Ball-Screw Flywheel Inertia Control for Stable Energy Conversion

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Solution Overview

Problem

Existing flywheels in energy conversion equipment consume significant energy during start-up and fail to effectively manage the conversion of kinetic energy into electrical energy, with fixed moment of inertia leading to instability in rotation.

Innovation Solution

A flywheel device with variable moment of inertia, utilizing a disc-shaped body coupled with ball screw members and masses that adjust their position based on rotation speed, allowing stable operation and efficient energy conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the moment of inertia of the flywheel is fixed, then the structure is simple and easy to manufacture, but the flywheel consumes significant energy during start-up and fails to provide adequate solution for slowing rotation speed during energy conversion

Engineering Contradiction:
Improvestructural simplicityVSAvoidstart-up energy consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent applies the dynamics principle by transforming the fixed moment of inertia into a variable one that changes with rotation speed. The flywheel system includes movable masses that can shift their position relative to the rotation axis, allowing the moment of inertia to be dynamically adjusted. This enables the flywheel to have a smaller moment of inertia during start-up (reducing energy consumption) and a larger moment of inertia during energy conversion (improving efficiency), thus resolving the contradiction between structural simplicity and energy consumption.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If the moment of inertia of the flywheel is fixed, then the manufacturing is easier, but the flywheel cannot effectively manage kinetic energy to electrical energy conversion and maintains unstable rotation

Engineering Contradiction:
Improvemanufacturing easeVSAvoidrotation stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses the dynamics principle to create a variable moment of inertia system that adapts to different operational phases. The movable masses are positioned to increase the moment of inertia during normal operation, providing rotational stability and reliability. During start-up, the masses are repositioned to decrease the moment of inertia, making acceleration easier. This dynamic adjustment resolves the contradiction between manufacturing ease and rotation stability.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the moment of inertia is made variable to improve energy conversion, then energy storage and release efficiency improves, but it becomes challenging for the flywheel to maintain balanced rotation

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoidrotation balance
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by making the moment of inertia variable rather than fixed. The system includes masses that can move radially inward or outward based on operational requirements. During energy conversion, the masses are positioned to maximize the moment of inertia for efficient energy storage. During start-up or speed adjustments, the masses move to optimize acceleration characteristics. This dynamic adjustment resolves the contradiction between energy conversion efficiency and rotation balance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs parameter changes by varying the moment of inertia parameter according to operational needs. The system transitions between different moment of inertia values by moving the masses along the screw shafts. This parameter variation allows the flywheel to optimize performance for different functions: high moment of inertia for energy storage and low moment of inertia for rapid acceleration, thereby resolving the contradiction between energy conversion efficiency and rotation balance.

Inventive Principle:
Principle #35Parameter changes

4Use of energy by moving object

If variable moment of inertia is introduced to reduce start-up energy consumption, then energy efficiency improves, but the device complexity increases due to additional components like ball screw members and masses

Engineering Contradiction:
Improveenergy efficiencyVSAvoidstructural complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by introducing movable masses coupled to screw shafts that can change their radial position. This dynamic configuration allows the moment of inertia to be varied, improving energy efficiency during start-up and operation. Although this increases structural complexity compared to a fixed moment of inertia design, the added complexity is justified by the significant energy savings and performance improvements achieved through variable moment of inertia control.

Inventive Principle:
Principle #15Dynamics

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 flywheel device stabilizes rotation and efficiently converts kinetic energy into electrical energy by varying its moment of inertia, maintaining balanced operation and optimizing energy storage and release.

Implementation Method 1

Each of the ball screw members includes a screw shaft and a pair of ball nuts. The screw shaft is radially pivoted within the disc-shaped body and has a middle section, a left section with forward threads, and a right section with reverse threads.

Methodology Applied
Scientific EffectScrew mechanism: Screw

Implementation Method 2

The spring member is arranged between the masses so that it stretches when the masses move apart and retracts when they come closer together. This helps to stabilize the movement of the masses.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

the flywheel device for an energy converting equipment... converting kinetic energy into electrical energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4636279A1Flywheel device of energy converting equipment
Publication Date: 2025.10.22 CHEN FENG TIEN
  • EP4636279A1 patent drawingFigure 1
  • EP4636279A1 patent drawingFigure 2
  • EP4636279A1 patent drawingFigure 3

AI summary

The flywheel device comprises a disc-shaped body (62), a pair of ball screw members (64), and a pair of masses (63). The ball screw member (64) includes a screw shaft (640) and a pair of ball nuts (642). The screw shaft (640) is received in the disc-shaped body (62) and has a middle section (645), a left section (646) with forward threads, and a right section (647) with reverse threads. One of the ball nuts (642) is screwed to the left section (646) of the screw shaft (640), and the other ball nut (642) is screwed to the right section (647) of the screw shaft (640). One of the masses (63) is coupled to the ball nuts (642) screwed to the left sections (646) of the screw shafts (640), and the other mass (63) is coupled to the ball nuts (642) screwed to the right sections (647) of the screw shafts (640).