Motor Encoder Emissivity for Passive Thermal Management

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Solution Overview

Problem

Electric motor components often overheat due to inadequate thermal management, leading to reduced performance and potential failure, with existing solutions like fans and liquid cooling systems being costly and space-intensive.

Innovation Solution

Increasing the emissivity of internal motor components, such as the encoder and end cap, by applying black paint or anodizing to enhance radiational heat transfer from the interior to the exterior of the motor housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fans are provided for circulating air to remove excess heat, then heat dissipation is improved, but cost and device complexity increase

Engineering Contradiction:

Improveheat dissipationVSAvoiddevice complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent extracts the active cooling mechanism (fan) and replaces it with a passive radiative cooling approach using high-emissivity coatings on internal surfaces, thereby eliminating the need for moving parts while maintaining heat dissipation effectiveness

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical cooling system (fan-driven air circulation) with a thermal radiation-based system using selective surface coatings, substituting mechanical action with electromagnetic radiation principles

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If externally mounted heat sinks are provided to transfer heat to the exterior, then heat dissipation is improved, but additional space is required

Engineering Contradiction:

Improveheat dissipationVSAvoidadditional space

Core Design Contradiction:

TemperatureVSArea of stationary object

Solution Approach 1:

The patent nests the heat dissipation function within the existing motor housing structure by applying high-emissivity coatings to internal surfaces, allowing the housing to serve dual purposes as both structural enclosure and thermal radiation surface

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent shifts the heat dissipation approach from external attachment (adding space in one dimension) to internal surface treatment (utilizing the existing three-dimensional space more effectively through surface property modification)

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Temperature

If liquid cooling systems are provided, then heat dissipation is improved, but cost and device complexity increase significantly

Engineering Contradiction:

Improveheat dissipationVSAvoiddevice complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex liquid cooling system entirely, replacing it with a simple passive radiative cooling approach that requires no pumps, tubes, or fluid management infrastructure

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a simple, inexpensive high-emissivity coating that can be applied directly to internal surfaces, replacing expensive and complex liquid cooling infrastructure with a low-cost surface treatment

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

4Temperature

If motor torque is reduced at high RPMs to lower heat output, then operating temperature is controlled, but productivity decreases

Engineering Contradiction:

Improveoperating temperatureVSAvoidproductivity

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The patent converts the harmful heat generated by high-speed operation into a beneficial signal by using high-emissivity surfaces to radiate this heat away, allowing the motor to operate at full power without thermal damage

Inventive Principle:

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

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 effectively increases heat dissipation, improving motor performance by maintaining lower internal temperatures without the need for additional space or high-cost cooling systems.

Implementation Method 1

radiation heat transfer of electric motor components

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 2

the interior surface of the end cap can be anodized black. The interior surface of the end cap can be painted black

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS10566878B2Radiation heat transfer of internal motor components by electro-magnetic waves

Publication Date: 2020.02.18 ROCKWELL AUTOMATION TECH INC

AI summary

A motor assembly including a housing with a motor portion having an opening for receiving a motor housing/stator assembly, rotor assembly, front and rear end caps and bearings, an encoder coupled to the motor, and an rear cover for enclosing the opening of the motor portion of the housing, the rear cover at least partially surrounding the encoder. At least one of an interior surface of the rear cover or an exterior surface of the encoder comprise a material having an emissivity greater than 0.9.