Non-Pneumatic Tire Spoke Ring Structure for Top-Load Support
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Solution Overview
Problem
Conventional pneumatic tires require air inflation, making them vulnerable to loss of pressure and necessitating pressure maintenance and monitoring, while non-pneumatic tires lack the performance and tread life of pneumatic tires.
Innovation Solution
A non-pneumatic tire and wheel assembly featuring a spoke ring structure with a plurality of spoke members and an outer tread ring, where at least one spoke member has a radiused axially outer edge, and a shear band that transfers load from the tread to the spokes and hub, creating a top-loading structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-pneumatic tire uses a rigid structurally supported design, then it eliminates the need for air inflation and pressure monitoring, but it fails to provide adequate load carrying efficiency and performance comparable to pneumatic tires
Solution Approach 1:
The tire is divided into multiple functional segments: an outer tread ring for load distribution, a spoke ring structure with multiple spoke members for structural support, and a hub assembly. This segmentation allows each component to specialize in specific functions, enabling the non-pneumatic tire to achieve pneumatic-like performance without requiring inflation pressure.
Solution Approach 2:
The tire employs composite material construction with the outer tread ring made from elastomeric materials and the spoke ring structure using rigid materials. This combination of materials with different properties enables the structure to simultaneously provide flexibility for comfort and rigidity for load carrying, resolving the contradiction between reliability without pressure and strength for load support.
2Device complexity
If a non-pneumatic tire uses a bottom loader rigid structure, then it simplifies the design, but it concentrates load in the portion below the hub resulting in reduced load carrying efficiency
Solution Approach 1:
Instead of concentrating load at the bottom (bottom loader design), the invention inverts the load path by designing the outer tread ring to engage the full circumference and distribute load across all spoke members uniformly. This top-loader approach ensures all structural elements participate in load carrying, maximizing load carrying efficiency while maintaining design simplicity.
3Reliability
If a non-pneumatic tire uses conventional elastomeric structures, then it eliminates the need for inflation, but it produces excessive noise and lacks the tread life of pneumatic tires
Solution Approach 1:
The separation of the outer tread ring from the spoke ring structure allows the tread to roll smoothly while the rigid spokes remain stationary relative to the hub. This segmentation prevents the noise generated by flexible elastomeric structures deforming under load, while still maintaining the no-inflation advantage. The tread ring can be replaced independently to extend service life.
4Strength
If a non-pneumatic tire uses a top loader design with all structure involved in load carrying, then it achieves higher load carrying efficiency, but it increases the mass of the tire
Solution Approach 1:
The spoke members are designed with varying cross-sectional areas and wall thicknesses optimized for their specific positions and load conditions. Spokes experiencing higher loads have greater structural capacity, while those in lower stress regions use less material. This local optimization achieves high load carrying efficiency without uniformly increasing the mass of the entire tire structure.
Data Source
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AI summary
A non-pneumatic tire and wheel assembly (10) is disclosed comprising a wheel structure (50) and a spoke ring structure (20) formed of one or more segments (22a, 24a, 26a) arranged to form an annular spoke ring. The spoke ring structure (20) has a plurality of spoke members (60, 62). Further, a radially outer tread ring (30) mounted on the outer circumference of the spoke ring structure (20) is provided. The non-pneumatic tire and wheel assembly (10) can be manufactured by three-dimensional printing.