Polymer-Filled Brushed Motor for Explosion Risk Reduction

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Solution Overview

Problem

Existing brushed electric motors cannot be used in environments with a risk of fire or explosion due to spark generation from brushes, and while brushless motors are more suitable, they are complex and costly.

Innovation Solution

A brushed electric motor with a polymer-based filler element to minimize volume and risk of fire, incorporating sliding contacts, a metallic external case for grounding, and a printed circuit board with integrated components to reduce noise and electromagnetic interference, along with a noise suppression device to prevent sparking and dust accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a brushed electric motor is used, then the structure is simple and cost is low, but sparks are generated causing fire or explosion risk in hazardous environments

Engineering Contradiction:
Improvemotor structure complexityVSAvoidfire or explosion risk
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful sparks generated by brushes into a beneficial effect by filling the free volume with polymer material. This prevents spark propagation and eliminates fire/explosion risk while maintaining the simple brushed motor structure, thus converting a harmful characteristic into a safety feature.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The polymer filler material creates an inert environment within the motor by displacing air and preventing oxygen contact with sparks. This inert atmosphere suppresses combustion and eliminates the fire hazard associated with traditional brushed motors in hazardous locations.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If a brushless motor is used, then fire or explosion risk is reduced, but the structure becomes more complex and cost increases

Engineering Contradiction:
Improvefire or explosion riskVSAvoidmotor structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts only the essential safety feature from brushless motors (elimination of sparks) while retaining the simple brushed motor structure. By filling the free volume with polymer material, it achieves spark suppression without adopting the complex brushless construction, thus extracting the safety benefit while avoiding the complexity penalty.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses composite polymer filler material that combines multiple functions: volume displacement, spark suppression, and structural support. This composite approach achieves brushless-level safety while maintaining brushed motor simplicity and cost-effectiveness.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If the free volume within the motor is reduced, then the risk of fire or explosion is minimized, but the motor volume and performance may be affected

Engineering Contradiction:
Improvefire or explosion riskVSAvoidmotor power
Core Design Contradiction:
Object-affected harmful factorsVSPower

Solution Approach 1:

The patent applies local quality by filling only the free volume spaces within the motor housing with polymer material, while leaving the functional components (stator, rotor, brushes) unchanged. This localized approach minimizes fire risk without affecting the motor's power-generating components, thus maintaining full power output.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The polymer filler material serves multiple functions simultaneously: it displaces air to prevent combustion, provides structural support, and maintains the motor's dimensional stability. This multi-functionality allows free volume reduction without compromising motor performance or requiring additional components.

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

Enables the use of brushed electric motors in hazardous environments with reduced noise, lower electromagnetic emissions, and extended lifespan, while maintaining high performance and reducing the risk of fire or explosion, without the need for a brushless motor.

Implementation Method 1

at least one filler element 20 made with a polymer based material which is positioned internally to said brushed electric motor 10, for minimizing the free volume within said brushed electric motor 10 itself

Methodology Applied
Scientific EffectVolume minimization:

Implementation Method 2

said external case 11 allows in part to absorb any possible electric strokes through a grounding electric connection

Methodology Applied
Scientific EffectGrounding: Earthing

Implementation Method 3

for allowing at the same time to maintain high power and great performance characteristics of said brushed electric motor 10, so advantageously minimizing the possibility of triggering of a burst or fire

Methodology Applied
Scientific EffectCombustion prevention:

Data Source

PatentEP3121941B1Brushed electric motor
Publication Date: 2024.12.11 INT POWER COMPONENTS SRL
  • EP3121941B1 patent drawingFigure 1~2
  • EP3121941B1 patent drawingFigure 3
  • EP3121941B1 patent drawingFigure 4

AI summary

Brushed electric motor (10), comprising an outer case (11), two brushes and further a rotor (30) having a first inner end (31) and a second outer end (32) which is inserted within the outer case (11). The brushed electric motor (10) is in particular usable in environments with a risk of fire or explosion or in presence of potentially explosive or flammable fluids, and comprises at least a filler element (20) made with a polymer based material which is positioned internally to the outer case (11) of said brushed electric motor (10) for minimize the free volume within the brushed electric motor (10) itself and for allow at the same time to maintain a high power and high performance characteristics of the brushed electric motor (10), by minimizing the possibility of triggering a burst or fire.