Core vs coreless motors.

[Neo Rules]

If all things are the same in an axial flux motor, (winding shapes, diameter, length, etc.)

How predictable is the difference between Iron core, air core, and soft ferrite cores performance.
I have been told silicon steel core would provide better continuous torque with a lower max rpm, efficiency reduction, and increased cogging torque.
Air core would be the most efficient with lower torque, higher rpm and almost no cogging.
And ferrite would be the worst as it would saturate and still have cogging with lower rpm.

Everything else being the same is there a general percentage difference between iron core and air core?

Tnx
JC

 

[Gr8blu]

IN the sizes of machines I work with, the choice between iron- and air-core designs comes down to two things: price, and operating frequency. Air-core designs are generally going to be more expensive, for a couple of reasons I won't go into here. But they will work MUCH better in high-frequency applications because the overall inductance of the winding will be lower (the air doesn't "store" energy like the iron does). Laminated cores are better than solid cores for much the same reasons - and have the corresponding price differential as well.

Bottom line: there is ALWAYS a best tool for the job. Not all tools will do all jobs equally well. Choose wisely.

Converting energy to motion for more than half a century