Hub Motor Axle Sleeve Structure for Easy E-Bike Wheel Disassembly

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Solution Overview

Problem

Existing hub motors on electric-assisted bicycles require specialized tools for disassembly and assembly, making maintenance inconvenient.

Innovation Solution

A hub motor design featuring an independent cassette flywheel outside the end cover, a limiting sleeve, and an anti-rotation piece, allowing easy disassembly by loosening the axle rod and removing the limiting sleeve, facilitating maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wheel is fixed securely to the bicycle frame using traditional hub motor mounting methods, then the structural stability and reliability are improved, but the ease of disassembly and maintenance deteriorates due to requiring special tools

Engineering Contradiction:
Improvestructural stabilityVSAvoidease of disassembly
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The mounting system is divided into separate components: the axle rod with fork ends, the axle sleeve, and removable fastening elements (limiting sleeve and anti-rotation piece). This segmentation allows the wheel assembly to be securely mounted while enabling easy disassembly by simply removing these separate fastening components without requiring special tools.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fastening function is extracted from the traditional integrated hub motor structure and implemented through separate, removable components (limiting sleeve and anti-rotation piece). These extracted elements can be easily removed to facilitate wheel disassembly for maintenance, while still providing secure mounting during normal operation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If the cassette flywheel is integrated inside the end cover of the hub motor, then the structural compactness is improved, but the ease of maintenance and part replacement deteriorates

Engineering Contradiction:
Improvestructural compactnessVSAvoidease of part replacement
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The cassette flywheel is separated from the end cover structure and mounted independently on the axle sleeve. This segmentation allows the cassette flywheel to be accessed and replaced by simply removing the limiting sleeve, without requiring disassembly of the end cover or other complex operations, thus improving maintenance ease while maintaining a relatively compact overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cassette flywheel is extracted from the traditional enclosed position inside the end cover and relocated to an independent position on the axle sleeve. This extraction enables easy access and replacement of the cassette flywheel by removing only the limiting sleeve, significantly improving maintenance convenience while keeping the structure compact.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If simple fastening methods are used to allow easy disassembly, then the ease of operation is improved, but the reliability and anti-rotation capability deteriorates

Engineering Contradiction:
Improveease of disassemblyVSAvoidanti-rotation capability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The anti-rotation and fastening functions are divided into separate simple components: the limiting sleeve prevents axial displacement and the anti-rotation piece prevents rotation. These segmented, simple components are easy to install and remove, providing both ease of operation and reliable functional performance without requiring complex mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The anti-rotation function is extracted as a separate dedicated component (anti-rotation piece with anti-rotation head) rather than being integrated into a complex fastening mechanism. This extracted anti-rotation piece works in conjunction with the simple limiting sleeve to provide reliable anti-rotation capability while maintaining ease of disassembly through simple component removal.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4124557B1Electric assisted bicycle and hub motor thereof
Publication Date: 2025.07.30 LINGBEI MOTOR TECH (SHANGHAI) CO LTD
  • EP4124557B1 patent drawingFigure 1~2
  • EP4124557B1 patent drawingFigure 3
  • EP4124557B1 patent drawingFigure 4~5

AI summary

A hub motor is disclosed, the hub motor is mounted on an axle assembly, the an axle assembly includes an axle rod and an axle sleeve, and an independent cassette flywheel is provided at one end of the axle sleeve where an end cover is located, a limiting sleeve is disposed outside of the cassette flywheel to prevent the cassette flywheel from detaching from the axle sleeve, and an anti-rotation piece for preventing rotation of the axle sleeve is provided at another end of the axle sleeve where a wheel hub is located.