Armature Winding Insulation via Air Bubble Buffering

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Solution Overview

Problem

In rotary electric machines, the existing methods for ensuring electrical insulation between coils of different phases using interphase insulating papers are prone to misalignment and damage due to vibration, and require a costly varnish impregnation and hardening process.

Innovation Solution

An armature design incorporating a strip-shaped insulating sheet material with an insulating buffering material that forms air bubble groups, which is inserted between conductor portions and fixed without the need for varnish impregnation, ensuring electrical insulation between coils of different phases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If interphase insulating papers are inserted between coils of different phases, then electrical insulation is ensured, but misalignment and damage occur due to vibration during operation

Engineering Contradiction:

Improveelectrical insulationVSAvoidposition stability of insulating paper

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The insulating buffering material is pre-formed on the insulating sheet material before insertion into the coil end, creating a ready-to-fix structure that will engage with the conductor portions upon insertion, preventing subsequent misalignment or damage during operation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The insulating buffering material acts as an intermediary element between the insulating sheet material and the conductor portions, providing a mechanical connection that stabilizes the insulating paper while maintaining electrical insulation functionality

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If varnish is impregnated and hardened in coil ends to fix interphase insulating papers, then electrical insulation is ensured and papers are fixed, but manufacturing costs increase

Engineering Contradiction:

Improveelectrical insulation and fixationVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The varnish impregnation and hardening process is extracted and replaced by the mechanical fixation mechanism of the insulating buffering material, eliminating the need for costly chemical treatment while achieving the same fixation and insulation objectives

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The insulating buffering material provides a simple, cost-effective mechanical solution that replaces expensive varnish treatment, using a disposable-like structural element that achieves fixation without requiring additional chemical processing steps

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If interphase insulating papers are disposed in coil ends without fixation, then manufacturing is simple, but misalignment and damage occur due to vibration

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidelectrical insulation stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The insulating buffering material merges the functions of mechanical fixation and electrical insulation into a single integrated component, allowing the insulating paper to be secured without adding complex fixation mechanisms while maintaining manufacturing simplicity

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The insulating sheet material and insulating buffering material form a composite insulating structure that provides both mechanical stability against vibration and electrical insulation, achieving reliability enhancement without complicating the manufacturing process

Inventive Principle:

Principle #40Composite materials

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 solution provides reliable electrical insulation between coils, reduces manufacturing costs by eliminating the varnish impregnation step, and enhances vibration resistance and rigidity of the armature winding.

Implementation Method 1

an insulating buffering material that is formed on one surface of the insulating sheet material, and that fills between radially adjacent conductor portions so as to have internal air bubble groups

Methodology Applied

Scientific EffectAir bubble formation: Bubble

Data Source

PatentUS9935515B2Armature for rotary electric machine

Publication Date: 2018.04.03 MITSUBISHI ELECTRIC CORP

AI summary

An armature winding is configured by mounting into an armature core a plurality of distributed-winding coils that are each produced by bending and shaping a conductor wire that is coated with insulation, coil ends are configured by arranging coil end portion rows that are formed by arranging coil end portions of the coils in a single row circumferentially in n layers in a radial direction, where n is an integer that is greater than or equal to 1, and an interphase insulating material includes: a strip-shaped insulating sheet material that is inserted inside the coil end portions, and that is disposed so as to extend circumferentially between the coil end portion rows; and an insulating buffering material that is formed on one surface of the insulating sheet material, and that is fixed to the coil end portion rows by forming air bubble groups internally.