Heavy Load Tyre Belt Structure Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Heavy load vehicle tires face reduced service life due to thermal-mechanical stresses causing micro-lacerations and fatigue, leading to irregular wear and vibrations, which are exacerbated by increased load indices and travel speeds, necessitating a stronger belt structure to withstand more stress cycles and allow for tread band reconstructions.

Innovation Solution

A tire design featuring three radially innermost belt layers: a first belt layer with reinforcing elements oriented in various directions, a central belt layer with elements oriented circumferentially, and lateral reinforcing layers, along with a sheet of elastomeric material between the first and second belt layers, to distribute deformations and reduce strain on the elastomeric material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If the belt structure is strengthened to withstand more stress cycles, then service life is improved, but device complexity increases due to multiple belt layers

Engineering Contradiction:
Improveservice lifeVSAvoidbelt structure complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The belt structure is divided into multiple functional layers: a first belt layer with circumferential reinforcing elements, a second belt layer with inclined reinforcing elements, and a third belt layer with circumferential reinforcing elements. Each layer serves a specific function in distributing different types of stresses, allowing the structure to withstand more stress cycles and extend service life while maintaining manageable complexity through functional segmentation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material construction by combining different types of reinforcing elements (circumferential and inclined) in multiple layers within the belt structure. This composite approach allows the belt to resist various stress components simultaneously, improving durability and service life under heavy load conditions without requiring excessive material in a single configuration.

Inventive Principle:
Principle #40Composite materials

2Strength

If the belt structure uses multiple layers to distribute deformations, then stress resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvestress resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The belt structure is segmented into three distinct layers, each with specific reinforcing element orientations. The first and third layers provide circumferential strength to resist radial forces, while the second layer with inclined elements distributes shear stresses. This segmentation improves stress resistance while allowing each layer to be manufactured and positioned with clear functional requirements, simplifying the overall manufacturing process compared to a monolithic complex structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each belt layer is designed with local quality characteristics: the first and third layers have circumferential reinforcing elements optimized for radial force resistance, while the second layer has inclined elements specifically positioned to handle shear stresses. This localized optimization of material properties and orientations in different regions of the belt structure enhances overall stress resistance while maintaining manufacturing feasibility through standardized layer construction.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If the reinforcing elements are oriented in various directions, then deformation distribution is improved, but structural complexity increases

Engineering Contradiction:
Improvedeformation distributionVSAvoidstructural complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The belt structure segments reinforcing elements into different orientation groups across three layers: circumferential orientation in the first and third layers for radial force resistance, and inclined orientation in the second layer for shear stress distribution. This segmentation achieves comprehensive deformation distribution while maintaining structural clarity and manageability through distinct functional zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs asymmetric orientation of reinforcing elements: the first and third layers use circumferential orientation while the second layer uses inclined orientation at specific angles. This asymmetric arrangement optimizes deformation distribution by matching element orientation to the dominant stress direction in each layer, improving structural efficiency without requiring symmetric complexity throughout the entire belt structure.

Inventive Principle:
Principle #4Asymmetry

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

This configuration significantly reduces fatigue cycles and strain on the tire's reinforcing elements, enhancing service life by distributing deformations and reducing heat generation, thereby improving stress resistance and reconstructability of the tire.

Implementation Method 1

a sheet of elastomeric material between the first and second belt layers, to distribute deformations and reduce strain on the elastomeric material

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

thermal-mechanical stresses exerted on the belt structure of the tyre, can trigger micro-lacerations which, upon propagation, reduce the service life thereof

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3463932B1Tyre for heavy load vehicle wheels
Publication Date: 2020.08.05 PIRELLI TYRE SPA
  • EP3463932B1 patent drawingFigure 1
  • EP3463932B1 patent drawingFigure 2~3
  • EP3463932B1 patent drawingFigure 4

AI summary

A tyre (100) for heavy duty vehicle wheels comprising: - a carcass structure (101); and - a belt structure (105); and - a tread band (106), wherein the belt structure (105) comprises: - a first belt layer (105a) incorporating reinforcing elements, oriented in one or more directions, and selected from cords made of non- metallic material; - a second belt layer (105b) applied on the first belt layer (105a) and comprising: i) a pair of lateral reinforcing layers (113) positioned at axially outer ends of said second belt layer (105b), said lateral reinforcing layers (113) incorporating reinforcing elements oriented along a substantially circumferential direction, and ii) a central belt layer (114) axially interposed between said pair of lateral reinforcing layers (113) and incorporating reinforcments oriented in one or more directions; - optionally, a sheet of elastomeric material (105g) arranged between said at least a first belt layer (105a) and said second belt layer (105b) - a third belt layer (105c), radially outerside of the second belt layer (105b) and incorporating inclined reinforcing elements; and - a fourth belt layer (105d), radially outerside of the third belt layer (105c) and incorporating inclined reinforcing elements at an opposite direction with respect to that of the third belt layer (105c).