Run-flat Device Axial Slices Retaining Belt Rim

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Solution Overview

Problem

Existing run-flat devices for motor vehicle wheels, particularly those with one-piece or multi-block rims, face high manufacturing and assembly costs due to complex geometries and require specific tools for installation, complicating the mounting process.

Innovation Solution

A run-flat device comprising axial slices with reduced thickness, connected without joints, allowing for easy assembly and disassembly, and featuring a retaining belt that can be locked in place without interfering with the tire, enabling efficient handling and mounting without specialized tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex geometries and specific tooling are used for one-piece or multi-block rim devices, then the run-flat support function is improved, but manufacturing and assembly costs increase significantly

Engineering Contradiction:
Improverun-flat support functionVSAvoidmanufacturing and assembly costs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The support ring is divided into multiple axial slices that can be assembled independently around the rim, eliminating the need for complex monolithic geometries and specialized tooling while maintaining structural integrity for run-flat support

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The axial slices are designed with universal features including circumferential grooves for retaining rings and spans for restraining belts that work across different rim types, eliminating the need for rim-specific geometries and reducing manufacturing complexity

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

2Reliability

If specific tooling is used for inserting and locking multi-block rim devices, then the device can be securely installed, but assembly complexity and costs increase

Engineering Contradiction:
Improvedevice installation securityVSAvoidassembly process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The axial slices are designed to be self-assembling using simple elastic retaining rings that snap into circumferential grooves and restraining belts that lock into place through spans, eliminating the need for specialized insertion and locking tools

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Elastic retaining rings and restraining belts serve as intermediary elements that simplify the assembly process by providing foolproof mechanical retention without requiring complex tooling, while still ensuring secure installation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If axial slices with reduced thickness are used, then manufacturing costs are reduced and ventilation is improved, but structural strength may be compromised

Engineering Contradiction:
Improvemanufacturing costVSAvoidstructural strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The axial slices utilize composite construction combining rigid support structures with flexible restraining belts, allowing reduced thickness while maintaining overall structural strength through material synergy

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The circumferential grooves and curved geometries in the axial slices distribute stresses more effectively, allowing thinner sections to achieve the same structural strength as thicker straight sections would require

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Ease of manufacture

If axial slices are connected without joints, then assembly is simplified and manufacturing cost is reduced, but connection reliability between slices may be affected

Engineering Contradiction:
Improveassembly simplicityVSAvoidslice connection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Traditional complex joint assemblies are extracted and replaced with simple circumferential grooves and elastic retaining rings that provide reliable slice connection without requiring elaborate joint structures

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Flexible restraining belts with reversible connection means provide reliable inter-slice connection while accommodating thermal expansion and contraction, maintaining connection reliability without rigid joints

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP3478519B1Run-flat device
Publication Date: 2021.04.21 HUTCHINSON SA
  • EP3478519B1 patent drawingFigure 1~2
  • EP3478519B1 patent drawingFigure 3~5
  • EP3478519B1 patent drawingFigure 4(a)~4(d)

AI summary

A run-flat device (5) for a mounted assembly of a motor vehicle comprising a wheel rim having a rim bottom of diameter D and a tyre mounted on the wheel rim, the run-flat device (5) being suitable for supporting the run-flat tyre and comprising a ring comprising a plurality of axial segments (7) juxtaposed on a circumference of the ring and defining an inner mounting surface (7a) on the rim bottom and an outer support surface (7e) for supporting the run-flat tyre, each segment (7) having at least one bearing (12a) situated radially between the mounting surfaces (7a) and the support surfaces (7e), and at least one belt (9) that encloses the ring around the circumference of same in such a way as to hold it substantially in contact with the rim bottom and that passes through the segments (7), being applied against the bearings (12a) of same, the segments (7) not being articulated with each other and being contiguous or spaced apart from each other on the circumference by a total sum of consecutive spacings, measured between the segments (7) at the mounting surface (7a) of same, that is less than n*D/2.