Multi-Part Bicycle Sprocket With Covered Fasteners and Low Weight
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bicycle sprockets face challenges in balancing weight reduction and improved appearance while maintaining effective chain-holding performance and torque transmission.
Innovation Solution
The bicycle sprocket design incorporates a sprocket body with radially extending teeth, a mounting member with hub and mounting arms, and a cover member made of non-metallic materials, featuring internal and external threaded portions for weight savings and enhanced support, along with a torque transmitting profile for efficient pedaling torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the sprocket uses a traditional solid metal construction, then strength and durability are improved, but weight increases
Solution Approach 1:
The sprocket is divided into multiple components: a metal sprocket body containing threaded portions, separate fastening members with shafts and heads, and a cover member. This segmentation allows the metal portions to provide strength while non-metallic portions reduce weight.
Solution Approach 2:
The sprocket combines metallic materials (sprocket body, fastening members) with non-metallic materials (cover member made of resin or plastic). This composite construction achieves optimal balance between strength from metal components and weight reduction from the non-metallic cover.
2Ease of manufacture
If the sprocket uses exposed fastening members, then assembly is simplified, but appearance deteriorates
Solution Approach 1:
The cover member acts as an intermediary component that conceals the fastening members and threaded portions while allowing them to function. The cover is made of non-metallic material and can be molded with aesthetic designs, improving appearance without interfering with the mechanical fastening function.
3Volume of moving object
If the sprocket uses a compact design, then space efficiency is improved, but chain-holding performance deteriorates
Solution Approach 1:
The sprocket teeth are designed with specific local geometric features including tooth depth, thickness variations, and profile shapes optimized for chain engagement. These localized quality enhancements ensure reliable chain holding while the overall sprocket maintains a compact form factor suitable for modern bicycle frames.
Data Source
AI summary
A bicycle sprocket comprises a sprocket body, a plurality of sprocket teeth, a mounting member, at least one fastening member, and a cover member. The sprocket body has at least one first threaded portion. The mounting member has at least one fastening hole configured to be aligned with the at least one first threaded portion in the assembled state. The at least one fastening member has a fastening shaft portion, a fastening head portion, and a second threaded portion. The second threaded portion is configured to threadedly engage with the at least one first threaded portion of the sprocket body in the assembled state. The cover member is configured to at least cover the fastening shaft portion of the at least one fastening member when viewed from an axial direction with respect to the rotational center axis in the assembled state.