I'm currently in the works of developing a vertically suspended flywheel, and I'm trying to figure out the best method to convert rotational energy to electrical energy and vice versa. I don't want to just slap on a regular AC motor/generator for several reasons: it would probably be bulky, and interior bearings would introduce more frictional losses to the system.
I came up with this idea (image below) where a magnet is suspended inside a larger coil. As AC current is passed through the coil, the magnet will spin to align itself with the new pole orientation. Conversely, the spinning magnet would induce AC current through the coil. Just as a note, I will definitely be increasing the number of loops and choosing a magnet with a high flux density.
Would a system like this work, and more importantly does it have the potential to reach high efficiency, hopefully comparable to a standard motor/generator?