Composite Flywheel Rotor with Variable Fiber Winding Angles
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Solution Overview
Problem
Current composite flywheels require precise balancing and fail prematurely due to manufacturing flaws, limiting their maximum sustainable rotational speed and energy storage capacity, while being expensive and restricted in size.
Innovation Solution
A composite annular rotor with fibers embedded in a matrix, wound at varying angles and composed of multiple chemical classes, is designed to operate near the ultimate tensile strength of the fibers, eliminating the need for balancing and allowing for larger sizes, using a thermoplastic or thermoset polymer matrix with fiberglass or carbon fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional composite flywheels are used, then energy storage capacity can be improved by increasing rotational speed, but manufacturing flaws cause premature failure before ultimate tensile strength is reached
Solution Approach 1:
The patent applies local quality by varying the fiber winding angle throughout the rotor structure. Fibers are wound at different angles in different regions to optimize stress distribution and utilize the ultimate tensile strength of fibers more completely. This localized optimization allows the structure to achieve higher reliability and sustain higher rotational speeds without premature failure from manufacturing flaws.
Solution Approach 2:
The patent employs composite materials with fibers embedded in a matrix, where fibers provide tensile strength and the matrix provides structural continuity and damage tolerance. This composite structure allows the flywheel to operate closer to the ultimate tensile strength of the fibers while maintaining reliability, as the matrix distributes stresses and prevents catastrophic failure from localized manufacturing flaws.
2Stability of the object's composition
If composite flywheels require precise balancing, then operational stability can be improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies segmentation by constructing the rotor from multiple discrete winding layers with different fiber angles. This segmented approach to construction inherently balances the structure, as each layer can be designed to counterbalance others, eliminating the need for post-manufacturing precision balancing while maintaining operational stability.
Solution Approach 2:
The patent changes the fiber winding angle parameter throughout the structure to optimize both stability and reduce balancing requirements. By strategically varying fiber angles in different regions, the structure achieves inherent balance, eliminating complex balancing procedures while maintaining operational stability at high rotational speeds.
3Use of energy by moving object
If rotational speed is increased to improve energy density, then weight energy density improves, but centrifugal force causes conventional materials to disintegrate
Solution Approach 1:
The patent uses composite materials where high-strength fibers embedded in a matrix can withstand the centrifugal forces generated at high rotational speeds. The fiber-matrix composite structure provides the necessary strength-to-density ratio to maintain material integrity at speeds where conventional materials would disintegrate, enabling high weight energy density.
Solution Approach 2:
The patent applies local quality by orienting fibers at specific angles in different regions of the rotor to resist centrifugal forces where they occur most intensely. This localized fiber orientation optimization allows the structure to sustain higher rotational speeds without material failure, thereby achieving higher weight energy density.
4Quantity of substance
If composite flywheels are made larger to improve energy storage, then energy capacity increases, but manufacturing issues limit current size
Solution Approach 1:
The patent applies segmentation by constructing the rotor from multiple discrete winding layers that can be manufactured and assembled in a modular fashion. This segmented construction approach enables larger flywheel sizes to be manufactured by assembling multiple sections, overcoming the manufacturing limitations that restrict current flywheel sizes while increasing total energy storage capacity.
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 solution enables high-speed operation without balancing, increases energy storage capacity, and enhances the structural integrity of flywheels, allowing for larger sizes and higher rotational speeds while reducing manufacturing issues and material costs.
Implementation Method 1
At very high rotational speeds, centrifugal force suffices to cause these materials to literally fly apart, disintegrate
Implementation Method 2
operate near the ultimate tensile strength of the fibers
Implementation Method 3
composites tend to unravel rather than disintegrate into shrapnel-like shards. Thus, composite flywheels are much more containable in case of failure
Implementation Method 4
A key property of flywheels is the amount of kinetic energy that can be contained therein. This is given by the formula W=1⁄2Iω2 where W represents kinetic energy, I is the moment of inertia of the mass of the flywheel around the center of rotation and ω is the angular velocity
Data Source
AI summary
The invention herein relates to a flywheel capable of high speed rotational operation in excess of 15,000 rpm, the flywheel comprising a composite rotor having a polymeric matrix in which are embedded fibers helically wound at an initial angle with respect to the axis of rotation of the rotor of from about 50° to about 80° and increasing in a stepwise or continuous manner to about 90°.