Bicycle Transmission Axial Shifting Control
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Solution Overview
Problem
Current bicycle transmission systems face challenges in smoothly shifting gears without disrupting the engagement state of the coupling member, leading to inefficient pedaling and potential mechanical stress.
Innovation Solution
A bicycle transmission apparatus comprising a base member, transmission members, coupling members, and a controller that allows for variable speed shifting by controlling the positional relationships and movement timings of these components, ensuring seamless transitions between cogwheels without changing the engagement state of the coupling member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the coupling member is allowed to disengage and re-engage during gear shifting, then the transmission can change gears, but mechanical stress increases and shifting becomes rough
Solution Approach 1:
The transmission member is moved axially in advance to position the cogwheels for engagement before the coupling member arrives, ensuring the coupling member only needs to perform a simple coupling action without disengagement/re-engagement cycles
Solution Approach 2:
The axial movement of the transmission member acts as an intermediary mechanism that facilitates smooth gear transitions by positioning components before the coupling member operates, eliminating the need for the coupling member to disengage and re-engage
2Reliability
If the coupling member maintains continuous engagement during shifting, then mechanical stress is reduced, but the complexity of controlling positional relationships increases
Solution Approach 1:
The patent replaces complex mechanical control mechanisms with a controller that coordinates the timing and positioning of transmission members and guide structures, using electronic control to manage the continuous engagement state
Solution Approach 2:
The system dynamically adjusts the axial positions of transmission members and the timing of their movements to maintain optimal engagement conditions, allowing the coupling member to remain continuously engaged while achieving smooth gear transitions
3Productivity
If gear shifting is performed quickly, then productivity is improved, but the risk of disrupting engagement state and causing mechanical stress increases
Solution Approach 1:
The transmission member is pre-positioned axially before the coupling member arrives at the engagement point, allowing rapid shifting without compromising engagement stability
Solution Approach 2:
The controller coordinates the movements of transmission members and guide structures based on their positional relationships, ensuring that axial positioning and coupling operations are synchronized to maintain engagement state stability during fast shifting
Data Source
AI summary
A bicycle transmission apparatus comprises a base member, a first transmission member, a second transmission member, a first coupling member, a first guide structure, a switching device, and a transmission controller. The switching device is configured to switch a position of the first transmission member relative to the base member in an axial direction between a first axial position and a second axial position. The transmission controller is configured to control the switching device and the first guide structure so as not to change a first engagement state of the first coupling member from one cogwheel to another adjacent cogwheel among first cogwheels when the first transmission member moves relative to the base member in association with a movement of the first guide structure relative to the base member to change a second engagement state of the first coupling member from one cogwheel to another adjacent cogwheel among second cogwheels.