Adjustable Freewheel Hub Assembly for Switchable Bicycle Drive Modes
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Solution Overview
Problem
Conventional freewheel hub assemblies are inconvenient for detachment and replacement, leading to high purchasing costs due to the need for different types of bicycles to satisfy varying functions, and often result in a smaller gear ratio and slower performance.
Innovation Solution
An adjustable freewheel hub assembly with a hub component, coaster brake mechanism, and adjusting switches that allow for synchronous rotation of the helix hub driver and sprocket, enabling conversion between fixed-gear, single-speed, and coaster brake modes, and a smaller sprocket design for increased gear ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a conventional freewheel hub assembly uses an inner shell between the sprocket outer shell and helix hub driver, then the sprocket has a larger diameter, but the gear ratio of the chainring to the sprocket becomes smaller and the bike becomes slower
Solution Approach 1:
The patent removes the inner shell component that was previously positioned between the sprocket outer shell and helix hub driver. This extraction eliminates the space-consuming element, allowing the sprocket to have a smaller diameter while maintaining proper engagement, thereby increasing the gear ratio and bike speed
2Adaptability or versatility
If different types of bicycles are purchased to satisfy different functions, then various functions are achieved, but the purchasing cost increases
Solution Approach 1:
The patent designs a universal freewheel hub assembly that can perform multiple functions (coaster brake, fixed gear, single speed) through a single adjustable mechanism. The adjusting switch allows the hub assembly to be reconfigured for different riding modes, eliminating the need to purchase multiple specialized bicycles and thereby reducing overall purchasing cost
3Reliability
If a conventional freewheel hub assembly is designed for specific functions, then the function is reliable, but the detachment and replacement become inconvenient
Solution Approach 1:
The patent divides the freewheel hub assembly into separable components including the adjusting switch, pawls, and spring mechanism. This segmentation allows individual parts to be easily detached, adjusted, or replaced without affecting the entire hub assembly, improving maintenance convenience while maintaining functional reliability through proper reassembly of the modular components
Data Source
AI summary
An adjustable freewheel hub assembly has a hub component, a coaster brake mechanism, and an adjusting switch. The hub component has an axle, a hub shell, a helix hub driver, and a sprocket. The helix hub driver has a pawl groove and a first engaging notch formed on its periphery. The sprocket is sheathed onto the helix hub driver, is hollow, and has a ratchet teeth construction formed on an inner wall of the sprocket and a second engaging notch. The coaster brake mechanism is disposed in the hub shell and is drivable by the helix hub driver. By the adjusting switch engaged in or detached from the first engaging notch and the second engaging notch, the freewheel hub assembly can be adjusted between a fixed-gear mode and a single-speed mode to have different functions.