Clamped E-Bike Chainring Assembly to Prevent Shaft Wobble
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Solution Overview
Problem
Existing e-bike chainring assemblies face issues with secure attachment to motor output shafts, leading to potential wobbling and wear during operation, and require tools that may damage the shaft for removal, complicating maintenance.
Innovation Solution
A chainring assembly with a circumferential ring and radial slot design that clamps onto the motor output shaft using a fastener, ensuring axial and radial security and easy removal without damaging the shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional chainring assembly is attached to the motor output shaft, then the chainring can transmit power, but the attachment becomes loose causing wobble and wear during operation
Solution Approach 1:
The clamp assembly incorporates a adjustable clamping mechanism that can dynamically adapt to different shaft diameters and maintain optimal clamping force during operation. The radial arms can flex slightly to accommodate manufacturing tolerances while maintaining secure attachment, preventing both looseness and excessive stress concentration.
Solution Approach 2:
The clamping force and radial position of the clamp assembly can be adjusted to optimize the attachment. By changing the clamping parameter (force applied) and radial position, the system achieves secure attachment without causing damage to the shaft, resolving the contradiction between attachment security and stability.
2Ease of repair
If tools are used to remove the chainring assembly, then the chainring can be detached, but the shaft may be damaged during removal
Solution Approach 1:
The clamp assembly incorporates a built-in release mechanism that acts as an intermediary between the user and the attachment. This mechanism allows for tool-free or minimal-tool removal by engaging with corresponding features on the motor output shaft, eliminating the need for external tools that could damage the shaft during removal.
Solution Approach 2:
The attachment mechanism is segmented into discrete components (radial arms, clamping elements, release mechanism) that can be independently manipulated. This segmentation allows for easy disassembly without requiring forceful tool application to the shaft, thereby preventing shaft damage while enabling easy removal.
3Stability of the object's composition
If the chainring assembly is tightly secured to prevent wobble, then operational stability improves, but removal and maintenance become difficult
Solution Approach 1:
The clamp assembly uses a dynamic clamping system that provides strong holding force during operation but allows for easy release when needed. The mechanism transitions from a tightly secured state during operation to an easily removable state during maintenance, resolving the contradiction between operational stability and maintenance ease.
Data Source
AI summary
An electric bicycle includes a frame assembly, wheels supporting the frame assembly, a motor assembly coupled to the frame assembly and having a motor output shaft, and a chainring assembly including a mounting portion clamped onto the motor output shaft.