Elliptical Composite Flywheel for High-Speed Energy Storage
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Solution Overview
Problem
Current flywheel energy storage systems are limited by their structural design and material selection, leading to high costs and mass constraints, making them impractical for efficient energy storage due to the need for increased mass and complexity in subsystems, which raises operational and installation costs.
Innovation Solution
A high-speed, compact elliptical ovoid flywheel design utilizing a composite shell formed of helically wound resin-impregnated composite filament material with internal compressive support structures, allowing for increased rotational speed and energy storage capacity while minimizing mass and subsystem complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional mass-focused flywheel designs are used with steel or composite materials, then energy storage capacity increases linearly with mass, but system mass and complexity increase significantly
Solution Approach 1:
The patent changes the fundamental design parameter from mass-focused to speed-focused energy storage. By utilizing the elliptical ovoid shape with helical winding, the flywheel achieves dramatically higher rotational speeds (up to 50,000 RPM) compared to traditional designs. The kinetic energy equation Ek=1/2Iω² shows that increasing angular velocity ω has a squared effect on energy storage, providing exponential rather than linear growth. This parameter transformation resolves the contradiction by achieving higher energy capacity without proportionally increasing mass.
Solution Approach 2:
The patent employs an elliptical ovoid shape with helical winding of composite filaments, replacing traditional flat disk or cylindrical designs. This curved, three-dimensional structure optimizes stress distribution during high-speed rotation and maximizes the moment of inertia per unit mass. The helical winding pattern creates a catenary curve structure that efficiently handles centrifugal forces, enabling the flywheel to operate at extremely high speeds without structural failure, thus achieving high energy density without excessive mass.
2Quantity of substance
If flywheel mass is increased to achieve greater energy storage, then energy capacity improves, but supporting subsystems (bearings, support structure, vacuum enclosure) must be upsized, adding to overall system mass and complexity
Solution Approach 1:
By shifting from mass-based to speed-based energy storage, the patent fundamentally reduces the scale requirements for all supporting subsystems. Magnetic bearings operate more efficiently at higher speeds with lower loads, the vacuum enclosure can be smaller due to reduced mass, and the support structure requires less material. This parameter transformation creates a cascading effect that reduces complexity across the entire system, not just the flywheel itself.
3Quantity of substance
If traditional structural designs are used, then manufacturing and installation are simpler, but energy storage capacity per unit mass is limited
Solution Approach 1:
The patent segments the flywheel structure into modular helical windings of composite filaments impregnated with resin. These segments can be manufactured separately and then assembled by winding around the elliptical ovoid form. This segmentation allows for precise control of material placement, optimization of stress distribution, and simplified manufacturing processes compared to creating a monolithic traditional flywheel structure. The modular approach enables high energy density while maintaining manufacturing feasibility.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The elliptical ovoid flywheel design achieves up to five times higher energy storage capacity per unit mass compared to traditional designs, with improved operational safety and reduced costs, enabling efficient energy storage and release for renewable and traditional power systems.
Implementation Method 1
Flywheels have been well established for over 2000 years as energy storage devices in the form of spinning kinetic energy
Implementation Method 2
The flywheel kinetic energy storage (Ek) capability is governed by the standard equation Ek=1⁄2 I ω{circumflex over ( )}2 where the structural design mass placement in the moment of inertia (I) and the flywheel rotational speed (ω) are the two energy storage drivers
Implementation Method 3
An example high speed, elliptical ovoid flywheel includes a composite shell formed of helically wound ribbons of resin-impregnated composite filament material combined with internal composite structures providing compressive support
Data Source
AI summary
An example flywheel energy storage device includes a fiber-resin composite shell having an elliptical ovoid shape. The example device also includes an axially oriented internal compressive support between the axial walls of the shell. The example device also includes an inner boss plate and an outer boss plate on each side of the shell. The example device also includes a plurality of radially oriented, fiber-resin composite helical wraps forming the shell and coupling the shell to the inner and outer boss plates for co-rotation and torque transfer. The example device also includes boss plate attachments on internal boss plate supports to mount the shell for co-rotation and torque transfer via resin bonding, friction, and compression between the inner and outer boss plates.