Electrostatic generator electrode-centering and seismic-isolation system for flywheel-based energy storage modules
View Patent ↗Robust electro-static (ES) device embodiments, with application to energy storage flywheels as an example, are described that provide reliable, high-efficiency operation in the presence of thermal and mechanical perturbations, as well as seismic events. Electro-static generators and motors, when augmented with magnetic bearings, passive three-dimensional stabilization techniques and dynamic touch-down bearings, enable robust performance in the face of these environmental concerns, as well as efficient operation during typical operational sequences, including spin-up and steady-state modalities.
1. An apparatus, comprising:
an open cylindrical rotor having a central axis of rotation and an inner surface;
a first support structure that is stationary relative to said rotor;
a first annular element having its outermost edge attached to a first location of said inner surface of said rotor;
a second annular element attached to said first support structure, wherein said second annular element is positioned in proximity to said first annular element, wherein at least one of said first annular element and said second annular element is configured to magnetically attract the other of said first annular element and said second annular element;
a second support structure;
a triplet array comprising:
a first magnetic annular element attached to a second location of said inner surface of said rotor;
a second magnetic annular element attached to said second support structure
a third magnetic annular element attached to said second support structure, wherein said second magnetic annular element and said third magnetic annular element are positioned on opposite sides, one to another, of said first magnetic annular element and both magnetically repel said first magnetic annular element;
a base and at least one compression spring attached to and located between said second support structure and said base;
a guide tube fixedly attached to said base; and
a guide shaft fixedly attached to said second support structure, wherein said guide tube is configured to receive said guide shaft.
2. The apparatus of claim 1 , wherein said first annular element together with said second annular element comprise a configuration selected from the group consisting of (i) wherein said first annular element is a ferromagnetic material and wherein said second annular element is a magnet (ii) wherein said first annular element is a magnet and wherein said second annular element is a ferromagnetic material, (iii) wherein said first annular element is a ferromagnetic material and wherein said second annular element is a Halbach array, (iv) wherein said first annular element is a Halbach array and wherein said second annular element is a ferromagnetic material and (v) wherein said first annular element is a Halbach array and wherein said second annular element is a Halbach array.
3. The apparatus of claim 1 , wherein the net stiffness of each said at least one compression spring is smaller than the effective stiffness of said triplet array.
4. The apparatus of claim 1 , wherein said apparatus is a flywheel based electrostatic (ES) motor/generator.
5. The apparatus of claim 1 , wherein said first annular element is located closer to said first support structure than said first magnetic annular element.
6. A method, comprising:
providing the apparatus of claim 1 ; and
rotating said rotor.
7. An apparatus, comprising:
a vertically oriented open cylindrical rotor having a central axis of rotation and an inner surface;
a supporting first structure that is stationary relative to said rotor, wherein said first structure is located above said rotor;
an annular magnetic first element having its outermost edge attached to a first location of said inner surface of said rotor;
an annular magnetic second element attached to said first support structure, wherein said second element is positioned above, and separated by a gap from, said first element, wherein said first element and said second element are magnetically attracting one to another;
a supporting second structure;
an annular magnetic third element having its outermost edge attached to a second location of said inner surface of said rotor;
an annular magnetic fourth element attached to said second structure;
an annular magnetic fifth element attached to said second structure, wherein said fourth element and said fifth element are positioned on opposite sides of said third element and magnetically repel said third element;
a base and at least one compression spring attached to and located between said second support structure and said base;
a guide tube fixedly attached to said base; and
a guide shaft fixedly attached to said second support structure, wherein said guide tube is configured to receive said guide shaft.
8. An apparatus, comprising:
an open cylindrical rotor having a central axis of rotation and an inner surface;
a first support structure that is stationary relative to said rotor;
a first annular element having its outermost edge attached to a first location of said inner surface of said rotor;
a second annular element attached to said first support structure, wherein said second annular element is positioned in proximity to said first annular element, wherein at least one of said first annular element and said second annular element is configured to magnetically attract the other of said first annular element and said second annular element;
a second support structure;
an axial stabilizer selected from the group consisting of a first triplet array and a second triplet array, wherein said first triplet array comprises:
a first magnetic annular element attached to a second location of said inner surface of said rotor;
a second magnetic annular element attached to said second support structure; and
a third magnetic annular element attached to said second support structure, wherein said second magnetic annular element and said third magnetic annular element are positioned on opposite sides, one to another, of said first magnetic annular element and both magnetically repel said first magnetic annular element, and wherein said second triplet array comprises:
a first magnetic annular element attached to said second structure;
a second magnetic annular element attached to a third location of said inner surface of said rotor;
a third magnetic annular element attached to a fourth location of said inner surface of said rotor, wherein said second magnetic annular element and said third magnetic annular element are positioned on opposite sides of said first magnetic annular element and both magnetically repel said first magnetic annular element;
a base and at least one compression spring attached to and located between said second support structure and said base;
a guide tube fixedly attached to said base; and
a guide shaft fixedly attached to said second support structure, wherein said guide tube is configured to receive said guide shaft.
9. A method, comprising:
providing the apparatus of claim 7 ; and
rotating said rotor.
10. A method, comprising:
providing the apparatus of claim 8 ; and
rotating said rotor.