Motor Coil-End Metal Cover for Fire and Smoke Containment

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Solution Overview

Problem

Existing motors with resin-covered stators are prone to fire and smoke leakage due to coil shorts, despite safety protection circuits, as the coil ends protruding from the stator core are unprotected and can ignite external fires.

Innovation Solution

A non-combustible layer, made of metal or air, is provided to cover the coil ends and extend in various directions to block fire and smoke from escaping, with additional metallic covers for enhanced protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If coil ends are left protruding for ease of connection, then electrical connectivity is improved, but fire safety deteriorates as coil ends can ignite external fires

Engineering Contradiction:
Improveelectrical connectivityVSAvoidfire safety
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing fire-resistant treatment specifically to the coil ends that protrude from the stator core, while leaving the rest of the coil structure unchanged. This targeted approach maintains electrical connectivity where needed while protecting only the specific areas exposed to fire risk.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces an intermediary fire-resistant material or coating between the coil ends and the external environment. This intermediary layer prevents direct ignition of external combustible materials while allowing electrical connections to function normally through or alongside the protected coil ends.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If molding resin covers the entire stator for protection, then structural integrity is improved, but fire containment deteriorates as resin can crack and allow fire leakage

Engineering Contradiction:
Improvestructural integrityVSAvoidfire containment
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent employs composite materials by combining the molding resin with fire-resistant materials. This could involve coating the resin with fire-resistant layers or incorporating fire-resistant substances into the resin matrix, creating a composite structure that maintains structural integrity while providing fire containment capabilities.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies beforehand cushioning by pre-treating the molding resin or adding fire-resistant layers before fire can occur. This preventive measure ensures that even if the resin cracks under thermal stress, the fire-resistant barrier remains intact to contain any potential fire.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If insulating material covers coil conductors for electrical insulation, then electrical safety is improved, but thermal resistance worsens causing insulating material to melt at high temperatures

Engineering Contradiction:
Improveelectrical safetyVSAvoidthermal resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent uses composite materials by combining insulating materials with heat-resistant substances. This creates a multi-layer or composite insulation structure that maintains electrical insulation properties while withstanding high temperatures without melting, thereby resolving the contradiction between electrical safety and thermal resistance.

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

The non-combustible layer effectively contains fires and smoke within the motor, improving safety and reliability by preventing external leakage even if safety circuits fail.

Implementation Method 1

The non-combustible layer effectively contains fires and smoke within the motor, improving safety and reliability by preventing external leakage

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP3547506B1motor
Publication Date: 2026.03.25 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3547506B1 patent drawingFigure 1
  • EP3547506B1 patent drawingFigure 2~3
  • EP3547506B1 patent drawingFigure 4

AI summary

A motor according to the present invention includes: a stator having a stator core and a coil; a rotor having a rotary shaft and a rotation body; a shaft bearing rotatably supporting the rotor; and a molding resin covering the stator. The motor has a coil end that is the coil protruding from the stator core in a shaft center X direction, and has a non-combustible layer provided to cover the coil end. The non-combustible layer is a metallic cover made of, for example, metal. The metallic cover is disposed to cover a periphery of a coil assembly in which the coil is formed on the stator core through an insulator. The metallic cover is integrated with the coil assembly by a molding resin.