Electrostatic generator/motor rotor electrode system suitable for installation on the outer surface of an EMB rotor
View Patent ↗Electrostatic generator electrodes mounted on the outer surface of a fiber-composite rotor. The conducting strips are mounted with a slight tilt in angle such that the electrodes will experience no tension or compression effects as the rotor spins up or slows down. The compression would come about from effects associated with the Poisson Ratio. This change can eliminate any metal fatigue or loss of bonding that might have arisen if the electrodes were to be aligned with the axis.
1. An apparatus, comprising:
a cylindrical rotor having an axis of rotation and an outer surface; and
a plurality of rotor electrodes attached to said outer surface, wherein each rotor electrode of said plurality of rotor electrodes has a width dimension and a length dimension, wherein said length dimension is longer than said width dimension and is oriented at an angle ϕ relative to said axis of rotation, wherein said rotor is formed of a material, wherein said angle
ϕ
=
(
1
2
)
Cos
-
1
(
1
-
γ
1
+
γ
)
,
where γ is the Poisson Ratio of said material.
2. The apparatus of claim 1 , wherein said material is a fiber-composite.
3. The apparatus of claim 1 , wherein said each rotor electrode comprises an electrically conductive foil.
4. The apparatus of claim 3 , wherein said foil comprises aluminum.
5. The apparatus of claim 1 , wherein said each rotor electrode comprises a planar stack of thin metal wires, connected electrically to each other at one or both ends of the stack.
6. The apparatus of claim 3 , wherein each said foil comprises rounded edges made by folding a small width of the foil back on itself with the folded edge section being at the back.
7. The apparatus of claim 6 , further comprising two thin longitudinally oriented pieces of wire included in the folds to make more rounded edges.
8. The apparatus of claim 1 , wherein said outer surface is non-conducting.
9. The apparatus of claim 1 , further comprising a thin cover layer of fiber composite placed over said each electrode.
10. The apparatus of claim 1 , wherein said each rotor electrode is attached with adhesive to said rotor surface.
11. The apparatus of claim 1 , wherein said each rotor electrode is attached via a layered structure to said rotor surface, wherein said layered structure comprises a first adhesive layer attached to an elastomeric material attached to a second adhesive layer, wherein said first adhesive layer is attached to said rotor surface and said second adhesive layer is attached to said rotor electrode.
12. An apparatus, comprising:
a cylindrical rotor having an axis of rotation and an outer surface; and
a plurality of rotor electrodes attached to said outer surface, wherein each rotor electrode of said plurality of rotor electrodes has a longer dimension that is oriented at an angle ϕ relative to said axis of rotation, where the angle is selected to reduce the effects on said electrodes of geometric distortion produced as said rotor increases or decreases in rotational velocity compared to the case that would exist if said electrodes were aligned with said axis.
13. The apparatus of claim 12 , wherein said rotor is formed of a material, wherein said angle
ϕ
=
(
1
2
)
Cos
-
1
(
1
-
γ
1
+
γ
)
,
where γ is the Poisson Ratio of said material.
14. An apparatus, comprising:
a cylindrical rotor having an axis of rotation and an outer surface; and
a plurality, of rotor electrodes attached to said outer surface, wherein each rotor electrode of said plurality of rotor electrodes has a longer dimension that is oriented at an angle ϕ relative to said axis of rotation, where the angle is selected such that said rotor electrodes will experience reduced tension or compression effects, compared to the case that would exist if said rotor electrodes were aligned with said axis, as the rotor spins up or slows down.
15. The apparatus of claim 14 , wherein said rotor is formed of a material, where said angle
ϕ
=
(
1
2
)
Cos
-
1
(
1
-
γ
1
+
γ
)
,
where γ is the Poisson Ratio of said material.
16. An apparatus, comprising:
a cylindrical rotor having an axis of rotation and an outer surface; and
a plurality of rotor electrodes attached to said outer surface, wherein each rotor electrode of said plurality of rotor electrodes has a longer dimension that is oriented at an angle ϕ relative to said axis of rotation, where said angle ϕ is selected to reduce or eliminate any metal fatigue or loss of bonding that might have arisen if the electrodes were to be aligned with the axis.
17. The apparatus of claim 16 , wherein said rotor is formed of a material, wherein said angle
ϕ
=
(
1
2
)
Cos
-
1
(
1
-
γ
1
+
γ
)
,
where γ is the Poisson Ratio of said material.
18. An apparatus, comprising:
a cylindrical rotor having an axis of rotation and an outer surface; and
a plurality of rotor electrodes attached to said outer surface, wherein as the rotational velocity of said rotor increases, the rotor will contract axially and expand in circumferential length, where there exists on the surface of said rotor, helical lines for which there is neither expansion nor contraction is length, wherein said helical lines are located at an angle ϕ with respect to said axis of rotation, wherein said rotor electrodes are oriented with respect to the axis by said angle.
19. The apparatus of claim 18 , wherein said rotor is formed of a material, wherein said angle
ϕ
=
(
1
2
)
Cos
-
1
(
1
-
γ
1
+
γ
)
,
where γ is the Poisson Ratio of said material.