Flat Wire Stator Coil Connections Without Cross-Layer Conductors

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Solution Overview

Problem

The existing flat wire motor winding methods require a large variety of hair-pin flat wires, leading to low production efficiency.

Innovation Solution

The flat wire stator design includes an iron core with slots and a winding mode where coils are connected in series, distributed in rotational symmetry around the iron core axis, with first and second ends of the coils located on opposite sides of the iron core slots, reducing the need for additional conductors to cross layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the traditional layer-by-layer winding method is used to form flat wire windings, then the winding can be completed, but a large variety of hair-pin flat wires are required resulting in low production efficiency

Engineering Contradiction:
Improveproduction efficiencyVSAvoidvariety of hair-pin flat wires
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The winding is divided into multiple coils distributed in different iron core slots, with each coil having first and second ends located at opposite sides of the slots. This segmentation allows coils to be connected in series without requiring additional conductors to cross layers, reducing the variety of hair-pin flat wires needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the spatial arrangement by positioning first ends and second ends of coils at opposite sides of iron core slots rather than in the same layer. This dimensional reorganization eliminates the need for conductors to cross layers, thereby reducing the variety of hair-pin flat wires required.

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

2Productivity

If additional conductors are used to cross layers during winding, then layer formation can be completed, but the variety of hair-pin flat wires increases and production efficiency decreases

Engineering Contradiction:
Improveproduction efficiencyVSAvoidvariety of conductors
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

Adjacent coils are connected in series by directly connecting the second end of one coil to the first end of the adjacent coil. This merging of coil ends eliminates the need for separate additional conductors to cross layers, reducing conductor variety and improving production efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of having all coil ends in the same layer requiring cross-layer connections, the patent inverts the arrangement by placing first and second ends at opposite sides of slots. This inversion eliminates the need for additional cross-layer conductors.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP4231506B1Flat wire stator and motor
Publication Date: 2025.06.04 XIAOMI EV TECH CO LTD
  • EP4231506B1 patent drawingFigure 1
  • EP4231506B1 patent drawingFigure 2
  • EP4231506B1 patent drawingFigure 3

AI summary

The disclosure relates to the field of motors, and provides a flat wire stator and a motor. The motor includes an iron core (10) and a flat wire winding (20) including a first phase winding (201), the first phase winding includes a plurality of coils (202) distributed in rotational symmetry around an axis of the iron core, the coils are wound in some iron core slots (10a) of the plurality of iron core slots, and first ends and second ends of the coils are located at the same end of the iron core; and the plurality of coils are connected in series in sequence, the first end of a coil is connected to the first end of one coil of two coils adjacent to the coil, and the second end of the coil is connected to the second end of the other coil of the two coils.