Bicycle Hub Freewheel Ratchet Layout for Better Load Distribution
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Solution Overview
Problem
Existing bicycle hub freewheel systems face challenges in stability and durability due to the conventional connection methods of the ratchets, which do not effectively distribute the bearing load and lead to premature wear.
Innovation Solution
The freewheel system increases the diameter of the inner and outer ratchets, connecting them through internal surfaces, allowing the bearings to be positioned farther from the plane of the bicycle, thereby enhancing stability and durability by distributing the load more effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conventional connection method of ratchets is used, then the structure is simple, but the stability and durability are poor due to ineffective load distribution
Solution Approach 1:
The patent transitions from connecting ratchets through external surfaces to connecting through internal surfaces. This dimensional change in the connection interface allows for better load distribution across the ratchet structure, improving stability and durability without significantly increasing overall complexity
Solution Approach 2:
The patent applies different connection approaches to different parts of the ratchet system. Specifically, the inner and outer ratchets are connected through their internal surfaces rather than external surfaces, creating a localized improvement in load distribution and connection quality where it is most needed
2Reliability
If the bearing is positioned close to the bicycle plane, then the structure is compact, but the stability and durability are reduced
Solution Approach 1:
The patent repositions the bearing from the plane of the bicycle to a location farther from this plane, utilizing the radial dimension more effectively. This spatial reconfiguration improves stability and durability by optimizing the bearing's load-bearing position without excessively increasing the overall hub volume
3Reliability
If the diameter of ratchets is increased, then the load distribution is improved, but the device complexity increases
Solution Approach 1:
The patent modifies the diameter parameter of the ratchets, specifically increasing the diameter of the inner and outer ratchets. This parameter change enables better load distribution across the ratchet teeth and connection surfaces, improving reliability while maintaining a relatively simple ratchet mechanism
Data Source
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AI summary
The invention discloses a freewheel system (1) for a bicycle hub (10), comprising an inner ratchet (31) fixed to a hub body (11) and an outer ratchet (21) fixed to a freehub (22). This system (1) is particular in that an internal surface of the inner ratchet (31) is coupled to an external surface of a connection shell (34) joined to the body (11), where a diameter of the internal surface of the connection shell (34) is larger than a diameter of a bearing (RC2) connecting the hub body (11) and the axle (E). Similarly, also the coupling between the outer ratchet (21) and the freehub (22) can be carried out by the interaction between the internal surface of the outer ratchet (21) and the external surface of the freehub (22). The invention is also directed to an inner ratchet (31) and to an outer ratchet (21).