function of magnet type…

Well, Happy New Year to everyone.