Battery Device Inductive Charging Coil Segmentation

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Solution Overview

Problem

Existing hand-held power tool battery devices with inductive charging units face challenges in achieving compact size and flexible usability due to limitations in the design of inductive charging coils and their integration within the battery device.

Innovation Solution

The use of a primary winding and multiple secondary windings, which are pivotable and partially embedded in a flexible substrate or housing, allows for an adaptable charging surface and efficient energy transfer, with the secondary windings being offset by 120° on the outer circumference of the primary winding, enhancing the effective area of the inductive charging coil.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a conventional inductive charging coil with basic winding is used, then the charging function is achieved, but the base area and overall size of the battery device become too large

Engineering Contradiction:
Improvebase area of battery deviceVSAvoidcharging efficiency
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The inductive charging coil is segmented into a primary winding and multiple secondary windings arranged in a star pattern. This segmentation allows the charging coil to cover a larger effective area while maintaining a compact base footprint, as the secondary windings are distributed around the outer circumference of the primary winding at 120° intervals.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The secondary windings are arranged in a radial pattern around the primary winding, utilizing the circumferential dimension. This dimensional arrangement increases the effective charging area without proportionally increasing the base area, as the windings are distributed around the perimeter rather than extending linearly.

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

2Area of stationary object

If the inductive charging coil is made compact, then the base area is reduced, but the effective charging area and energy transfer efficiency are insufficient

Engineering Contradiction:
Improvebase area of inductive charging coilVSAvoideffective charging area
Core Design Contradiction:
Area of stationary objectVSArea of moving object

Solution Approach 1:

The secondary windings are nested around the outer circumference of the primary winding, with each secondary winding positioned radially outward. This nested arrangement allows the effective charging area to be expanded while maintaining a compact base area, as the windings are layered concentrically rather than requiring additional lateral space.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

At least one secondary winding is made pivotable relative to the primary winding, allowing dynamic adjustment of the charging configuration. This pivotability enables the effective charging area to be adapted to different charging scenarios while maintaining a compact base area when not in use.

Inventive Principle:
Principle #15Dynamics

3Area of moving object

If multiple secondary windings are added around the primary winding, then the effective area is enhanced, but the device complexity increases

Engineering Contradiction:
Improveeffective area of inductive charging coilVSAvoidstructure of inductive charging coil
Core Design Contradiction:
Area of moving objectVSDevice complexity

Solution Approach 1:

The inductive charging coil uses an asymmetric star pattern with one primary winding and multiple secondary windings positioned at 120° intervals. This asymmetric arrangement optimizes the magnetic field distribution for efficient energy transfer while maintaining a relatively simple structural configuration that is easier to manufacture than symmetric multi-coil designs.

Inventive Principle:
Principle #4Asymmetry

4Adaptability or versatility

If the secondary windings are made pivotable, then flexible usability is achieved, but the manufacturing complexity and difficulty increase

Engineering Contradiction:
Improveflexibility of charging configurationVSAvoidmanufacturing of pivotable windings
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The pivotable secondary windings are implemented using flexible printed circuit board (FPC) technology, where the windings are formed as thin flexible conductive traces. This approach enables pivoting motion while maintaining electrical connectivity, and the FPC manufacturing process is well-established and relatively simple compared to traditional rigid coil assemblies with mechanical joints.

Inventive Principle:
Principle #30Flexible shells and thin films

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 results in a compact battery device with a small base area, enabling efficient energy transfer and flexible usage, while maintaining protection and preventing damage through a well-integrated inductive charging unit.

Implementation Method 1

an inductive charging unit (14) for charging the battery cell unit (12), wherein the inductive charging unit (14) has at least one inductive charging coil (18) with at least one basic winding

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3580018B1Battery device
Publication Date: 2021.04.07 ROBERT BOSCH GMBH
  • EP3580018B1 patent drawingFigure 1
  • EP3580018B1 patent drawingFigure 2~3

AI summary

The invention relates to a battery device, having a battery cell unit (12) and at least one inductive charging unit (14) for charging the battery cell unit (12), the inductive charging unit (14) having at least one inductive charging coil (18) having at least one main winding (20). According to the invention, the inductive charging coil (18) has at least one secondary winding (22, 24, 26), the winding axis (28, 30, 32) of which extends at least substantially perpendicularly to a winding axis of the main winding (20).