Stacked flywheel rotor
Embodiments of the subject invention are directed to a flywheel rotor that includes two or more sub-rotors stacked one on top of another, in which each sub-rotor is rotationally symmetric and disk shaped, where the axial centers of each sub-rotor in the stack are rotationally aligned, and each sub-rotor has an upper and a lower journal that extends outward from the origin of the center section of the primary rotational mass of the sub-rotor. Each pair of adjacent sub-rotors in the stack has a lower journal of an upper sub-rotor that is disposed above an upper journal of a lower sub-rotor. Also, there is a joining mechanism between each pair of adjacent sub-rotors that fixedly connects the lower journal of the upper sub-rotor to the upper journal of the lower sub-rotor.
1. A flywheel rotor comprising:
a first sub-rotor and a second sub-rotor, each of the first and second sub-rotors being respectively rotationally symmetric around a respective center axis and disk shaped, the respective center axes being coaxial, wherein each of the first and second sub-rotors has a respective first journal and a respective second journal extending outward along the respective center axis;
a first joining plate and a second joining plate contacting each other, wherein the first joining plate contacts the respective first journal of the first sub-rotor and the second joining plate contacts the respective first journal of the second sub-rotor;
one or more fasteners connecting the first joining plate to the second joining plate, wherein the one or more fasteners create a rigid connection between the first and second joining plates; and
an alignment pin contacting a pre-drilled hole in the first joining plate and contacting a pre-drilled hole in the second joining plate.
2. The flywheel rotor of claim 1 wherein each of the first and second sub-rotors is made of a respective single piece of steel.
3. The flywheel rotor of claim 1 wherein each of the first and second sub-rotors is substantially a same size and shape.
4. The flywheel rotor of claim 3 wherein a respective thickness of each of the first and second sub-rotors is substantially between 8 and 14 inches.
5. The flywheel rotor of claim 3 wherein a respective diameter of each of the first and second journals at a respective furthest distance from the respective center axes is substantially between 4 and 6 inches.
6. The flywheel rotor of claim 1 wherein each of the first and second joining plates is respectively symmetric with respect to the respective center axes.
7. The flywheel rotor of claim 1 wherein a respective thickness of each of the first and second joining plates is in a respective range of .25 to 3 inches.
8. The flywheel rotor of claim 1 wherein each of the first and second joining plates is respectively made of steel.
9. The flywheel rotor of claim 1 wherein the one or more fasteners include a circular bolt pattern.
10. The flywheel rotor of claim 1 wherein the one or more fasteners are configured to impart compressive loading between the first and second joining plates sufficient to keep the first and second joining plates in positive contact under all operational loading conditions.