Wheel-Mounted Relay Coil Layout for Efficient Vehicle Power Reception

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Solution Overview

Problem

Existing contactless power supply systems face challenges in improving power transfer efficiency due to wide intervals between power transmission and reception coils.

Innovation Solution

The power reception apparatus is configured with a relay coil on a tire wheel, comprising a first coil outside the tire and a second coil inside the wheel, connected by electrical conductors, allowing for narrower intervals between the coils, enhancing power transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a single power reception coil is used in existing contactless power supply systems, then the structure is simple, but the interval between the power transmission coil and the power reception coil is wide, reducing power transfer efficiency

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoidcoil structure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The relay coil is divided into a first coil and a second coil that are arranged at different radial positions on the tired wheel. The first coil is arranged inside the tire closer to the power transmission coil, while the second coil is arranged outside the tire closer to the power reception coil. This segmentation allows each coil to be positioned optimally for its specific function, reducing the overall interval and improving power transfer efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first coil acts as an intermediary between the power transmission coil and the second coil. It receives electromagnetic energy from the power transmission coil and transfers it to the second coil, which then transfers it to the power reception coil. This intermediate relay coil structure enables more efficient power transfer by reducing the direct interval between transmission and reception coils.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the power reception coil is positioned closer to the power transmission coil to improve power transfer efficiency, then the power supply efficiency increases, but the installation space requirements and structural complexity increase

Engineering Contradiction:

Improvepower supply efficiencyVSAvoidinstallation space

Core Design Contradiction:

ProductivityVSVolume of moving object

Solution Approach 1:

The relay coil structure utilizes the radial dimension of the tired wheel by arranging the first and second coils at different radial positions. The first coil is positioned inside the tire at a smaller radial distance from the central axis, while the second coil is positioned outside the tire at a larger radial distance. This three-dimensional arrangement optimizes power transfer efficiency while accommodating the physical constraints of the vehicle undercarriage space.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Loss of energy

If the first coil is arranged inside the tire and the second coil is arranged outside, then the interval to power transmission and reception coils is reduced, but the relay coil structure becomes more complex

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoidrelay coil structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The relay coil assembly serves multiple functions: the first coil receives electromagnetic energy from the power transmission coil, the electrical conductor connects and transfers energy to the second coil, and the second coil transfers energy to the power reception coil. This multi-functional integrated structure achieves improved power transfer efficiency while managing the complexity through functional consolidation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enables improved power transfer efficiency by minimizing coil intervals and reducing electromagnetic field leakage, while reducing installation space and maintaining consistent power reception.

Implementation Method 1

a relay coil that is arranged on a tired wheel, which includes a tire and a wheel, and includes a first coil and a second coil... configured to receive electric power from a power transmission coil embedded in the ground

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS12600248B2Power reception apparatus with relay coils arranged on tired wheel of vehicle

Publication Date: 2026.04.14 DENSO CORP

AI summary

A power reception apparatus is installable in a vehicle and configured to receive electric power from a power transmission coil embedded in the ground. The power reception apparatus includes: a relay coil that is arranged on a tired wheel, which includes a tire and a wheel, and includes a first coil and a second coil; a power reception coil; and a power reception circuit. The first coil and the second coil are connected with each other by an electrical conductor. The first coil is arranged inside the tire. The second coil is located so that a distance from a central axis of the tired wheel to the second coil is shorter than a distance from the central axis to the first coil. The power reception coil is located so that when the first coil faces the power transmission coil, the power reception coil faces the second coil.