Pneumatic Tire Barrier Layer Bead Reinforcement
Solution Overview
Problem
Aircraft tires face premature bead failure due to severe operating conditions, high loads, and increased hysteresis losses from multiple carcass plies, leading to shorter operational life and higher operating temperatures.
Innovation Solution
Incorporating a barrier layer of low denier, high end count fabric between the carcass structure and the innerliner, with fabric pieces on each side of the tire's centerline, anchored around the bead cores to prevent innerliner compound migration and enhance tire strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If multiple carcass plies are used to reinforce the tire, then the load carrying capacity and structural strength are improved, but the hysteresis losses and operating temperatures increase leading to shorter operational life
Solution Approach 1:
The patent changes the material parameters by introducing a barrier layer with specific properties (low denier, high end count fabric) that has different hysteresis characteristics than traditional carcass plies. This layer is positioned between the carcass and innerliner to specifically address energy loss while maintaining structural integrity. The barrier layer's unique fabric composition and arrangement reduce overall tire hysteresis without compromising load capacity.
2Strength
If multiple carcass plies are used to reinforce the tire, then the structural strength is improved, but the operating temperatures increase contributing to fatigue failure
Solution Approach 1:
The barrier layer acts as an intermediary element between the carcass structure and the innerliner. This intermediate layer has thermal properties that help manage heat generation and distribution. By positioning this specific fabric layer at the interface, it mediates the thermal environment, reducing temperature buildup that would otherwise contribute to fatigue failure in the high-stress carcass regions.
3Ease of manufacture
If the innerliner is placed directly against the carcass structure, then the manufacturing process is simplified, but the innerliner compound migrates into the carcass plies reducing tire performance
Solution Approach 1:
The barrier layer serves as a mediator between the innerliner and carcass structure, preventing direct contact between the innerliner compound and the carcass plies. This intermediate fabric layer is permeable enough to allow manufacturing processes but sufficiently barrier-like to prevent compound migration. The low denier, high end count construction allows it to function as an effective barrier while maintaining compatibility with the surrounding structures.
4Reliability
If a barrier layer is added between the carcass and innerliner, then the tire strength and durability are improved, but the device complexity and manufacturing steps increase
Solution Approach 1:
The barrier layer is constructed as a thin, flexible fabric membrane with low denier and high end count characteristics. This thin-film approach provides the necessary barrier and reinforcement functions without adding significant bulk or complexity to the tire structure. The flexible nature of the fabric allows it to integrate smoothly with the existing tire construction processes and components.
Data Source
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AI summary
A pneumatic tire (100) comprises a tread (12), a crown reinforcement (10) radially inward of the tread, a pair of bead cores (33), a carcass structure (20) radially inward of the crown reinforcement (10), an innerliner (22) radially inward of the carcass structure (20), and a barrier layer (101) interposed between the carcass structure (20) and the innerliner (22). The barrier layer (101) comprises at least two fabric pieces or fabric plies, one on each side of a center line (CL) of the pneumatic tire (100). One end of each fabric piece or ply is wrapped around a respective bead core (33) and terminates at least at the radial outermost part of the bead cores or radially outwardly of the outermost part of the respective bead core (33).