Composite Conductor Segment for Compact Low-Resistance Windings

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Solution Overview

Problem

Existing technologies for constructing stator windings in electrical machines face challenges in achieving a compact and efficient design that maximizes conductor fill factor and minimizes electrical resistance.

Innovation Solution

A conductor segment for electrical machine windings is constructed from a preformed stranded wire and two flat wires, which are electrically connected using diffusion welding or brazing solder, and then wrapped with conductive copper foil for enhanced mechanical strength and conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductor wires with covering insulation layer are used to form windings, then the windings can be inserted into stator slots, but the electrical resistance increases and conductivity decreases

Engineering Contradiction:
Improvewinding insertion capabilityVSAvoidelectrical resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The conductor segment is divided into multiple individual conductor elements (first conductor element, second conductor element, etc.) that are arranged adjacently. This segmentation allows the windings to be inserted into stator slots while reducing electrical resistance by providing multiple parallel conduction paths, thereby improving overall conductivity without compromising insertion capability.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If traditional winding construction methods are used, then production can be simplified, but the conductor fill factor is not maximized and mechanical strength is insufficient

Engineering Contradiction:
Improveproduction simplicityVSAvoidconductor fill factor
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The conductor segment combines multiple different conductor elements (round conductor, flat conductor, stranded conductor) with complementary properties into a single composite structure. This allows the segment to achieve high conductor fill factor and mechanical strength while maintaining ease of manufacture through modular assembly into stator slots.

Inventive Principle:
Principle #40Composite materials

3Strength

If conductor segments are constructed from multiple sections, then mechanical strength and conductivity are improved, but the device complexity increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidconductor segment structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Multiple conductor elements with different geometries and properties are merged into a single integrated conductor segment structure. This combining approach enhances mechanical strength and electrical conductivity while presenting a unified component that simplifies handling and installation, effectively balancing improved performance with controlled complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 allows for a compact and efficient winding design with improved mechanical strength and electrical conductivity, enabling the production of high-quality electrical machine components suitable for large-scale production.

Implementation Method 1

a braided wire and two flat wires, which are electrically connected to one another using diffusion welding

Methodology Applied
Scientific EffectDiffusion welding: Diffusion Welding

Implementation Method 2

a braided wire and two flat wires, which are electrically connected to one another using diffusion welding or brazing solder

Methodology Applied
Scientific EffectBrazing: Brazing

Data Source

PatentEP4309268B1Conductor segment for a winding of an electric machine, and manufacturing method for a conductor segment
Publication Date: 2025.06.11 HOFER POWERTRAIN INNOVATION GMBH
  • EP4309268B1 patent drawingFigure 1
  • EP4309268B1 patent drawingFigure 2
  • EP4309268B1 patent drawingFigure 3

AI summary

The present invention relates to a conductor segment (39I) which can be used in a winding of an electric machine. The segment is constructed from a plurality of metallically conductive portions having a shaped strand (50I) as a first portion. Additional portions include a first flat wire (181) and a second flat wire (182) which are electrically conductively connected to the shaped strand via a joining connection in their end regions. The invention also relates to a method for manufacturing the conductor segment. The invention also relates to a motor vehicle comprising a drive train having an electric machine in which at least one of the conductor segments (39I) according to the invention is installed.