Insulating Tape with Flat Sheet Layer for Stator Coils

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional insulating tapes for stator coils in rotating electric machines fail to effectively increase thermal conductivity due to filler material flowing out during the hot-pressing process, which compromises the formation of a high thermal conductivity insulating coating.

Innovation Solution

An insulating tape is developed with a mica layer, a reinforcing layer containing a fibrous material and a filler, and a flat sheet layer with specific inorganic particles, which prevents filler flow-out during hot-pressing by creating a barrier that maintains the filler in place, thereby enhancing thermal conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If an insulating tape including a filler exhibiting high thermal conductivity is used to increase the thermal conductivity of the insulating coating, then the thermal conductivity is improved, but the filler flows out through gaps in the insulating tape during hot-pressing, causing the thermal conductivity to be insufficient

Engineering Contradiction:

Improvethermal conductivityVSAvoidfiller flow-out

Core Design Contradiction:

TemperatureVSLoss of substance

Solution Approach 1:

The insulating tape is divided into multiple functional layers: a mica layer (base), a reinforcing layer with filler (thermal conductivity function), and a flat sheet layer (constraint function). This segmentation allows the filler-containing layer to be separated from the constraint function, preventing filler flow-out while maintaining thermal conductivity enhancement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flat sheet layer is formed on the reinforcing layer in advance, creating a barrier structure before the hot-pressing process. This preliminary action prevents the filler from flowing out during subsequent manufacturing steps, ensuring the filler remains in place to provide the desired thermal conductivity.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If the insulating tape is wrapped several times around the coil conductor and impregnated with resin composition under reduced pressure, then the insulating coating is formed, but the filler flows out together with the resin composition during hot-pressing

Engineering Contradiction:

Improveinsulating coating formationVSAvoidfiller flow-out

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The insulating tape structure is segmented into distinct layers with specific functions. The flat sheet layer is separated from the filler-containing reinforcing layer, allowing the tape to be easily wrapped and impregnated while the flat sheet layer prevents filler flow-out during hot-pressing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flat sheet layer acts as an intermediary barrier between the filler-containing reinforcing layer and the external environment. It mediates by preventing filler flow-out while allowing the resin composition to impregnate the structure, thus maintaining ease of manufacture while preventing substance loss.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Temperature

If a filler is supported in advance in the insulating tape, then the thermal conductivity can be increased, but the filler flows out during hot-pressing and the thermal conductivity is not sufficiently increased

Engineering Contradiction:

Improvethermal conductivityVSAvoidthermal conductivity achievement

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The insulating tape is segmented into a reinforcing layer (containing filler for thermal conductivity) and a flat sheet layer (providing constraint). This segmentation ensures the filler is supported in advance while being prevented from flowing out, achieving both high thermal conductivity and reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flat sheet layer is formed in advance on the reinforcing layer to create a barrier structure. This preliminary constraint structure ensures that when the tape is used and subjected to hot-pressing, the filler cannot flow out, thereby achieving the desired thermal conductivity with reliability.

Inventive Principle:

Principle #10Preliminary action

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

The solution effectively forms an insulating coating with improved thermal conductivity, preventing filler flow-out and ensuring the desired thermal performance of the stator coil.

Implementation Method 1

covering a reinforcing layer that is formed on a mica later and contains a filler exhibiting high thermal conductivity with a flat sheet layer containing specific flat sheet-shaped inorganic particles, the filler can be effectively prevented from flowing out

Methodology Applied

Scientific EffectPhysical barrier effect: Physical Containment

Data Source

PatentUS9925744B2Insulating tape, method for producing same, and stator coil

Publication Date: 2018.03.27 MITSUBISHI GENERATOR CO LTD

AI summary

An insulating tape including: a mica layer containing mica; a reinforcing layer that is laminated onto the mica layer and contains a filler and a fibrous reinforcing material; and a flat sheet layer that is laminated onto the reinforcing layer and contains flat sheet-shaped inorganic particles having an aspect ratio of at least 30. In this insulating tape, the filler is supported in advance, and does not therefore flow out during manufacture of a stator coil, for example during hot-pressing. As a result, an insulating coating exhibiting high thermal conductivity can be formed.