Sprocket Support Structure with Projections for Interchangeable Cassettes

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Solution Overview

Problem

Existing bicycle hub assemblies do not allow for the interchangeable installation of sprocket cassettes with differing numbers and combinations of sprockets without modification to the hub assembly.

Innovation Solution

A sprocket support structure featuring a main body with projections and an abutment ring that can interchangeably support various sprocket cassettes, utilizing projections and abutment ring surfaces to secure and position sprocket cassettes with varying numbers and combinations of sprockets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional hub assembly structure is used, then the structure is simple and easy to manufacture, but it does not allow for interchangeable installation of sprocket cassettes with differing numbers and combinations of sprockets

Engineering Contradiction:
Improveinterchangeability of sprocket cassettesVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hub assembly is segmented into distinct functional components: a main body, multiple projections extending from the main body, and an abutment ring. This segmentation allows each component to serve a specific function while enabling the overall structure to accommodate various sprocket cassette configurations through modular engagement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The main body with its plurality of projections and the abutment ring create a universal mounting interface that can accommodate multiple types of sprocket cassettes. The projections provide standardized engagement points that work with different sprocket configurations, making the hub assembly versatile for interchangeable installations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the hub assembly is designed to accommodate multiple sprocket configurations, then adaptability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvecompatibility with different sprocket cassettesVSAvoidmanufacturing difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

By dividing the hub assembly into a main body and a separate abutment ring, the design allows for standardized mass production of each component. The segmented structure enables simplified manufacturing processes while maintaining the capability to accommodate multiple sprocket cassette types through the standardized projection interface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design uses parameter changes in the projections (varying distances D1 and D2 from the outer surface to the outermost surfaces) to accommodate different sprocket configurations. This allows a single hub assembly design to adapt to multiple sprocket types by utilizing geometric parameter variations rather than requiring multiple specialized components.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If projections with varying distances are used to accommodate different sprocket cassettes, then interchangeability is enabled, but the precision requirements for manufacturing increase

Engineering Contradiction:
Improveaccommodation of different sprocket configurationsVSAvoidprecision of projection distances
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The design deliberately incorporates parameter changes in the projection geometry, specifically the distances D1 and D2 from the outer surface to the outermost surfaces. These controlled parameter variations enable the hub assembly to accommodate different sprocket cassette configurations while maintaining manufacturability through standardized tolerance ranges.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Different regions of the projections have different geometric properties (varying distances D1 and D2), creating local quality variations that are optimized for specific sprocket configurations. This allows the same component to provide different engagement characteristics at different locations, enabling versatility without requiring multiple specialized parts.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2452865B2Sprocket support structure
Publication Date: 2025.07.16 SHIMANO INC
  • EP2452865B2 patent drawingFigure 1
  • EP2452865B2 patent drawingFigure 2
  • EP2452865B2 patent drawingFigure 3

AI summary

A sprocket support structure includes a main body, a plurality of projections and an abutment ring. The main body includes an outer surface with a plurality of parallel extending sprocket attachment splines defining a plurality of sprocket engaging grooves between the sprocket attachment splines. The projections extend radially outward farther than the sprocket attachment splines with respect to a rotation axis of the main body. Each of the projections includes a first surface facing in a first axial direction of the main body. The abutment ring is disposed on the main body as a separate member from the main body. The abutment ring includes a second surface facing in the first axial direction and axially spaced from the first surfaces of the projections with respect to the rotation axis. The second surface of the abutment ring is exposed between the projections as viewed along the sprocket engaging grooves.