Dream about magnet motor - sketch included

[Low-Q]

This is true but this is due to lack of proper design. When you use magnets on both sides the field will follow a near straight path through the iron. See below simulation where an iron piece is sandwiched between magnets.

Try that with a doughnut shaped piece of iron between the magnets. It wont work like a bar. The fluxlines will follow the shape.

[broli]

As always you are a hard one to convince Vidar . Below is a 3d simulation of a "dough-nut" iron piece between two split/flipped ring magnets.

www.youtube.com/watch?v=47aGAa2oERo

The field looks pretty straight on both sides doesn't it?

[Low-Q]

As always you are a hard one to convince Vidar . Below is a 3d simulation of a "dough-nut" iron piece between two split/flipped ring magnets.

www.youtube.com/watch?v=47aGAa2oERo

The field looks pretty straight on both sides doesn't it?

Oh! I see, but I wasn't thinking about magnetized though thickness but through the diameter.

If magnetized through thickness, I need a flux loop that can interfer with the inner rotors flux loop. But with the outer magnets this loop will be away from the inner rotor. That means that the inner rotor will see the external magnets, and not the outer rotor. The repulsion or attraction does not occour where the field lines are in parallell or points directly towards or is in line with eachother, but where the field lines deflects. A better explanation; where the field lines cross eachother with a given angle. If the angle is 0 or 180 degrees from eachother, there is no attraction or repulsion.
In your example, the field lines are straight and in parallell with the field lines from the inner rotor. Therefor it will not work.

My example in the video does not show the correct inner rotor. The center should be blue - not red, and magnetism should point radially from center and out, and not perpendicular to the computer screen. In FEMM I made an inner rotor from several magnets where magnetism pointed outwards (or inwards, or what you like), so one pole are in the center while the other is at the circumference.

Vidar

[broli]

Perhaps you are over complicating your own design. There should be no need for radial outward fields. Your motor is equally sound (or not) when both rotors are magnetized through thickness. This is the same reason why magnets facing pole up/down repel/attract each other.

[Low-Q]

Perhaps you are over complicating your own design. There should be no need for radial outward fields. Your motor is equally sound (or not) when both rotors are magnetized through thickness. This is the same reason why magnets facing pole up repell each other.

I know, but the magnetized iron in your previous example will not be repelled or attracted by the inner rotor in my design if that also was magnetized through thickness. That is the problem.


Vidar