Stator Resin Coating Amorphous Deformation

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Solution Overview

Problem

Conventional stator manufacturing methods face issues with cracks in the extruded resin coating layer due to its crystalline state during deformation, leading to insulation failures, and the enamel layer alone cannot provide sufficient insulation at coil end portions, necessitating the use of additional insulation interphase sheets, which increases costs.

Innovation Solution

The method involves deforming the insulated conductor coil while the extruded resin coating layer is in an amorphous state and then heating it to a crystalline state, ensuring the coil end portions remain amorphous to prevent cracking and the in-slot portions are heated to a crystalline state for enhanced insulation, using techniques like induction heating or laser heating to control the resin state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the extruded resin coating layer is in a crystalline resin state during deformation, then the insulation property is improved, but cracks occur in the coating layer

Engineering Contradiction:
Improveinsulation propertyVSAvoidcrack resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies parameter changes by controlling the thermal state of the extruded resin coating layer. The coating layer is heated to transition from a crystalline state (high rigidity, good insulation) to an amorphous state (low rigidity, high flexibility) during deformation, then re-heated after deformation to restore the crystalline state. This temporal parameter change resolves the contradiction between insulation property and crack resistance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses preliminary action by heating the extruded resin coating layer to an amorphous state before deformation occurs. This preliminary state change prepares the material to be flexible and crack-resistant during the upcoming deformation process, preventing cracks while maintaining the ability to achieve good insulation after the process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the enamel layer thickness is increased to prevent partial discharge degradation, then insulation reliability is improved, but air bubbles are left in the layer due to volatilization

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidbubble-free coating
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies composite materials by combining the enamel layer with an extruded resin coating layer. The enamel layer provides base insulation, while the extruded resin coating layer (using thermoplastic resin) provides additional insulation and surge resistance. This composite structure achieves the required insulation reliability without requiring excessive enamel layer thickness that would cause bubbling.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the number of bakings is increased to achieve sufficient coating thickness, then insulation property is improved, but contact strength between conductor and enamel layer deteriorates

Engineering Contradiction:
Improveinsulation propertyVSAvoidcontact strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses composite materials by combining the enamel layer with an extruded resin coating layer. This composite insulation structure achieves the required total insulation thickness and insulation property without requiring multiple baking cycles of the enamel layer alone, thereby preserving the contact strength between the conductor and enamel layer.

Inventive Principle:
Principle #40Composite materials

4Reliability

If insulation interphase sheet is used to ensure insulation at coil end portions, then insulation reliability is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by making the extruded resin coating layer serve multiple functions simultaneously: it provides insulation, inverter surge resistance, and crack resistance during deformation. This multi-functional coating eliminates the need for separate insulation interphase sheets at coil end portions, reducing manufacturing complexity while maintaining insulation reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 approach prevents cracks in the resin coating layer during deformation and maintains sufficient insulation properties, reducing the thickness decrease of the extruded resin coating layer by 2% or less, thereby enhancing breakdown voltage and heat resistance.

Implementation Method 1

heating the extruded resin coating layer to a temperature higher than or equal to a glass transition temperature to render the extruded resin coating layer into the crystalline resin state

Methodology Applied
Scientific EffectPhase transition (amorphous to crystalline): Phase Change

Implementation Method 2

heating the extruded resin coating layer to a temperature higher than or equal to a glass transition temperature

Methodology Applied
Scientific EffectGlass transition:

Implementation Method 3

using techniques like induction heating or laser heating to control the resin state

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 4

using techniques like induction heating or laser heating to control the resin state

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP2536005B1Stator manufacturing method and stator
Publication Date: 2020.05.06 TOYOTA JIDOSHA KK
  • EP2536005B1 patent drawingFigure 1
  • EP2536005B1 patent drawingFigure 2A~2D
  • EP2536005B1 patent drawingFigure 3~4

AI summary

A stator manufacturing method which manufactures an insulated conductor coil (100) and mounts the insulated conductor coil (100) to the core, the insulated conductor coil (100) being formed by deforming an insulated conductor (11) into a shape having rectilinear in-slot conductor sections (11B) and coil end sections (11A) having bent sections, the insulated conductor (11) having an enamel layer formed on the outer periphery thereof and also having an extruded resin coating layer formed on the outer periphery of the enamel layer. The method comprises: a first step in which, while the extruded resin coating layer of the insulated conductor (11) is in a non-crystalline resin state, the insulated conductor (11) is deformed to form the bent sections, thereby forming the insulated conductor coil (100); a second step in which the extruded resin coating layer of the insulated conductor coil (100) is changed into a crystalline resin state by heating the extruded resin coating layer to a temperature higher than or equal to the glass transition temperature; and a third step in which the insulated conductor coil (100) is mounted to the core.