Automatic Flywheel Starting With Speed-Responsive Drag Torque

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Solution Overview

Problem

Existing flywheels, especially those used in large square balers, face difficulties in starting due to high inertia requirements, which lead to complex dual-mass flywheel structures and inefficiencies when using internal combustion engines with limited starting torque.

Innovation Solution

A flywheel with an automatic starting device that utilizes a drag torque transmission member to gradually accelerate the flywheel mass through friction, reducing the need for high starting torque and simplifying the structure by using radially movable masses and a hub to modulate friction force based on centrifugal force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the flywheel inertia is increased to regularize operation and overcome thrust peaks, then the operation regularity improves, but the starting phase becomes more difficult and longer

Engineering Contradiction:
Improveoperation regularityVSAvoidstarting phase
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The flywheel is divided into two separate masses (first flywheel mass and second flywheel mass) that can rotate independently during the starting phase. This segmentation allows the system to achieve both high total inertia for operation regularization and reduced starting difficulty, as each mass can be accelerated separately rather than requiring simultaneous acceleration of the entire flywheel inertia.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a dual-mass flywheel is used to overcome starting difficulties, then the starting phase becomes easier, but the structure becomes more complex

Engineering Contradiction:
Improvestarting phaseVSAvoidflywheel structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A drag torque transmission member is introduced as an intermediary element between the drive shaft and the second flywheel mass. This member automatically transmits torque during the starting phase and disengages when the flywheel reaches operating speed, providing the benefits of dual-mass flywheels without requiring complex hydraulic controls or additional actuation systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If an automatic starting device with drag torque transmission is used, then the starting torque requirement is reduced, but the device complexity increases

Engineering Contradiction:
Improvestarting torqueVSAvoidstarting device structure
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The drag torque transmission member is designed to automatically engage and disengage based on the rotational speed differential between the drive shaft and the second flywheel mass. During starting, it automatically transmits torque; once the flywheel reaches operating speed, it automatically disengages without requiring external control systems, sensors, or actuators, thereby reducing device complexity while maintaining reduced starting torque requirements.

Inventive Principle:
Principle #25Self-service

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

Enables smooth start-up of machines with limited starting torque without overloading the power source, reducing the risk of engine shutdown and simplifying the flywheel design, allowing for efficient power transmission to variable loads.

Implementation Method 1

a drag torque transmission member for transmitting a drag torque from the automatic starting device to the flywheel mass

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The friction torque is a function of the centrifugal force that, due to the rotation of a drive shaft, acts on radially movable masses

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3805600B1Automatic starting flywheel
Publication Date: 2024.12.18 LUSETTI LEA
  • EP3805600B1 patent drawingFigure 1
  • EP3805600B1 patent drawingFigure 2
  • EP3805600B1 patent drawingFigure 3~7

AI summary

The flywheel (3) comprises a flywheel mass (5) and an automatic starting device (9) for driving into rotation the flywheel mass (5), coaxial with the flywheel mass (5), rotatable with respect to the flywheel mass, and adapted to be torsionally coupled to a motion input (7). The automatic starting device (9) comprises a drag torque transmission member for transmitting drag torque from the automatic starting device (9) to the flywheel mass (5), adapted to transmit a torque that increases as the angular speed of the automatic starting device increases.