Compact Pneumatic Tire Groove Layout for Uniform Contact Pressure
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Solution Overview
Problem
Small-diameter pneumatic tires face issues with uneven ground contact pressure due to short ground contact length and small contact area, leading to uneven wear, while also needing to support high loads and save space on vehicles like small shuttle buses.
Innovation Solution
A pneumatic tire design with a specific size and configuration, including a wide tire width, moderate aspect ratio, and strategically placed circumferential main grooves, to distribute load evenly and reduce wear, while maintaining a small diameter for space efficiency and supporting high loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the tire diameter is reduced to save space, then the ground contact length becomes short and ground contact area becomes small, but the load to be supported remains high, causing uneven ground contact pressure and uneven wear
Solution Approach 1:
The invention applies local quality by creating circumferential main grooves at specific positions on the tread surface. These grooves are strategically placed to control ground contact pressure distribution in high-pressure regions, allowing different parts of the tire to have different functional characteristics. The grooves modify the local structure to achieve uniform pressure distribution while maintaining small overall tire dimensions.
Solution Approach 2:
The invention changes physical parameters by defining specific relationships between tire dimensions (width SW, outer diameter OD, rim diameter RD) and groove positioning (distance a1, a2 from equatorial line). By optimizing these parameters, the tire achieves uniform ground contact pressure despite reduced diameter, resolving the contradiction between compact size and pressure uniformity.
2Volume of moving object
If the tire diameter is reduced to save space, then the ground contact length becomes short, but the load-carrying capacity must be maintained at high levels
Solution Approach 1:
The invention optimizes dimensional parameters by establishing specific relationships: rim diameter RD between 12-17.5 inches, tire width SW of 125-255 mm, aspect ratio of 35-75%, and outer diameter OD of 350-600 mm. These parameter changes enable the tire to maintain high load-carrying capacity while achieving reduced overall diameter for space savings.
Solution Approach 2:
The circumferential main grooves are positioned at specific distances (a1, a2) from the equatorial line to create optimal load distribution patterns. This local structural modification allows the tire to support high loads despite the reduced contact length associated with smaller diameter.
3Area of stationary object
If the tire width is increased to improve load distribution, then the ground contact area increases, but the overall tire size increases reducing space saving
Solution Approach 1:
The invention defines optimized parameter ranges including tire width SW of 125-255 mm and outer diameter OD of 350-600 mm, with aspect ratio between 35-75%. These parameter changes achieve sufficient ground contact area for load distribution while controlling overall tire size to maintain space-saving characteristics.
Solution Approach 2:
Instead of simply increasing width, the invention uses circumferential grooves to modify the third dimension (tread depth profile) to optimize contact characteristics. This dimensional approach allows improved load distribution without proportionally increasing overall tire volume.
Data Source
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AI summary
The outer diameter of the pneumatic tire (10) is 350 mm or more and 600 mm or less, and as RW is defined by a rim width of a rim wheel assembled to the pneumatic tire and SW is defined by a tire width of the pneumatic tire, the relation of 0.78 ≤ RW/SW ≤ 0.99 is satisfied, and at least two circumferential main grooves extending to the tire circumferential direction are formed in the tread. The circumferential main groove is formed closer to a tire equatorial line (CL) than an outer end in the tire width direction of the belt layer.