Bicycle Clutch Assembly for Gear Shifting Under Load
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Solution Overview
Problem
Current transmission units for human-powered vehicles, such as bicycles, face challenges in shifting gears under load due to high frictional forces that prevent disengagement of gears, especially when high torques are transmitted, making it difficult to change gears without dropping tractive force, particularly on inclines.
Innovation Solution
A clutch arrangement with a two-part blocking body arrangement that allows for easy coupling and disengagement, featuring a locking body carrier and member pivotally connected, enabling force transmission while minimizing frictional engagement and allowing for shifting under load by pivoting the blocking body arrangement into a release position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional clutch arrangement is used in transmission units for human-powered vehicles, then gear shifting can be achieved, but high frictional forces prevent disengagement under load, especially when high torques are transmitted
Solution Approach 1:
The blocking body arrangement is divided into two separately pivotable parts: a blocking body carrier pivotably mounted on the second rotary member, and a blocking body member pivotably mounted on the carrier. This segmentation allows independent movement of each component, enabling one part to be disengaged without requiring simultaneous disengagement of the other, thereby reducing the overall frictional force barrier during gear shifts under load
Solution Approach 2:
Both the blocking body carrier and blocking body member are designed with pivotable connections rather than fixed mounts. The carrier pivots on the second rotary member about a first pivot axis, while the member pivots on the carrier about a second pivot axis. This dynamic configuration allows the blocking body arrangement to adapt its position during operation, facilitating easier disengagement under varying load conditions by changing the geometric relationship between components
2Power
If high torques are transmitted through the clutch arrangement, then power transmission efficiency is improved, but gear disengagement becomes difficult due to increased frictional forces
Solution Approach 1:
By segmenting the blocking body arrangement into two independently pivotable components (carrier and member), the system allows power to be transmitted through one component while the other can be disengaged. The blocking body member can be pivoted out of engagement with the clutch teeth while the carrier remains engaged, enabling gear changes under high torque conditions without requiring complete disengagement of the entire blocking body arrangement
Solution Approach 2:
The blocking body carrier acts as an intermediary between the second rotary member and the blocking body member. It receives and transmits forces from the second rotary member while providing a pivotable connection for the blocking body member. This intermediary structure allows the member to be disengaged from clutch teeth under load by pivoting relative to the carrier, which remains firmly connected to the power transmission path
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 smooth gear shifting under load conditions, reducing frictional forces and allowing for efficient power transmission without gear disengagement issues, even when high forces are transmitted, thus maintaining tractive force and improving riding dynamics.
Implementation Method 1
a locking body carrier which is pivotably mounted on the second rotary member and on which a locking body member can be pivotally mounted
Data Source
Figure 1~2
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AI summary
Clutch arrangement (100) for coupling members (88, 26), in particular as a gear shifting clutch in a gear mechanism unit (10), with a first member (88) which has a clutch toothing system (94), with a second member (26), on which at least one locking body arrangement (90) is mounted pivotably, wherein the locking body arrangement (90) can be pivoted into a clutch position (KP), in the case of which a driving section (138) of the locking body arrangement (90) engages into the clutch toothing system (94), in order to couple the first member to the second member in a positively locking manner with respect to a relative movement in a first direction, and wherein the locking body arrangement (90) can be pivoted into a release position (FP), in the case of which the driving section (138) of the locking body arrangement (90) does not engage into the clutch toothing system (94). Here, the locking body arrangement (90) has a locking body carrier (110) which is mounted pivotably on the second member (26), and has a locking body member (116) which is mounted pivotably on the locking body carrier (110) and on which the driving section (138) is configured.