Wireless Thru-Axle Power Transfer for Bicycle Gear Actuation

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Solution Overview

Problem

Bicycle transmission systems face challenges in efficiently transmitting power and signals to electric components attached to the wheel axle due to weight and space constraints, and existing solutions are cumbersome with robust power and signal supply requirements.

Innovation Solution

A wireless or contactless electric coupling system using a thru-axle with inductive coils for efficient power and signal transfer between the wheel axle and the frame, allowing for detachable and reliable operation without physical contacts, and including energy storage elements for maintaining power and signal integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If electronically actuated actuators are used for gear shifting, then gear shifting can be achieved, but the system becomes cumbersome due to robust power and signal supply requirements

Engineering Contradiction:
Improvegear shifting actuationVSAvoidpower and signal supply system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical cable-actuated gear shifting systems with electronically actuated actuators mounted on the wheel axle. This substitution enables automated gear shifting while the wireless power and signal transmission system eliminates the need for complex mechanical power transmission components, thereby achieving automation without proportional increases in mechanical complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a wireless power and signal transmission system as an intermediary between the battery mounted on the wheel axle and the electronic components. This intermediary enables power and signal supply without physical connections, eliminating the need for robust wired power supply systems while supporting electronically actuated gear shifting

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If electric components are included in or attached to a driven axle, then gear shifting functionality is improved, but weight and space constraints are worsened due to power supply requirements

Engineering Contradiction:
Improvegear shifting functionalityVSAvoidwheel axle assembly
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent merges the battery, wireless power transmission system, and electronic actuator into a single integrated wheel axle assembly. By combining these components and using wireless power transmission, the system eliminates redundant wiring and external power supply components, thereby providing enhanced gear shifting functionality while minimizing additional weight and space

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The battery mounted on the wheel axle serves multiple functions: it powers the electronic actuator for gear shifting, provides wireless power transmission to other components, and can serve as a structural element of the wheel axle assembly. This multi-functionality reduces the need for separate dedicated power supply components, thereby reducing overall weight and space

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If detachable wheel axles are used, then wheel exchange is simplified, but electric connection reliability deteriorates due to potential disconnection of contacts

Engineering Contradiction:
Improvewheel exchangeVSAvoidelectric connection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces mechanical contact-based electric connections with a wireless power and signal transmission system using electromagnetic fields. This substitution eliminates physical contacts that could disconnect due to debris or moisture, ensuring reliable electric connection while maintaining the simplicity of detachable wheel axles for easy wheel exchange

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The wireless transmission system acts as an intermediary that transfers power and signals without requiring physical contact between components. This intermediary enables reliable electric connection for detachable wheel axles by eliminating the dependency on mechanical contacts, allowing wheels to be easily exchanged without concerns about connection reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If wireless transmission is implemented, then power and signal transfer efficiency is improved, but the system complexity increases due to inductive coupling requirements

Engineering Contradiction:
Improvepower and signal transfer efficiencyVSAvoidinductive coupling system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines the wireless power transmission system with the existing wheel axle structure and battery mounting system. By integrating the inductive coupling components into the overall wheel axle assembly design, the system achieves efficient power and signal transfer while minimizing additional complexity through unified component placement and shared structural elements

Inventive Principle:
Principle #5Merging (Combining)

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 efficient and reliable power and signal transfer to electric components on the wheel axle, reducing the need for multiple batteries and simplifying wheel exchange with maintained pairing and charging efficiency, thus enhancing the functionality and usability of bicycle transmission systems.

Implementation Method 1

A wireless or contactless electric coupling system using a thru-axle with inductive coils for efficient power and signal transfer between the wheel axle and the frame

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3615405B1Bicycle transmission wireless actuation system
Publication Date: 2024.12.25 ADVANCING TECH BV
  • EP3615405B1 patent drawingFigure 1~2
  • EP3615405B1 patent drawingFigure 3~4
  • EP3615405B1 patent drawingFigure 5~6

AI summary

The invention relates to a bicycle including a frame (2) with a fork, the fork having dropouts (4) between which a wheel axle (1) is mounted. The wheel axle (1) includes a sensor and/or an electric component (16) arranged to be connected to a control element (29). A detachable electric connection is provided between the sensor and/or electric component (16) and the control element (29). The detachable electric connection includes a short range wireless connection.