Stator Cooling via Embedded Plastic Compound and Integrated Chambers

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Solution Overview

Problem

Conventional electric machines face challenges in efficiently transferring heat from stator windings to coolants due to complex construction requirements, leading to increased production costs and potential overheating issues.

Innovation Solution

Embedding stator windings in a plastics compound with integrated coolant distributor and collector chambers, utilizing thermally conductive plastics to enhance heat transfer while maintaining electrical insulation, thereby simplifying the cooling process and reducing production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional cooling channels are used to transfer heat from stator windings to coolant, then heat dissipation is achieved, but construction complexity and production costs increase significantly

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidconstruction complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling channel structure with the stator body by integrating the coolant distributor chamber and cooling channels directly into the stator's plastic compound. This eliminates the need for separate cooling components and reduces construction complexity while maintaining effective heat dissipation from the stator windings.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a plastic compound with enhanced thermal conductivity (through additives or fillers) to create the stator body. This composite material enables efficient heat transfer from the windings to the coolant while maintaining the structural integrity and electrical insulation properties of the stator, thereby achieving good heat transfer without complex construction.

Inventive Principle:

Principle #40Composite materials

2Temperature

If conventional cooling channels are used to transfer heat from stator windings to coolant, then heat dissipation is achieved, but production costs increase due to additional construction outlay

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidproduction cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The cooling channels and distributor chambers are merged into the stator body as an integrated structure. This allows the entire stator to be manufactured in a single injection molding process, eliminating the need for separate manufacturing and assembly steps for cooling components, thereby significantly reducing production costs.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent modifies the physical parameters of the plastic material by incorporating thermal conductive additives or fillers. This changes the thermal conductivity parameter of the plastic compound, enabling efficient heat transfer without requiring complex cooling channel geometries or additional cooling components, thus simplifying manufacturing and reducing costs.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If plastic is used as heat-transferring medium, then electrical insulation is maintained, but thermal conductivity must be enhanced

Engineering Contradiction:

Improveelectrical insulationVSAvoidthermal conductivity

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent uses composite plastic materials that combine the electrical insulation properties of plastic with enhanced thermal conductivity. By incorporating thermal conductive fillers or additives into the plastic matrix, the material achieves improved heat transfer capability while maintaining its inherent electrical insulation properties, thus resolving the contradiction between these two requirements.

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 approach enables effective heat dissipation from stator windings, preventing overheating and reducing production costs by using thermally conductive plastics to efficiently transfer heat to coolants, ensuring reliable operation of electric machines.

Implementation Method 1

the plastic is utilized as a heat-transferring medium for the transfer of heat from the stator windings to the coolant

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the coolant absorbs, by thermal interaction, the waste heat generated by the stator windings

Methodology Applied

Scientific EffectHeat transfer: Convection

Data Source

PatentUS11476730B2Electrical machine with stator with coolant distributor chamber and coolant collector chamber

Publication Date: 2022.10.18 MAHLE INT GMBH

AI summary

An electric machine, for example for a motor vehicle, is disclosed. The electric machine includes a rotor rotatable about an axis of rotation that defines an axial direction of the electric machine, and a stator including stator windings. A coolant distributor chamber and a coolant collector chamber are provided, and arranged with an axial spacing to one another. The coolant distributor chamber fluidically communicates with the coolant collector chamber for cooling the stator windings via at least one cooling channel that can be flowed through by a coolant. At least one of the stator windings is embedded into a plastics compound composed of an electrically insulating plastic for thermal coupling.