Wheel Rim Power Reception Layout for Obstacle-Resistant Wireless Charging

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Solution Overview

Problem

Existing power reception devices on vehicle wheels are susceptible to efficiency reduction due to obstacles interfering with wireless power transmission from road-based power transmission devices.

Innovation Solution

A tire/wheel assembly with a power reception device on the outer peripheral surface of the rim, a non-magnetic tread portion, and a relay device on the inner peripheral surface, optimized to enhance power reception efficiency through electromagnetic induction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a power reception device is installed on the underside of the vehicle to receive wireless power from a road-based power transmission device, then wireless power supply is enabled, but obstacles such as metal or small animals may enter the space between the power reception device and the power transmission device, reducing power reception efficiency

Engineering Contradiction:
Improvewireless power reception efficiencyVSAvoidobstacle interference
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent moves the power reception device from the traditional underside location to the wheel rim, changing the spatial dimension of power reception. This dimensional shift allows the reception coil to be positioned on the outer peripheral surface of the rim, where it can receive power from a road-based transmission device without being blocked by obstacles in the traditional gap space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The tire acts as an intermediary medium between the power transmission device and the power reception device on the wheel rim. The tire's non-magnetic material properties allow magnetic field penetration while physically separating the reception coil from potential obstacles, mediating the power transfer process effectively.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the tire sidewall gauge is increased to 1.5 mm or more to improve structural integrity and reduce magnetic interference, then power reception efficiency is improved, but tire weight and manufacturing complexity increase

Engineering Contradiction:
Improvepower reception efficiencyVSAvoidtire weight
Core Design Contradiction:
Use of energy by moving objectVSWeight of moving object

Solution Approach 1:

The patent specifies a minimum sidewall gauge of 1.5 mm as an optimal parameter that balances multiple requirements: it provides sufficient structural strength, ensures adequate non-magnetic material thickness for magnetic field penetration, and maintains reasonable weight. This parameter optimization resolves the contradiction between efficiency and weight.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The tire is constructed using composite materials with specific non-magnetic properties that allow magnetic field penetration while maintaining structural integrity. The combination of non-magnetic rubber compounds and appropriate sidewall thickness creates a material system that satisfies both power reception efficiency and weight constraints.

Inventive Principle:
Principle #40Composite materials

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

Improves power receiving efficiency by minimizing interference from obstacles and optimizing material composition to enhance magnetic field transmission.

Implementation Method 1

a power reception device attached to an outer peripheral surface of the rim to receive electric power supplied wirelessly from farther outward in a radial direction of the wheel than the rim

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

relay device disposed on an inner peripheral surface side of the rim and connected electrically to the wiring, characterised in that the relay device is configured by a relay coil attached to the inner peripheral surface of the rim

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4005818B1Tire/wheel assembly and tire
Publication Date: 2026.04.01 BRIDGESTONE CORP
  • EP4005818B1 patent drawingFigure 1
  • EP4005818B1 patent drawingFigure 2
  • EP4005818B1 patent drawingFigure 3

AI summary

A tire/wheel assembly includes a wheel including a disk and a rim, the wheel having a power reception device attached to an outer peripheral surface of the rim to receive electric power supplied wirelessly from farther outward in a radial direction of the wheel than the rim, and a tire attached so as to cover an outer peripheral surface of the wheel and including a pair of sidewall portions. A gauge of the sidewall portions is 1.5 mm or more.