Tire Toroidal Element Variable Thickness

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Solution Overview

Problem

Existing tire technologies face challenges in maintaining structural integrity and durability without internal air pressure, particularly in non-pneumatic and run-flat tire designs, which require innovative solutions for load-carrying capacity and flexibility.

Innovation Solution

A toroidal element is integrated into the tire, comprising a central rubber component sandwiched between body plies, providing high interlaminar shear strength and flexural modulus, allowing the tire to flex under load without internal air pressure, and constructed using various materials and fabrication techniques to enhance durability and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a thin annular high strength band element is used in run flat tires, then structural integrity is maintained when pressurized, but the tire cannot operate without internal air pressure

Engineering Contradiction:
Improvestructural integrityVSAvoidoperability without internal air pressure
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent uses a toroidal element with variable thickness that acts as a flexible structural component. The element has a maximum thickness in the crown region and tapers toward the sidewalls, creating a self-supporting structure that maintains integrity without requiring internal air pressure. This flexible shell structure enables the tire to function in both pneumatic and non-pneumatic modes.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The toroidal element's thickness parameter varies continuously around the tire circumference. By changing the thickness parameter from the crown region toward the sidewalls, the structure achieves optimal strength where needed while maintaining flexibility and weight efficiency in other regions, enabling operation without constant internal pressure.

Inventive Principle:
Principle #35Parameter changes

2Force

If internal air pressure is used in pneumatic tires, then load-carrying capacity is improved, but structural integrity is lost when unpressurized

Engineering Contradiction:
Improveload-carrying capacityVSAvoidstructural integrity
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The toroidal element is pre-formed with an optimized variable thickness profile before tire assembly. This preliminary structuring provides inherent load-carrying capability and structural stability independent of internal air pressure, allowing the tire to maintain its shape and support loads in both inflated and deflated states.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The tire construction combines the toroidal element with body plies and rubber materials to create a composite structure. The toroidal element provides the primary structural framework, while the body plies and rubber materials supplement the load-carrying capacity and flexibility, achieving stable structural integrity without relying solely on internal air pressure.

Inventive Principle:
Principle #40Composite materials

3Strength

If a toroidal element with variable thickness is used, then interlaminar shear strength is enhanced, but manufacturing complexity increases

Engineering Contradiction:
Improveinterlaminar shear strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The toroidal element implements local quality by having different thicknesses at different locations around the tire. The maximum thickness is positioned in the crown region where interlaminar shear stresses are highest, providing enhanced strength precisely where needed. The thickness gradually reduces toward the sidewalls, optimizing the strength-to-weight ratio while managing manufacturing complexity through a systematic gradient rather than abrupt variations.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3049257B1Tire with toroidal element
Publication Date: 2019.02.20 BRIDGESTONE AMERICAS TIRE OPERATIONS LLC
  • EP3049257B1 patent drawingFigure 1
  • EP3049257B1 patent drawingFigure 2
  • EP3049257B1 patent drawingFigure 3~5

AI summary

A tire includes a tread formed in a crown region of the tire and sidewall regions extending from the crown region to bead areas. The tire further includes a toroidal element extending across a crown region of the tire, and further extending along at least a portion of each sidewall region of the tire. The toroidal element has a central region located between inner and outer regions. The central region is more elastic than the inner and outer regions.