Laterally-Contoured Road Wheel for Tire Testing

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Solution Overview

Problem

Tires tested on cylindrical road wheels exhibit uneven wear distribution and footprint differences compared to real-world flat surfaces, making it challenging to replicate real-world conditions for accurate tire performance evaluation.

Innovation Solution

A road wheel with a laterally-contoured tire operating surface that extends laterally along a contoured path, mimicking a flat surface, to improve tread wear distribution and footprint similarity to those obtained on a flat surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a cylindrical outer tire operating surface is used, then the tire can be tested on a rotating road wheel, but the shoulder wear on the tire tread becomes notably higher than when tested on a flat surface

Engineering Contradiction:
Improvetire testing capabilityVSAvoidshoulder wear on tire tread
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies curvature to the lateral profile of the tire operating surface, transitioning from a flat cylindrical surface to a contoured surface with a radius of curvature. This curvature modification changes the contact mechanics between the tire and wheel, distributing the contact pressure more evenly across the tire tread width and reducing concentrated stress at the shoulders, thereby reducing shoulder wear while maintaining the rotating road wheel testing capability

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If a cylindrical outer tire operating surface is used, then the tire testing can be performed, but the footprint of the tire becomes different from that achieved on a generally flat surface

Engineering Contradiction:
Improvetire testing efficiencyVSAvoidfootprint accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent modifies the geometric parameters of the tire operating surface by introducing a contoured lateral profile with specific radius of curvature values. This parameter change alters the contact patch geometry and pressure distribution, enabling the generation of a footprint that more accurately represents real-world flat surface conditions while maintaining efficient tire testing capability

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The laterally-contoured tire operating surface reduces shoulder wear and generates a more representative tread wear distribution and footprint, closely resembling those from real-world flat surface conditions, enhancing the accuracy of tire testing.

Implementation Method 1

When a tire contacts a tire operating surface, whether it is a wheel surface or a ground surface, a portion of the tire tread contacts the operating surface. The portion of the tread contacting the operating surface forms an area of contact, which is referred to as a contact patch or footprint of the tire.

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

it has been observed that tires tested on these cylindrical surfaces commonly exhibit notably higher wear on the shoulders of the tire treads than those tires tested on a generally flat surface

Methodology Applied
Scientific EffectWear: Wear

Data Source

PatentEP2798123B1Method and apparatus for reducing shoulder wear on testing wheel
Publication Date: 2019.08.28 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP2798123B1 patent drawingFigure 1
  • EP2798123B1 patent drawingFigure 2~3
  • EP2798123B1 patent drawingFigure 4

AI summary

The present invention includes methods and apparatus for testing tire performance using a laterally-contoured road wheel. Accordingly, particular embodiments of the machine include a wheel configured to rotate, the wheel having a tire operating surface configured to engage a tire during operation, the outer tire operating surface arranged along an annular side of the wheel and having a width extending laterally relative a circumferential direction of the wheel along a contoured path. The machine may further include a drive source configured to rotate the wheel and a tire mount configured to rotatably maintain a tire. The present invention also includes methods of forming a laterally-contoured tire operating surface for a road wheel.