Hub Driving Ring Ratchet Geometry for Precise Meshing
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Solution Overview
Problem
Conventional bicycle hub ratchets suffer from poor meshing and increased wear due to inclined surfaces of driving rings interfering, leading to inefficient transmission and wear.
Innovation Solution
A driving ring design with first and second ratchet teeth and engaging teeth, featuring grooves and curved surfaces for precise engagement and self-alignment, combined with an elastic member for unidirectional rotation, enhances the hub device's structural strength and reduces friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the ratchets of the two driving rings are all vertical or pointed, then the structure is simple, but the corners of the inclined surfaces easily interfere and the meshing effect is poor
Solution Approach 1:
The ratchet teeth are segmented into multiple sections along the inclined surface, with each section having a different inclination angle. This segmentation allows the tooth surfaces to contact more flatly and reduces corner interference, improving meshing quality while maintaining structural simplicity
Solution Approach 2:
Different sections of the ratchet teeth have locally optimized inclination angles, where the inclination angle changes along the axial direction. This local quality variation ensures optimal contact between mating surfaces at different positions, enhancing the overall meshing effect
2Stability of the object's composition
If the inclined surfaces of the two driving rings are in contact in the axial direction, then the connection is established, but the transmission effect is poor and wear is considerable
Solution Approach 1:
The inclination angle parameter of the ratchet teeth is changed along the axial direction, creating a gradient profile. This parameter variation optimizes the contact mechanics between mating surfaces, improving transmission efficiency and reducing wear while maintaining stable connection
3Ease of manufacture
If the ratchet teeth are vertical or pointed, then the manufacturing is simple, but the corners easily interfere and meshing is not good
Solution Approach 1:
The ratchet teeth are divided into multiple segments with varying inclination angles, which can be manufactured using standard machining operations. This segmentation approach achieves precise meshing without requiring complex manufacturing processes
Solution Approach 2:
The ratchet teeth incorporate curved surfaces with specific radius of curvature that match the groove geometry. This curvature design ensures precise engagement while maintaining manufacturability through conventional forming processes
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
The design ensures precise engagement and reduced wear, improving transmission efficiency and structural integrity while minimizing operational interference.
Implementation Method 1
an elastic member abutted against and between the hub assembly and the driving assembly so that the plurality of first ratchet teeth and the plurality of second ratchet teeth are axially engaged with each other and unidirectionally rotatable relative to each other
Implementation Method 2
the corners of the inclined surfaces of the two driving rings are easily interfered, and the relatively inclined tooth surfaces cannot be flatly contacted, so that the meshing effect of the ratchets of the two driving rings is not good, thus resulting in poor transmission effect and considerable wear between parts
Data Source
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AI summary
A driving ring (1) is configured to be assembled to and rotatable with a hub assembly (20) and defines an axial direction (11), the drive ring includes an axial direction (12) and a first circumferential side (13) around the axial direction (11), the axial direction (12) includes first ratchet teeth (121) arranged around the axial direction (11) and first grooves (122) extending radially, the first circumferential side (13) includes first engaging teeth (131) arranged around the axial direction (11) and engaged with the hub assembly (20), and between neighboring two of the first ratchet teeth (121) is one of the first grooves (122). A hub device (100) including the driving ring (1) is provided, wherein the hub device (100) further includes a hub assembly (20), a driving assembly (30) an elastic member (40), and a shaft (50) disposed through the hub assembly (20), the driving assembly (30) and the elastic member (40).