Tire-Wheel Assembly With Low-Loss Tread for Wireless Power Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tire-wheel assemblies face inefficiencies in wireless power supply from outside the tread portion in a radial direction, particularly when using high-frequency power transmission.
Innovation Solution
The tire-wheel assembly incorporates low-loss tread rubber with a loss tangent of 0.25 or less, a specific gauge ratio of sidewall to bead width, and optimized power receiving coil positioning to enhance power receiving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless power supply is implemented from outside the tread portion in radial direction, then convenience of power supply for electric vehicle is enhanced, but power receiving efficiency is reduced
Solution Approach 1:
The patent changes the material parameter of the tread rubber by selecting a rubber composition with specific loss tangent characteristics (tanδ ≤ 0.25 at 60°C). This parameter change reduces energy loss during wireless power transmission through the tread, thereby improving power receiving efficiency while maintaining the convenience of wireless power supply from outside the tire
Solution Approach 2:
The patent uses composite rubber composition comprising specific rubber components (natural rubber, styrene-butadiene copolymer rubber, polybutadiene rubber) in optimized proportions. This composite material structure achieves both low loss tangent for improved power receiving efficiency and appropriate mechanical properties for tire performance
2Power
If high-frequency power transmission is used, then power transmission capability is improved, but heat generation increases and power receiving efficiency decreases
Solution Approach 1:
The patent optimizes the loss tangent parameter of the tread rubber specifically for high-frequency operation. By selecting rubber composition with tanδ ≤ 0.25 at 60°C (which corresponds to high-frequency vibration conditions), the patent reduces heat generation during high-frequency power transmission while maintaining adequate power transmission capability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration improves power receiving efficiency, especially at high frequencies, while reducing heat generation and maintaining tire performance characteristics such as handling stability and ride comfort.
Implementation Method 1
a power receiving coil (secondary coil) 51 configured to receive a wireless supply of electric power from a power transmission coil (primary coil) 71
Implementation Method 2
The tread rubber has a loss tangent tanδ of 0.25 or less at 60°C
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A tire-wheel assembly and a tire used in the tire-wheel assembly, the tire-wheel assembly includes the tire having a tread portion, a sidewall portion, and a bead portion, and a wheel on which the tire is mounted, the tire-wheel assembly configured such that electric power is wirelessly supplied from outside the tread portion in a tire radial direction to a power receiving device disposed inside the tread portion of the tire in the tire radial direction. The tread portion contains low-loss tread rubber having a loss tangent tanδ of 0.25 or less at 60°C, and a ratio Ts/Tb between a gauge Ts of the sidewall portion at a tire maximum width portion and a bead width Tb of a bead core at a center position in the tire radial direction is 15% or more and 60% or less.