Inductive Vehicle Charging via Ferromagnetic Wheel Rim

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Solution Overview

Problem

Existing methods for charging electric vehicles are complex and inefficient, particularly in contactless energy transmission, which often result in significant energy loss and require close proximity between the primary and secondary conductors.

Innovation Solution

A device utilizing an inductively coupled system where a primary conductor, wound around a U-shaped coil core, transfers energy to a secondary winding on a vehicle's wheel rim, which is ferromagnetic and electrically conductive, allowing for efficient energy transmission over large distances with reduced air gaps and scattering losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If contactless energy transmission is used, then charging convenience is improved, but energy loss increases

Engineering Contradiction:
Improvecharging convenienceVSAvoidenergy loss
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The vehicle body serves as an intermediary conductor between the ground-based primary conductor and the charging system. The vehicle's metallic body naturally present structure is utilized to receive electromagnetic induction from the ground conductor and transfer energy to the charging terminal, eliminating the need for dedicated receiving coils while reducing energy loss through direct conductive path utilization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Length of stationary object

If the distance between primary and secondary conductors is increased, then installation flexibility is improved, but transmission efficiency deteriorates

Engineering Contradiction:
Improvedistance between conductorsVSAvoidtransmission efficiency
Core Design Contradiction:
Length of stationary objectVSLoss of energy

Solution Approach 1:

The vehicle body acts as an extended intermediary that bridges the gap between the ground-based primary conductor and the charging terminal. By utilizing the vehicle's existing metallic structure as a conductive medium, the system maintains efficient energy transfer over larger distances without requiring the secondary conductor to be in close proximity to the primary conductor.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a dedicated secondary winding is installed on the vehicle, then energy reception capability is improved, but device complexity increases

Engineering Contradiction:
Improveenergy reception capabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vehicle body serves multiple functions: it acts as the structural framework, the protective enclosure, and simultaneously as the electromagnetic receiving conductor for wireless charging. This multi-functional utilization eliminates the need for separate dedicated receiving coils or windings, reducing system complexity while maintaining effective energy reception capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Loss of energy

If ferromagnetic material is used for the vehicle body, then magnetic field guidance is improved, but manufacturing cost increases

Engineering Contradiction:
Improvemagnetic field guidanceVSAvoidmanufacturing cost
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The system is designed to work with the existing electromagnetic properties of common vehicle body materials. By optimizing the grounding system and primary conductor configuration, the invention achieves effective energy transfer without requiring special ferromagnetic materials, thus avoiding increased manufacturing costs while maintaining good magnetic field guidance through proper system design.

Inventive Principle:
Principle #35Parameter changes

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 solution enables efficient, contactless energy transfer to electric vehicles with reduced energy losses, allowing for cost-effective production and efficient power delivery, while also enabling data transmission and vehicle identification, thus simplifying the charging process.

Implementation Method 1

a primary conductor (23) can be inductively coupled to an annular part (21) of the vehicle (1), the annular part (21) being rotatably mounted on the vehicle (1)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the ring-shaped part consists of an electrically conductive and ferromagnetic material. The advantage here is that the field flux between the elevations can be guided through the ring-shaped part

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Data Source

PatentEP2603393B1Device for transferring energy to a vehicle without contact, vehicle, and use of a rim of a vehicle
Publication Date: 2017.07.12 SEW EURODRIVE GMBH & CO KG
  • EP2603393B1 patent drawingFigure 1
  • EP2603393B1 patent drawingFigure 2
  • EP2603393B1 patent drawingFigure 3

AI summary

The invention relates to a device for transferring energy to a vehicle without contact, to a vehicle, and to the use of a rim of a vehicle, wherein a primary conductor can be arranged so as to be inductively coupled to an annular part of the vehicle, wherein the annular part is rotatably mounted on the vehicle, in particular on the frame of the vehicle, wherein a secondary winding is arranged on the vehicle so as to be inductively coupled to the annular part.