Motorized Rear Derailleur Dynamo Power Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bicycles equipped with electrically controlled shifting systems require a constant electrical power source, which can be inconvenient and may lead to energy depletion, especially when not in use.
Innovation Solution
A motorized rear derailleur system that incorporates a dynamo-powered pulley arrangement to generate electrical energy, coupled with a power limit circuit and electrical storage unit, allowing the system to operate autonomously and efficiently manage energy supply to the motor unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a battery is provided as a power source for electrical components, then the bicycle can operate electrical components, but the battery requires periodic replacement or recharging which is inconvenient
Solution Approach 1:
The system generates its own electrical energy through the dynamo integrated into the pulley arrangement, which converts mechanical energy from the bicycle's motion into electrical energy. This self-generating capability eliminates the need for external battery replacement or recharging, allowing the system to operate indefinitely as long as the bicycle is in motion.
2Use of energy by moving object
If a wheel hub generator is provided as a power source, then the bicycle can generate electrical energy, but the generated energy may be insufficient during low-velocity periods
Solution Approach 1:
The electrical storage unit accumulates electrical energy generated during high-velocity periods when the dynamo produces sufficient power. This stored energy is then available to supplement or replace dynamo generation during low-velocity periods, ensuring continuous and reliable power supply regardless of riding conditions.
3Speed
If the motor control circuit remains continuously active to respond to shifting commands, then the gear shift system responds immediately, but energy is consumed even when no shifting is needed
Solution Approach 1:
The motor control circuit operates in periodic cycles rather than continuously. The sleep mode control circuit monitors for activity and periodically activates the motor control circuit when needed (upon detecting a velocity signal indicating shifting command) and deactivates it during idle periods. This periodic operation maintains responsiveness to genuine shifting commands while minimizing energy consumption during normal riding.
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 the bicycle to generate and store electrical energy, ensuring continuous operation of the gear shift system, reducing the need for external power sources and optimizing energy usage through a sleep mode control mechanism.
Implementation Method 1
The pulley arrangement includes a pulley having a dynamo that generates electrical energy in response to rotation of the pulley
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A motorized rear derailleur is basically provided with a base member, a movable member, a pulley arrangement, a motor unit and a power limit circuit. The movable member is movably mounted to the base member between a plurality of gear positions. The pulley arrangement is supported by the movable member. The pulley arrangement includes a pulley having a dynamo that generates electrical energy in response to rotation of the pulley. The motor unit is operatively coupled between the base member and the movable member to selectively move the movable member relative to the base member between the gear positions. The motor unit is electrically coupled to the dynamo to selectively receive electrical energy generated by the dynamo. The power limit circuit is electrically coupled between the dynamo and the motor unit.