Multi-Layer Tire Tread with Variable Thickness for Wet Traction

Solution Overview

Problem

Conventional tire treads face a trade-off between traction, rolling resistance, and treadwear, where improving one characteristic often compromises the others, leading to undesirable variations in performance as the tire wears, particularly in inclement weather conditions.

Innovation Solution

A pneumatic tire design featuring an outer and inner tread layer with different elastomeric compounds, where the inner layer provides greater traction and the outer layer offers lower rolling resistance and improved wear resistance, with a thickness variation that maintains optimal performance throughout the tire's life by gradually exposing more of the inner layer as the outer layer wears.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a compound with good traction properties is selected for the tread, then wet traction is improved, but rolling resistance increases

Engineering Contradiction:

Improvewet tractionVSAvoidrolling resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The tread is divided into multiple layers (outer tread layer, intermediate tread layer, and inner tread layer) with different compound formulations. The outer layer provides traction, the intermediate layer provides wear resistance, and the inner layer provides low rolling resistance, allowing each layer to optimize its specific function without compromising the others.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the tread are assigned different compound properties tailored to their specific functional requirements. The outer tread layer has higher silica content for traction, the intermediate layer has higher polymer content for wear resistance, and the inner layer has lower silica content for reduced rolling resistance, creating local optimization throughout the tread structure.

Inventive Principle:

Principle #3Local quality

2Duration of action of stationary object

If a compound ideal for reducing treadwear is selected, then wear resistance is improved, but traction deteriorates

Engineering Contradiction:

Improvetreadwear resistanceVSAvoidtraction

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The tread is divided into multiple layers (outer tread layer, intermediate tread layer, and inner tread layer) with different compound formulations. The outer layer provides traction, the intermediate layer provides wear resistance, and the inner layer provides low rolling resistance, allowing each layer to optimize its specific function without compromising the others.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the tread are assigned different compound properties tailored to their specific functional requirements. The outer tread layer has higher silica content for traction, the intermediate layer has higher polymer content for wear resistance, and the inner layer has lower silica content for reduced rolling resistance, creating local optimization throughout the tread structure.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If the tread pattern volume is reduced as the tread wears, then rolling resistance decreases, but wet traction deteriorates

Engineering Contradiction:

Improverolling resistanceVSAvoidwet traction

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The tread is designed with an intermediate wear-resistant layer positioned between the outer and inner layers. This layer is formulated to wear at a controlled rate, preliminarily protecting the inner low rolling-resistance layer while maintaining adequate tread pattern volume for wet traction during the tire's service life.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The tread structure is designed to dynamically adapt its composition as it wears. The intermediate layer is engineered to erode preferentially, gradually exposing the inner layer with different properties, allowing the tire's performance characteristics to evolve favorably over time while maintaining the tread pattern volume necessary for wet traction.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9022084B2Passenger tire having low rolling resistance with improved wet traction and treadwear

Publication Date: 2015.05.05 THE GOODYEAR TIRE & RUBBER CO

AI summary

A tire having a tread includes an outer tread layer and an inner tread layer. The inner tread layer includes one of a first elastomeric compound and a second elastomeric compound. The outer tread layer includes the other of the first and second elastomeric compounds. The second elastomeric compound has a lower rolling resistance and greater resistance to treadwear than the first elastomeric compound. The inner tread layer increases in thickness across at least a widthwise portion of the outer tread layer with a maximum thickness of one of the inner tread layer and the outer tread layer occurring near at least one of a first shoulder and a second shoulder of the tread. As the tread wears, the inner tread layer defines a greater proportion of a running surface of the tread.