Segmented Coil Body Insulation for Rotary Machine Slot Fill

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing insulation methods for dynamoelectric machines with concentrated windings, such as tooth coils, are inadequate for providing sufficient insulation between the coil and the stator's laminated core, particularly in the axial direction, which limits the copper fill factor and machine performance.

Innovation Solution

A coil body design with two parts per tooth, where one part snaps into the recess of the axial partial laminations and the other into a notch in the first part, ensuring sufficient insulation without reducing the slot cross-sectional area or impairing magnetic conductivity, thus maintaining a high copper fill factor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional insulation methods are used between the coil and stator core, then insulation is provided, but the slot cross-sectional area is reduced and copper fill factor decreases

Engineering Contradiction:
Improveinsulation between coil and stator coreVSAvoidslot cross-sectional area
Core Design Contradiction:
ReliabilityVSArea of moving object

Solution Approach 1:

The coil former is divided into two separate parts: a first part that engages in the recess of the axial partial lamination stack, and a second part that engages in a notch of the first part. This segmentation allows the insulation structure to be optimized without unnecessarily filling the slot cross-section, thereby maintaining the copper fill factor while providing sufficient insulation between the coil and the grounded tooth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coil former parts overlap in the axial direction of the tooth, with the second part engaging in a notch of the first part. This axial dimension arrangement provides sufficient insulation coverage along the axial path of the tooth without occupying excessive radial or circumferential space in the slot cross-section, thus resolving the contradiction between insulation effectiveness and slot area utilization.

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

2Reliability

If insulating material is placed between coil and tooth, then insulation is achieved, but magnetic conductivity of the partial laminated core is impaired

Engineering Contradiction:
Improveinsulation between coil and toothVSAvoidmagnetic conductivity
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The coil former is designed to engage specifically in the recess of the axial partial lamination stack and in a notch of the first part, providing insulation only where electrically necessary (between the coil and the grounded tooth) while leaving the magnetic path through the laminated core substantially uninterrupted. This localized insulation approach maintains magnetic conductivity in the core while providing adequate electrical insulation.

Inventive Principle:
Principle #3Local quality

3Reliability

If overlapping coil former parts are used to prevent leakage currents, then insulation is improved, but slot cross-section is restricted

Engineering Contradiction:
Improveprevention of leakage currentsVSAvoidslot cross-section
Core Design Contradiction:
ReliabilityVSArea of moving object

Solution Approach 1:

The overlapping of the two coil former parts is arranged in the axial direction of the tooth, with the second part engaging in a notch of the first part. This axial arrangement prevents leakage currents along the axial path while minimizing the occupation of the slot cross-sectional area, as the overlap occurs primarily in the axial dimension rather than radially or circumferentially within the slot.

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

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 design enhances the performance of the dynamoelectric machine by maintaining the slot cross-sectional area and copper fill factor, while providing effective insulation to prevent leakage currents, making it suitable for drives in machine tools, e-mobility, and electric trains.

Implementation Method 1

the first part of the coil body of a tooth engages in the recess of the axial partial lamination stack, and wherein the second part of the coil body of this tooth engages in a notch of the first part of the coil body

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Implementation Method 2

insulating material is provided at least between the coil and the respective tooth... to prevent leakage currents

Methodology Applied
Scientific EffectElectrical Insulation: Dielectric

Implementation Method 3

a stator equipped with a winding system that, during operation of the dynamoelectric machine, interacts electromagnetically with a rotor, thus providing a torque at a drive shaft

Methodology Applied
Scientific EffectElectromagnetic Interaction: Electromagnetic Induction

Data Source

PatentEP2882080B1Dynamo-electric rotary machine
Publication Date: 2021.02.17 SIEMENS AG
  • EP2882080B1 patent drawingFigure 1~3
  • EP2882080B1 patent drawingFigure 4~5

AI summary

The invention relates to a rotary motor (1) having a stator (3) which is provided with a winding system (6) positioned in a groove, a rotor (4) magnetically activated or electrically energized and isolated from the stator through an air gap (13). The rotor rotates around an axis due to electromagnetic interaction with the stator. The stator has a plurality of teeth each having axially laminated sheets and thus forming partial stacks, wherein the teeth of the stator (3) points to the air gap (13). Each of the partial laminations of the teeth has two axial end faces, wherein the teeth are respectively surrounded by coils (23). Insulation materials are provided at least between the coils and the respective teeth, wherein the insulation materials are formed as a coil body (12) consisting of two parts per tooth. The two parts start from the respective end sides of the respective tooth to overlap at least an axial portion of the laminated core part of the tooth, especially the side walls of that tooth.