Motorized Bicycle Derailleur Anti-Jamming Spring and Controller
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Solution Overview
Problem
Existing motorized bicycle derailleurs suffer from a mismatch between the motor's range of movement and the chain guide's range between top and low gear positions, leading to overcurrent issues and reduced motor life, as well as wastage of electrical power.
Innovation Solution
A motorized bicycle derailleur assembly with a motor unit, a movable part, and a controller, where the motor unit has a prescribed maximum movement range, and an anti-jamming spring is used to compress when the motor continues to apply force beyond the lockup position, with the controller setting the motor unit's output stroke to match the mechanical stroke of the chain guide, ensuring the anti-jamming bias remains uncompressed during normal shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the motor unit is designed with a large range of movement to ensure complete gear shifting, then the chain guide can reach all gear positions, but the motor exceeds its optimal movement range causing overcurrent and reduced motor life
Solution Approach 1:
A linkage mechanism acts as an intermediary between the motor unit and the chain guide. The linkage converts the motor's rotational movement into linear movement of the chain guide, allowing the motor to operate within its optimal range while the chain guide achieves the full required range of movement through mechanical advantage and motion transformation.
Solution Approach 2:
The system changes the movement parameters by using a linkage mechanism that transforms the motor's rotational displacement into linear displacement of the chain guide. This parameter transformation allows the motor to rotate through a limited angle while the chain guide traverses the full distance needed for complete gear shifting.
2Adaptability or versatility
If the motor unit operates with a range of movement larger than needed, then all gear positions can be reached, but electrical power is wasted due to overcurrent
Solution Approach 1:
The linkage mechanism serves as an intermediary that allows the motor to operate within its optimal movement range while still achieving complete gear shifting. By transforming motor rotation into chain guide linear movement, the system avoids excessive motor movement that would cause overcurrent and energy waste.
Solution Approach 2:
The motor is designed to perform slightly more movement than strictly necessary, but the linkage mechanism ensures that this excess movement does not result in overcurrent conditions. The mechanical system absorbs the extra movement capacity without translating it into harmful electrical stress on the motor.
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
This solution ensures the motor unit's output stroke matches the chain guide's movement range, preventing overcurrent and extending motor life while maintaining efficient shifting, thus enhancing the durability and adjustability of the derailleur assembly.
Implementation Method 1
The anti-jamming spring is configured and arranged to compress when the motor unit continues to apply a moving force to the movable part after the movable part reaches a lockup position
Data Source
AI summary
A motorized bicycle derailleur assembly has a motor unit, a movable part (e.g., a motor linkage, a derailleur linkage and/or a chain guide) and a controller. The movable part is in response to activation of the motor unit within a mechanical stroke. The motor unit has a motor output stroke with a prescribed maximum movement range that is larger than the mechanical stroke of the movable part. The movable part has an anti-jamming arrangement having an anti-jamming spring. The anti-jamming spring is configured and arranged to compress when the motor unit continues to apply a moving force to the movable part after the movable part reaches a lockup position. The controller is configured to set the motor unit output stroke to an operating movement range that is smaller than the prescribed maximum movement range so that the anti-jamming biasing element remains uncompressed during normal shifting operation.