Stator Coil End Layout With Axial Overlap to Prevent Conductor Interference

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Solution Overview

Problem

The challenge of downsizing a stator while avoiding interference between segment conductors in a rotating electrical machine is hindered by the limited bending radius of rectangular wire conductors and increased axial length of coil end portions.

Innovation Solution

The stator design includes a configuration where the second connecting portion is positioned closer to the axial second side than the first, with overlapping first and second connecting portions, and varying extension angles to minimize radial and axial dimensions, thereby avoiding interference between segment conductors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the stator core is downsized to reduce the rotating electrical machine size, then the overall machine size is reduced, but the bending radius of segment conductors must be reduced which causes interference between adjacent segment conductors at connecting portions

Engineering Contradiction:
Improvestator core sizeVSAvoidinterference between segment conductors
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a new spatial dimension by allowing connecting portions to overlap in the axial direction. Instead of arranging connecting portions only in the radial direction, the invention utilizes the axial dimension to create overlapping regions, thereby resolving the interference problem while maintaining compact stator core dimensions.

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

Solution Approach 2:

The patent implements nesting by placing one connecting portion inside or overlapping with another connecting portion in the axial direction. This nested arrangement allows multiple segment conductors to share the same radial space at different axial positions, eliminating interference while maintaining small bending radii.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Object-affected harmful factors

If the height from axial end face to vertex of connecting portion is increased to suppress interference, then interference between segment conductors is reduced, but the axial length of coil end portion increases which hinders downsizing

Engineering Contradiction:
Improveinterference between segment conductorsVSAvoidaxial length of coil end portion
Core Design Contradiction:
Object-affected harmful factorsVSLength of moving object

Solution Approach 1:

The patent resolves this contradiction by shifting the solution from increasing vertical height to utilizing axial overlap. Instead of raising the vertex height in the radial direction, the invention allows connecting portions to overlap in the axial direction, thereby suppressing interference without increasing the axial length of coil end portions.

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

Solution Approach 2:

The patent employs dynamic spatial arrangement where connecting portions are positioned at different axial locations rather than maintaining a fixed hierarchical arrangement. This dynamic positioning allows connecting portions to overlap in the axial direction, achieving interference suppression with compact dimensions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4447280B1stator
Publication Date: 2026.04.01 AISIN CORP
  • EP4447280B1 patent drawingFigure 1
  • EP4447280B1 patent drawingFigure 2~3
  • EP4447280B1 patent drawingFigure 4

AI summary

A first-phase coil (1) includes a first connecting portion (15) and a second connecting portion (16) that is disposed closer to an axial second side (L2) than the first connecting portion and overlaps the first connecting portion in axial view. The first connecting portion (15) includes a first circumferential region (E1), a second circumferential region (E2), and a connecting region (E3). In the first circumferential region (E1), a first bent portion (17) is formed between a first section (K1) and a second section (K2) on a connecting region (E3) side, and the extension angle of the second section (K2) is larger than the extension angle of the first section (K1). In the second circumferential region (E2), a second bent portion (18) is formed between a fourth section (K4) and a third section (K3) on the connecting region (E3) side, and the extension angle of the third section (K3) is larger than the extension angle of the fourth section (K4).