Self-adjusting airgap motor/generator for flywheel system

DETAILED DESCRIPTION We claim: 1.
A flywheel system, comprising: a first shaft having a longitudinal axis; flywheel means, comprising: a flywheel capable of rotating about said shaft having a flywheel inner diameter; a plurality of permanent magnets disposed in said flywheel inner diameter; and said flywheel means having an inner diameter which is tapered; at least one bearing which facilitates said rotating of said flywheel about said first shaft; a second shaft having substantially the same longitudinal axis as said first shaft; a stator, disposed on said second shaft, having a stator outer diameter disposed at least partially within said inner diameter of said flywheel means, which couples electromagnetic energy to and from said flywheel means and which moves axially along said longitudinal axis; said stator outer diameter and said inner diameter of said flywheel means having shapes that create an adjustable gap between said stator and said flywheel means as said stator moves axially along said longitudinal axis; said stator being rotatable about said longitudinal axis; self-engaging means for automatically decreasing said gap in response to electromagnetic torques exerted on said stator when said flywheel is being spun-up and spun-down, thereby increasing electromagnetic forces between said stator and said flywheel; and self-disengaging means for automatically increasing said gap when said flywheel is freewheeling, thereby decreasing electromagnetic drag on said flywheel.
2.
The flywheel system of claim 1, wherein said self-engaging means comprises grooves having a bi-directional contour embedded in said second shaft.
3.
The flywheel system of claim 1 wherein said self-disengaging means comprises an axial spring around said second shaft.
4.
The flywheel system of claim 1, wherein said adjustable gap is set to exert minimal electromagnetic drag on said flywheel when said flywheel is freewheeling.
5.
The flywheel system of claim 1, wherein said stator comprises a plurality of coils wound around laminations to create a plurality of electrical phases