Nine-Tooth Stator Winding Layout With Fewer Crimp Connections

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Solution Overview

Problem

Existing electric motors with windings wound on the teeth of an iron core require numerous winding connections, increasing manufacturing time and cost.

Innovation Solution

An electric motor design featuring a cylindrical stator with an iron core and nine teeth, where three independent windings are wound continuously on different teeth, connected using first and second crimp terminals to reduce connection points, and a manufacturing method that winds the windings in a specific order to facilitate efficient assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If resin is injected into the stator core using conventional methods, then the stator core becomes saturated with resin, but the resin penetrates into the slot portion and causes leakage flux that increases iron loss

Engineering Contradiction:
Improveresin saturation uniformityVSAvoidiron loss
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The stator core is divided into distinct regions: the tooth portion is fully saturated with resin while the slot portion remains unsaturated. This segmentation allows selective resin penetration controlled by the resin blocking member, ensuring resin saturation uniformity without causing leakage flux in the slot region, thereby reducing iron loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A resin blocking member is introduced as an intermediary component between the resin injection system and the stator core slots. This blocking member prevents resin from penetrating into the slot portion while allowing complete saturation of the tooth portion, thus eliminating the harmful leakage flux without compromising manufacturing saturation uniformity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If manual resin injection is used, then resin application is possible, but labor cost increases and productivity decreases

Engineering Contradiction:
Improveresin injection capabilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The resin injection system is designed to automatically inject resin into the stator core through injection holes without requiring manual intervention. The system self-regulates resin flow and saturation levels, eliminating labor-intensive manual injection processes while maintaining complete resin penetration into the tooth portion, thus improving productivity without sacrificing manufacturing capability.

Inventive Principle:
Principle #25Self-service

3Reliability

If resin penetrates into the slot portion, then slot insulation is improved, but leakage flux increases and iron loss increases

Engineering Contradiction:
Improveslot insulationVSAvoidiron loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Different regions of the stator core are given different resin saturation qualities: the tooth portion receives complete resin saturation for structural stability, while the slot portion is deliberately kept unsaturated to prevent leakage flux. This local quality differentiation ensures that insulation reliability is maintained where needed without causing harmful electromagnetic effects.

Inventive Principle:
Principle #3Local quality

4Device complexity

If the stator core structure is simplified without a resin blocking member, then device complexity decreases, but resin control precision is lost

Engineering Contradiction:
Improvestator core structureVSAvoidresin penetration control
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

Instead of using a complex three-dimensional resin blocking member, the invention employs a simple two-dimensional resin blocking plate that copies the essential blocking function. This plate is inserted into the air gap and effectively prevents resin from reaching the slot portion while maintaining simple stator core structure, thus achieving both low device complexity and high resin penetration control precision.

Inventive Principle:
Principle #26Copying

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

Reduces the number of connection points, thereby decreasing manufacturing time, effort, and cost, while allowing for smoother assembly and reduced material usage.

Implementation Method 1

a resin blocking member that is inserted into an air gap between a stator core and a rotor core in an axial direction of the rotor core, blocks resin for infiltrating the air gap and a slot portion

Methodology Applied
Scientific EffectPhysical barrier blocking:

Implementation Method 2

resin is injected into a stator core from resin injection holes formed in both side surfaces of the stator core in a radial direction of the stator core with use of an injection needle

Methodology Applied
Scientific EffectPressure injection:

Data Source

PatentEP4007127B1Electric motor, compressor, refrigeration circuit device, and manufacturing method for electric motor
Publication Date: 2026.05.06 CARRIER JAPAN CORP
  • EP4007127B1 patent drawingFigure 1
  • EP4007127B1 patent drawingFigure 2
  • EP4007127B1 patent drawingFigure 3

AI summary

An electric motor according to an embodiment includes a stator and a rotor. The stator includes an iron core including a cylindrical yoke and nine teeth protruding inwardly of the yoke, an insulating member provided at an end portion in an axial direction of the iron core, three independent windings respectively wound continuously on three different teeth of the nine teeth, three first crimp terminals provided respectively to the three windings, and three second crimp terminals provided respectively to the three windings. Each of the three windings includes a first terminal wire, a second terminal wire, a first intermediate wire between two teeth close to the second terminal wire, and a second intermediate wire between two teeth close to the first terminal wire. The first crimp terminal connects the first terminal wire of the corresponding winding to two points of the first intermediate wire of the winding. The second crimp terminal connects the second terminal wire of the corresponding winding to two points of the second intermediate wire of the winding.