Electric Motor Stator Insulation Sheet Nesting

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Solution Overview

Problem

Conventional electric motor stators face inefficiencies due to a gap generated between the insulation sheet and the winding caused by the thickness of the insulator, which reduces the space for winding and hinders further improvements in motor efficiency.

Innovation Solution

The electric motor stator design features an insulation sheet inserted into grooves and gaps within the insulator, eliminating the need for additional space between the winding and the stator core, ensuring proper insulation and allowing for reduced size while maintaining output efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an insulator is used to sandwich both ends of an insulation sheet, then the insulation distance between stator core and winding is maintained, but a step is generated between the insulator and insulation sheet due to the thickness of the insulator

Engineering Contradiction:
Improveinsulation distanceVSAvoidstep generation
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The insulation sheet is inserted into the insulator, with the insulator having an inner diameter larger than the outer diameter of the insulation sheet. This nesting configuration allows the insulation sheet to be positioned inside the insulator, eliminating the step that was previously generated between the insulator and insulation sheet surfaces.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If an insulator with thickness is used to maintain insulation distance, then electrical insulation is ensured, but the space where the winding is wound around is reduced by the amount corresponding to the thickness of the insulator

Engineering Contradiction:
Improveelectrical insulationVSAvoidwinding space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The insulation sheet is nested inside the insulator, allowing the winding to be wound around the outer circumference of the insulator. This configuration eliminates the need for additional space that would have been required if the insulation sheet were positioned outside the insulator, thereby increasing the effective winding space while maintaining electrical insulation.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the insulation sheet is fixed to the teeth portion by the insulator, then insulation is provided, but a gap corresponding to the thickness of the insulator is generated between the insulation sheet and the winding

Engineering Contradiction:
ImproveinsulationVSAvoidmotor efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The insulation sheet is inserted into the insulator, eliminating the gap that was previously generated between the insulation sheet and the winding. This nested configuration allows the winding to be positioned closer to the stator core, improving motor efficiency by increasing the effective use of the available space.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3176915B1Stator for electric motor
Publication Date: 2020.12.09 MITSUBISHI ELECTRIC CORP
  • EP3176915B1 patent drawingFigure 1
  • EP3176915B1 patent drawingFigure 2~3
  • EP3176915B1 patent drawingFigure 4~5

AI summary

An electric motor stator includes a stator core (1) that is constituted by stacking a plurality of silicon steel plates and has a teeth portion (1a), a teeth-tip portion (1b), and a yoke portion (1c), an insulator (4) provided at both axial ends of the stator core (1), an insulation sheet (3) attached to the stator core (1), and a winding wound around the stator core (1) to which the insulator (4) and the insulation sheet (3) are attached. A surface of the insulator (4), on which the winding (2) is wound, is provided with a groove (4a4, 4c11) into which an end of the insulation sheet (3) attached to a surface of the stator core (1), on which the winding (2) is wound, is inserted.