Tyre Rim Guard Angle Gap Aerodynamics
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Solution Overview
Problem
Existing pneumatic tire and rim assemblies do not effectively reduce air resistance, which limits fuel efficiency.
Innovation Solution
A tire and rim assembly with a rim guard that protrudes outward from the sidewall to cover the rim flange, featuring a specific angle and maximum gap between the rim guard and flange to minimize air resistance, and a concave circular arc surface to suppress air flow, enhancing fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the rim guard protrudes outward to cover the flange, then air resistance is reduced, but the structural complexity increases
Solution Approach 1:
The rim guard is designed as a separate component that can be integrated with the bead portion, allowing it to function as both a protective element and an aerodynamic fairing. This segmentation enables the rim guard to cover the flange and reduce air resistance without requiring complete redesign of the entire wheel assembly
Solution Approach 2:
The rim guard extends in the axial direction from the bead portion to cover the flange, utilizing the third dimension (axial direction) to achieve aerodynamic benefits. By positioning the rim guard to protrude axially, the design creates a streamlined profile that guides air flow over the wheel assembly, reducing turbulence and drag
2Object-affected harmful factors
If the rim guard angle θ is reduced to equal to or less than 40 degrees, then air resistance is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The invention specifies a quantitative parameter (angle θ ≤ 40 degrees) for the rim guard's inclination relative to the radial direction. This parameter control optimizes the balance between aerodynamic performance and manufacturability, ensuring that the rim guard achieves sufficient air resistance reduction while remaining feasible to manufacture with standard precision capabilities
3Object-affected harmful factors
If the maximum gap between the flange and rim guard is reduced to equal to or less than 2.0 mm, then air resistance is reduced, but the ease of manufacture decreases
Solution Approach 1:
The invention establishes a specific gap parameter (maximum gap ≤ 2.0 mm) between the flange and rim guard to optimize aerodynamic performance. This parameter represents a practical threshold that achieves effective air resistance reduction while remaining compatible with standard manufacturing tolerances and assembly processes
Data Source
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AI summary
A tyre and rim assembly includes a rim (R) having a pair of flanges, and a pneumatic tyre (1) being mounted onto the rim, the pneumatic tyre including a pair of bead portions and a rim guard (10) being provided on at least one of the pair of bead portions; in a cross-sectional view of the assembly under a standard state, the rim guard (10) protrudes outwardly in a tyre axial direction from a sidewall reference outer surface (J) of the tyre so as to cover over one of the pair of flanges; an angle θ of an imaginary rim guard straight line (11) with respect to a tyre radial direction is equal to or less than 40 degrees, and a maximum gap (A) in the tyre radial direction between the one of the pair of flanges (Rb) and the rim guard (10) is equal to or less than 2.0 mm