Multi-Layer Tire Tread for Wear and Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heavy-duty tires face issues with endurance and rolling resistance due to shear stresses and temperature increases in the crown reinforcement, leading to premature wear and reduced distance before retreading is necessary.
Innovation Solution
A tire design featuring a tread composed of multiple radially superposed elastomeric compounds, with a first layer for wear resistance and subsequent layers optimized for hysteresis and rolling resistance, including a third layer with specific filler compositions and properties to enhance durability and reduce temperature rises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single elastomeric compound is used for the tread, then the structure is simple and manufacturing is easier, but wear resistance and rolling resistance cannot be simultaneously optimized
Solution Approach 1:
The tread is segmented into multiple layers, each with distinct elastomeric compounds optimized for specific functions. The first layer (outermost) uses a compound with high wear resistance properties, while the second layer (inner) uses a compound with optimized hysteresis characteristics for rolling resistance reduction. This segmentation allows each layer to perform its specialized function independently.
Solution Approach 2:
Different regions of the tread are assigned different material properties according to their functional requirements. The outer layer is designed with harder, more wear-resistant material to withstand ground contact and mechanical abrasion, while the inner layer uses softer, more elastic material to optimize energy dissipation and reduce rolling resistance. Each layer's composition is locally optimized for its specific role.
2Loss of energy
If high hysteresis material is used to reduce rolling resistance, then energy loss is reduced, but wear resistance deteriorates
Solution Approach 1:
The tread is divided into functional layers: the outer layer uses material optimized for wear resistance with appropriate hysteresis characteristics, while the inner layer uses material specifically optimized for low rolling resistance with different hysteresis properties. This segmentation allows the wear-resistant outer layer to protect the tire while the inner layer minimizes energy loss during deformation cycles.
Solution Approach 2:
The tread employs a composite structure with two different elastomeric compounds bonded together. The first compound (outer layer) is formulated with specific polymer blends and fillers for wear resistance, while the second compound (inner layer) is formulated with different composition ratios to optimize hysteresis and reduce rolling resistance. The composite structure combines the advantages of both material systems.
3Reliability
If the tread wears through to the crown reinforcement, then the tire structure is compromised, but retreading becomes necessary reducing overall tire life
Solution Approach 1:
The tread is designed with sufficient thickness and optimized wear characteristics to delay the onset of retreading operations. The outer layer's wear-resistant properties slow down material loss, extending the service life before the tread wears through to the crown reinforcement layer, thereby maximizing the distance the tire can operate before requiring retreading.
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 tire achieves improved wear resistance, reduced rolling resistance, and extended distance before retreading, maintaining performance while allowing for efficient retreading without visible layer exposure.
Implementation Method 1
a second layer of elastomeric compounds radially on the inside of and in contact with the said first layer of elastomeric compound consisting of at least three parts, the axially outer parts of the said second layer consisting of a second elastomeric compound having a maximum value of tan (δ), denoted tan(δ)max, strictly less than 0.060
Data Source
AI summary
A tire with a radial carcass reinforcement, having a crown reinforcement, itself capped radially by a tread connected to two beads by two sidewalls, having at least two radially superposed layers of elastomeric compounds; a first layer, forming the radially outer part of the tread, has a first elastomeric compound having a modulus G* greater than 1.8 MPa, a second layer of elastomeric compounds radially on the inside of and in contact with the said first layer of elastomeric compound has at least three parts, the axially outer parts having a second elastomeric compound having a maximum value of tan (δ), denoted tan (δ) max, strictly less than 0.060, and at least a part of the second layer, axially in contact with at least an axially outer part having a third compound with modulus G* greater than 1.2 MPa and at least 5% less than the first elastomeric compound and a maximum value of tan (δ), tan (δ)max, between 0.060 and 0.120.