Stator Coil Insulation Winding for Shape-Stable Multi-Strand Coils

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Solution Overview

Problem

Multi-strand conductors used in stator coils tend to change shape when bent, causing damage to the insulating material and resulting in uneven coil shapes or protrusions, which complicates repair and integration into stator slots, especially in high-power density motors.

Innovation Solution

A stator coil is formed by winding a conductor with substantially straight sides and opposing curved ends, with insulating material provided between the turns and wound simultaneously with the conductor, either as a flat sheet or U-shaped to maintain shape and reduce distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multi-strand conductors are used to form coils, then power density and current capacity are improved, but the conductor shape changes when bent causing insulation damage and coil deformation

Engineering Contradiction:
Improvepower densityVSAvoidcoil shape consistency
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The conductor is divided into multiple independent strands within a bundle, allowing each strand to flex independently during bending, which reduces the overall shape change and insulation damage of the multi-strand conductor when formed into coils

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the physical parameters of the conductor by using multiple thin strands instead of a single thick conductor, and by controlling the strand arrangement and insulation thickness, to achieve better flexibility and shape consistency during coil formation

Inventive Principle:
Principle #35Parameter changes

2Reliability

If additional insulation layers and protective features (slot liners, end cheeks) are added to protect against insulation damage, then reliability is improved, but device complexity and manufacturing steps increase

Engineering Contradiction:
Improveinsulation protectionVSAvoidcoil structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies a sufficient thickness of insulating material (e.g., 0.5mm to 2mm) beforehand on the conductor strands before coiling, which provides adequate protection against damage during bending and operation, eliminating the need for additional protective layers and simplifying the overall structure

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP4451522A1Stator coil insulation
Publication Date: 2024.10.23 HAMILTON SUNDSTRAND CORP
  • EP4451522A1 patent drawingFigure 1A~2
  • EP4451522A1 patent drawingFigure 3A~3B
  • EP4451522A1 patent drawingFigure 4A~4B

AI summary

A stator coil comprising: a conductor wound into a plurality of turns having substantially straight sides and opposing curved ends; and insulating material provided between the conductor turns and wound into the turns with the conductor, and a method of forming a stator coil, the method comprising: winding a conductor in a plurality of turns defined by opposing substantially straight sides an opposing curved ends, and winding an insulating material located below or above the conductor together with the conductor.