Plastic Liquid-Cooled Drive and Inductor Assembly for Corrosion-Free Cooling

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Solution Overview

Problem

Existing cooling systems for variable speed drives and inductors are bulky, heavy, and prone to wirebond failures due to thermal and power cycling, with aluminum electrolytic capacitors and copper heatsinks causing corrosion and maintenance issues, and liquid-cooled inductors requiring de-ionized water to prevent copper plating.

Innovation Solution

A power assembly with a plastic cooler that directs coolant fluid onto electronic components, using a lightweight and cost-effective plastic material with low thermal expansion, replacing traditional electrolytic capacitors with film capacitors, and employing a five-legged core liquid-cooled inductor with thermally conductive materials for efficient heat transfer and reduced size and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If aluminum electrolytic capacitors and copper heatsinks are used in traditional power assemblies, then effective cooling and electrical performance are achieved, but the assembly becomes bulky, heavy, and prone to corrosion and wirebond failures

Engineering Contradiction:
Improvewirebond failure resistanceVSAvoidpower assembly weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the material parameters by replacing aluminum electrolytic capacitors with film capacitors and copper heatsinks with plastic coolers. This material substitution reduces weight while maintaining cooling effectiveness and improving reliability by eliminating corrosion-prone materials and reducing thermal expansion mismatches that cause wirebond failures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite material structures, particularly the plastic cooler that integrates cooling channels with mounting features, and combines film capacitors with plastic housing. This composite approach achieves both weight reduction and improved mechanical properties while maintaining thermal management capabilities.

Inventive Principle:
Principle #40Composite materials

2Temperature

If copper heatsinks are used for cooling, then effective heat dissipation is achieved, but corrosion occurs when in contact with cooling fluid

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidcorrosion
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces expensive, corrosion-prone copper heatsinks with more affordable plastic coolers that are resistant to corrosion. The plastic material, while having different thermal properties, is designed with integrated cooling channels that maintain effective heat dissipation without the corrosion issues of copper.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The plastic cooler design incorporates localized thermal management features, including optimized cooling channel geometries and strategic placement of heat dissipation structures in high-heat areas, compensating for the lower thermal conductivity of plastic compared to copper.

Inventive Principle:
Principle #3Local quality

3Temperature

If liquid cooled inductors with copper tubing are used, then effective cooling is achieved, but de-ionized water is required to prevent copper plating

Engineering Contradiction:
Improveinductor cooling efficiencyVSAvoidcooling system maintenance
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent replaces copper tubing inductors with plastic-cooled inductor designs that eliminate copper plating issues. The plastic cooler design allows for simpler cooling fluid requirements, reducing maintenance complexity while maintaining cooling effectiveness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Strength

If traditional power assembly designs with metallic frames and multiple components are used, then structural support is achieved, but the assembly becomes bulky and heavy

Engineering Contradiction:
Improvestructural supportVSAvoidpower assembly volume
Core Design Contradiction:
StrengthVSVolume of stationary object

Solution Approach 1:

The patent merges multiple functions into the plastic cooler component, which provides both structural support and thermal management. The plastic housing integrates mounting features, cooling channels, and structural support functions, eliminating the need for separate metallic frames and reducing overall assembly volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plastic cooler serves multiple functions simultaneously: it provides structural support for mounting components, acts as a heat sink with integrated cooling channels, and serves as a protective enclosure. This multi-functionality reduces the number of separate components needed, decreasing both volume and weight.

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

The solution reduces the size, weight, and cost of the power assembly while maintaining effective cooling, preventing corrosion, and minimizing wirebond failures through efficient heat transfer and using film capacitors for increased reliability.

Implementation Method 1

a plastic cooler that directs coolant fluid onto electronic components

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

employing a five-legged core liquid-cooled inductor with thermally conductive materials for efficient heat transfer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2127511B1Cooling system for variable speed drives and inductors
Publication Date: 2015.11.04 JOHNSON CONTROLS TECHNOLOGY CO
  • EP2127511B1 patent drawingFigure 1A~1B
  • EP2127511B1 patent drawingFigure 2A~2B
  • EP2127511B1 patent drawingFigure 3

AI summary

A plastic liquid cooled variable speed drive or inductor provided. The cooler provides lightweight, space conservative, corrosive free cooling to the components as well as provides a mounting area for modules. A cooler can be mounted to the core of an inductor to absorb heat generated by the core losses.