Self-Powered Bicycle Derailleur With Chain-Driven Generator
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Solution Overview
Problem
Bicycle derailleurs with battery-powered motors require frequent charging or battery replacement, which can be inconvenient, especially in remote locations, and existing systems lack a reliable power source during shifting.
Innovation Solution
A bicycle derailleur with an integrated electrical generator system that harnesses energy from the chain movement to power a motor, featuring a generator coupled to a cage assembly and a clutch mechanism to activate/deactivate power generation based on chain direction, with an optional energy storage device for backup power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a battery-powered motor is integrated into the derailleur, then the derailleur can be electrically actuated for precise shifting control, but the battery requires frequent charging or replacement which is inconvenient especially in remote locations
Solution Approach 1:
The system harvests energy from the bicycle's own chain movement through the generator to charge the battery, making the power supply self-sustaining without external charging infrastructure. The generator is driven by the chain during normal bicycle operation, automatically recharging the battery while the bike is in use.
Solution Approach 2:
The patent combines the generator, battery, and motor into an integrated drivetrain system where the generator and motor share the same axis, eliminating the need for separate power supply systems and reducing overall complexity.
2Use of energy by moving object
If a generator is integrated into the derailleur to harvest energy from chain movement, then the battery can be charged during use, but the system complexity increases with additional components
Solution Approach 1:
The generator and motor are positioned coaxially and share common mounting structures, reducing the number of separate components and simplifying the overall system architecture while enabling energy harvesting.
Solution Approach 2:
The chain serves multiple functions: it drives the bicycle rear wheel for propulsion and simultaneously drives the generator through the cage assembly to charge the battery, eliminating the need for a separate energy input system.
3Ease of repair
If the cage assembly is made replaceable for easy maintenance, then the motor and generator can be easily replaced, but complex couplings between moving parts must be avoided
Solution Approach 1:
The derailleur is divided into distinct modular components: a stationary base member and a moveable cage assembly that can be independently replaced. The cage assembly contains the motor, generator, and chain pulley as an integrated unit that simplifies maintenance.
Solution Approach 2:
A coupling assembly with coupling members connects the cage assembly to the base member, providing a standardized interface that simplifies installation and removal while accommodating the moving parts within the cage assembly.
4Loss of energy
If a clutch mechanism is added to activate/deactivate power generation based on chain direction, then energy can be harvested only during forward pedaling, but the device complexity increases
Solution Approach 1:
The clutch mechanism dynamically engages and disengages the generator based on the direction of chain movement, allowing energy harvesting during forward pedaling while preventing energy loss during backward pedaling or coasting, optimizing overall system efficiency.
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
Ensures continuous power supply for the motor and other accessories, allows easy replacement of the cage assembly, and eliminates the need for complex couplings between moving parts, providing reliable operation and convenience.
Implementation Method 1
An electrical generator system may be coupled to and moveable with the cage assembly. The electrical generator system may include a generator and a generator drive system.
Implementation Method 2
The clutch may driveably connect the chain pulley and the generator when the chain pulley is rotated in the first rotational direction such that the generator is activated. The clutch disconnects the chain pulley and the generator when the chain pulley is rotated in the second rotational direction.
Data Source
Figure 1
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AI summary
A bicycle derailleur includes a base member mountable to a bicycle frame and a cage assembly moveably coupled to the base member. One or both of a motor and/or electrical generator system may be coupled to and moveable with the cage assembly. The motor is operable to move the cage assembly. The electrical generator system includes a generator and a generator drive system. An energy storage device, spaced apart from the cage assembly, may be connected to the electrical generator system and/or motor with a flexible electrical conductor.