Tire Rib Shift Methodology for Second Order Harmonic Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tire designs experience vibrations and non-uniformity at high speeds due to tire/road contact forces, which are amplified by tire construction non-uniformities and resonances, leading to rhythmic beating and increased vibration amplitude with vehicle speed.
Innovation Solution
The method involves analyzing and minimizing second and nth order harmonics of force variations by circumferentially shifting the ribs of the tire tread design, using computer simulations or high-speed uniformity machines to optimize the tread pattern, specifically shifting the pitch sequence of block elements in the ribs to reduce harmonic amplitudes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional tire tread designs are used, then manufacturing simplicity is maintained, but high-speed uniformity deteriorates due to amplified vibrations and force variations
Solution Approach 1:
The patent applies asymmetry by implementing non-uniform rib designs where ribs are shifted circumferentially by different amounts relative to each other. Specifically, first and second ribs are shifted by different circumferential distances, creating an asymmetric tread pattern that disrupts the periodicity of force variations and minimizes second order harmonics, thereby improving high-speed uniformity without requiring complete redesign of the entire tire structure
Solution Approach 2:
The patent applies local quality by varying the rib shift amounts locally rather than uniformly across all ribs. Each rib can be shifted by a different circumferential distance, allowing targeted optimization of specific regions of the tread to minimize harmonics at critical locations while maintaining overall tread functionality and manufacturing feasibility
2Reliability
If rib shifting is applied to minimize second order harmonics, then high-speed uniformity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by optimizing the specific circumferential shift distances of ribs to minimize second order harmonics. By carefully selecting and adjusting the shift parameters (circumferential distances) for each rib, the design achieves harmonic minimization while establishing clear manufacturing specifications that guide precision requirements, balancing performance improvement with manufacturability
3Ease of manufacture
If conventional symmetric tread patterns are used, then ease of manufacture is maintained, but vibration amplitude increases at high speeds
Solution Approach 1:
The patent replaces symmetric tread patterns with asymmetric rib configurations where ribs are shifted by different circumferential amounts. This asymmetry breaks the periodic symmetry that amplifies vibrations at high speeds, reducing the amplitude of force variations and harmful vibrations while maintaining a manufacturing process that builds upon conventional tread production methods
Solution Approach 2:
The patent converts the potentially harmful effect of rib positioning into a beneficial anti-vibration mechanism. By deliberately introducing controlled asymmetric shifts in rib positions, the design transforms what would normally be sources of periodic vibration into a system that disrupts harmonic resonance, turning the structural elements into vibration-dampening features that improve high-speed uniformity
Data Source
AI summary
A method of improving the high-speed uniformity of tire performance that reduces low and/or high harmonics. The method includes determining a force variation that is created by rotation of a first tire, having a first tread design, at high speed. A second order harmonic of the force variation is analyzed. A second tire design is generated that circumferentially shifts one or more ribs of the first tread design to minimize the second order harmonic alone or in combination with other order harmonics.