Inductor Bobbin with Segmented Channels for Bare Wire Winding

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Solution Overview

Problem

High power inductors face challenges with insulated wire, which increases stiffness, diameter, and heat dissipation issues, particularly when winding around toroidal cores, due to the added insulation material, making it difficult to bend and assemble efficiently.

Innovation Solution

An electrically insulating bobbin with helical channels is used to wrap uninsulated wire around the inductor core, providing electrical insulation between turns and the core, made from thermally conductive materials like Ultem resin, allowing for compact design and improved heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulated wire is used to electrically isolate phases and wire from core, then electrical insulation is achieved, but wire stiffness increases making it difficult to bend

Engineering Contradiction:
Improveelectrical insulationVSAvoidwire flexibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The insulating function is segmented from the wire and transferred to the bobbin structure. The bobbin is divided into multiple channels, each with insulating floors and walls that provide electrical isolation. This allows the wire itself to remain flexible and uninsulated, while the bobbin provides the necessary electrical insulation through its segmented channel structure.

Inventive Principle:
Principle #1Segmentation

2Reliability

If insulated wire is used to provide electrical insulation, then electrical isolation is achieved, but the total diameter of the wire increases making the inductor larger

Engineering Contradiction:
Improveelectrical insulationVSAvoidinductor size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The insulating material is extracted from the wire and relocated to the bobbin structure. The wire is used in its bare, uninsulated state, maintaining minimal diameter. The bobbin's channel walls and floors provide the electrical insulation function, effectively separating the insulating function from the conductor and optimizing the overall inductor dimensions.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If insulated wire is used to electrically isolate wire from core, then electrical insulation is achieved, but heat dissipation ability is reduced

Engineering Contradiction:
Improveelectrical insulationVSAvoidheat dissipation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The bobbin acts as an intermediary structure that provides electrical insulation without impeding thermal management. The bobbin material (e.g., Ultem resin) provides electrical isolation between wire turns and from the core, while its thermally conductive properties enable efficient heat dissipation. The wire sits in direct thermal contact with the thermally conductive bobbin, facilitating heat transfer away from the wire.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If insulated wire is used for winding, then electrical insulation is provided, but friction between wire turns increases making winding more difficult

Engineering Contradiction:
Improveelectrical insulationVSAvoidwinding process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The bobbin is segmented into discrete channels with defined geometries that guide the wire through the winding process. Each channel acts as a separate pathway, reducing wire-to-wire contact and friction. The wire is confined to its designated channel, making the winding process more controlled and less friction-intensive compared to loose insulated wire.

Inventive Principle:
Principle #1Segmentation

5Reliability

If insulated wire is used to isolate phases, then electrical insulation is achieved, but the wire bulges out from the core increasing outer diameter

Engineering Contradiction:
Improveelectrical insulationVSAvoidouter diameter
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The electrical insulation is moved from a radial dimension (wire insulation adding to wire diameter) to a structural dimension defined by the bobbin channels. The channels provide precise geometric confinement, ensuring the wire maintains a consistent position and the inductor achieves a compact, predictable outer diameter without wire bulging.

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

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

The solution enables easier winding and assembly of high power inductors, reduces size and weight, and enhances heat dissipation by eliminating insulation, resulting in a more efficient and compact inductor design.

Implementation Method 1

made from thermally conductive materials like Ultem resin, allowing for compact design and improved heat dissipation

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2061043B1Inductor bobbin
Publication Date: 2012.04.11 HAMILTON SUNDSTRAND CORP
  • EP2061043B1 patent drawingFigure 1
  • EP2061043B1 patent drawingFigure 2
  • EP2061043B1 patent drawingFigure 3

AI summary

An electrically insulating bobbin (110, 120) surrounds the magnetic core (130) of an inductor (100). The bobbin includes a number of channels to receive wire (140) for making an inductor. When wire is positioned in the channels, the wire is wound around the inductor core, but insulated from the inductor core and the other turns of wire. Because the bobbin insulates the turns of wire from each other and from the inductor core, bare rope wire can be used to wrap the inductor, resulting in reduced size and weight and improved ease of manufacture.