Zigzag Belt Structure for Heavy-Load Tire Weight Reduction
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Solution Overview
Problem
Zigzag belt layers in heavy-load tires, such as truck and aircraft tires, while improving durability by eliminating cut belt edges, result in excessive overlapping layers at the shoulder, leading to increased weight and reduced efficiency.
Innovation Solution
A modified zigzag belt structure with specific winding patterns and combinations of cord layers, including low-angle belts and crossed belts, optimized to reduce overlapping while maintaining durability, featuring sequences like W2W1 and W1W2 repeated multiple times per drum revolution, and incorporating different amplitudes to distribute load effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zigzag belt layers are used in heavy-load tires, then belt edge durability is improved by eliminating cut belt edges, but the number of overlapping layers at the shoulder increases excessively (4 or more layers, even 6 or more in some locations), leading to increased weight
Solution Approach 1:
The belt package is segmented into distinct functional layers: zigzag belt layers (for durability at belt edges) and working belt layers (for load carrying). The zigzag belts are positioned primarily in the shoulder regions with reduced overlap, while working belts provide structured reinforcement in the central tread area. This segmentation allows each layer to perform its specific function without excessive overlapping throughout the entire tire.
Solution Approach 2:
Different belt structures are applied to different regions of the tire. Zigzag belts with specific winding patterns (W1W2, W2W1 sequences) are used in shoulder areas where cut edge prevention is critical, while working belts with standardized angles (15-30 degrees) are used in the central tread area for optimal load distribution. This local differentiation optimizes both durability and weight distribution.
2Reliability
If multiple zigzag belt layers are used to ensure coverage and durability, then belt edge protection is improved, but the complexity of the belt structure increases and material usage increases
Solution Approach 1:
The belt package is divided into functional segments: zigzag belts for shoulder protection and working belts for central tread reinforcement. This segmentation reduces overall structural complexity by assigning specific functions to specific layers, avoiding the need for multiple full-width zigzag layers throughout the entire tire.
Solution Approach 2:
Zigzag belts are applied partially in the shoulder regions rather than across the entire tire width. The winding patterns (W1W2, W2W1) create adequate coverage in critical areas without excessive overlap in non-critical zones, reducing material usage while maintaining protective function.
3Ease of manufacture
If zigzag belt layers are used with traditional winding patterns, then manufacturing is simplified, but overlapping strips in the shoulder area cannot be reduced, limiting durability improvement
Solution Approach 1:
The zigzag belts employ dynamic winding patterns (W1W2, W2W1 sequences) that vary the amplitude and direction of zigzag waves across different layers. This dynamic approach allows optimization of overlap distribution in shoulder areas while maintaining manufacturing feasibility through standardized winding procedures.
Solution Approach 2:
The winding patterns use asymmetric amplitude sequences (W1 different from W2) to strategically position belt edges and reduce overlapping in shoulder regions. This asymmetric design maintains manufacturing simplicity while achieving reduced overlap counts compared to traditional symmetric zigzag patterns.
Data Source
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AI summary
A pneumatic tire comprising a tread (25), a carcass (31) and a belt structure (40) interposed between the carcass (31) and the tread (25) is disclosed. The belt structure (40) includes a zigzag belt structure (39) formed of at least two layers of cords interwoven together from a strip of rubber reinforced with one or more cords, wherein the strip forming the zigzag belt structure (39) is laid up in a winding pattern in accordance with the following formula: for i =1 through L, the ith winding cycle is: [WL-(i-1)Wi] x N for each revolution, wherein L is the number of different amplitudes W1, .... WL used to define the zigzag belt structure (39) and L ≥ 2, and N is the number of zigzag cycles per revolution.