Anisotropic Thermal Composite for Electric Motor Stator Slots

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Solution Overview

Problem

Thermally conductive materials used in electrical devices often exhibit electrical conductivity, leading to risks of electrical shorts and parasitic behaviors that interfere with device functioning, as they also fail to effectively manage heat buildup without these issues.

Innovation Solution

A composite material is developed with a matrix material and thermally conductive, anisotropically electrically oriented additive particles, such as graphene flakes, aligned within a stator slot of an electric motor using an electromagnetic field to enhance thermal conductivity while minimizing electrical conductivity, thereby reducing the risk of electrical shorts and parasitic interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If thermally conductive materials are used to transport thermal energy, then thermal management is improved, but electrical conductivity increases causing electrical shorts and parasitic behaviors

Engineering Contradiction:

Improvethermal energy transportVSAvoidelectrical short risk

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent uses a composite material consisting of a polymer matrix combined with thermally conductive particles (such as aluminum oxide, aluminum nitride, or boron nitride). This composite structure provides thermal conductivity while the polymer matrix maintains electrical insulation properties, thus preventing electrical shorts while enabling effective heat transport from power semiconductor devices.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies different material properties in different directions by creating an anisotropic composite structure. The thermally conductive particles are oriented or distributed to provide enhanced thermal conductivity in specific directions (particularly from the device to the heat sink), while maintaining electrical insulation in all directions. This allows optimized thermal management without compromising electrical safety.

Inventive Principle:

Principle #3Local quality

2Temperature

If thermally conductive materials are used to manage heat buildup, then thermal management is improved, but parasitic electrical or magnetic behaviors increase

Engineering Contradiction:

Improveheat dissipationVSAvoidparasitic electrical behaviors

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The composite material combines electrically insulating polymer matrix with thermally conductive particles. This composition enables heat dissipation through the thermally conductive particles while the polymer matrix prevents parasitic electrical currents and magnetic behaviors by maintaining electrical insulation throughout the thermal management structure.

Inventive Principle:

Principle #40Composite materials

3Temperature

If additive particles are aligned using electromagnetic field, then thermal conductivity in specific direction is enhanced, but manufacturing complexity increases

Engineering Contradiction:

Improvedirectional thermal conductivityVSAvoidmanufacturing process complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent applies the electromagnetic field during the manufacturing process to align the thermally conductive particles within the polymer matrix before the composite fully sets. This preliminary alignment action creates the desired anisotropic thermal conductivity structure during fabrication, avoiding the need for complex post-processing steps to achieve directional thermal management.

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 composite material effectively manages thermal energy dissipation with reduced electrical conductivity, minimizing the risk of electrical shorts and parasitic behaviors, thus enhancing the operational reliability of electrical devices.

Implementation Method 1

The additive particles may be oriented into the aligned configuration using an electromagnetic field.

Methodology Applied

Scientific EffectElectromagnetic field: Electromagnetic Induction

Implementation Method 2

Thermally conductive materials may be used as thermal conductors to transport the thermal energy from the components where it is generated to a point of safe dissipation.

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11677282B2Composite material for thermal management in an electric motor

Publication Date: 2023.06.13 ACCELERATED SYST

AI summary

An electric motor including a stator having a stator slot, and a composite material within the stator slot. The composite material includes a matrix material, and additive particles having thermal conductivity and anisotropic electric properties. The additive particles are oriented in an aligned configuration and set to provide the composite material with thermal conductivity and reduced electrical conductivity in at least one direction based on the aligned configuration.