Electric Machine Cooling via Stator Core Channels

Solution Overview

Problem

Existing cooling assemblies for electric machines are inefficient in managing heat, leading to reduced power density and increased size and weight due to the need for cooling jackets and high shrink fit pressures, which complicates fluid cooling performance.

Innovation Solution

The cooling assemblies incorporate a stator and rotor core design with laminations and electrically insulated bars that form channels around the core, allowing for enhanced heat transfer without a cooling jacket, thereby increasing power density and reducing size and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling jackets and high shrink fit pressures are used for cooling electric machines, then cooling performance is improved, but device complexity and weight increase

Engineering Contradiction:

Improvecooling performanceVSAvoiddevice complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent removes the cooling jacket from the system entirely, extracting the harmful element that caused complexity and weight issues. Instead of adding a separate cooling jacket component, the invention integrates cooling functionality directly into the stator core structure through channels formed between laminations, thereby eliminating the need for external cooling jackets while maintaining effective heat dissipation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the structural support function with the cooling function by forming channels between stator core laminations that serve dual purposes: providing structural integrity and enabling fluid flow for heat dissipation. The bars embedded in the stator core also serve both as structural elements and as heat transfer pathways, combining multiple functions into unified components

Inventive Principle:

Principle #5Merging (Combining)

2Temperature

If cooling jackets and high shrink fit pressures are used for cooling electric machines, then cooling performance is improved, but size and weight increase

Engineering Contradiction:

Improvecooling performanceVSAvoidweight

Core Design Contradiction:

TemperatureVSWeight of stationary object

Solution Approach 1:

The patent removes the cooling jacket from the system entirely, extracting the harmful element that caused complexity and weight issues. Instead of adding a separate cooling jacket component, the invention integrates cooling functionality directly into the stator core structure through channels formed between laminations, thereby eliminating the need for external cooling jackets while maintaining effective heat dissipation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent utilizes the lamination structure itself as a porous-like framework, where channels are formed between adjacent laminations to allow fluid flow. This approach leverages the existing layered structure to create cooling passages without adding separate heavy components, achieving effective cooling while minimizing weight increase

Inventive Principle:

Principle #31Porous materials

3Temperature

If cooling jackets and high shrink fit pressures are used for cooling electric machines, then cooling performance is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvecooling performanceVSAvoidmanufacturing complexity

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent incorporates cooling channels directly into the stator core lamination assembly during the core manufacturing process, before final assembly. The channels are formed between laminations as they are stacked and secured with bars, integrating the cooling structure into the core fabrication workflow itself. This preliminary integration eliminates the need for separate cooling jacket installation steps and reduces overall manufacturing complexity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent merges the structural support function with the cooling function by forming channels between stator core laminations that serve dual purposes: providing structural integrity and enabling fluid flow for heat dissipation. The bars embedded in the stator core also serve both as structural elements and as heat transfer pathways, combining multiple functions into unified components

Inventive Principle:

Principle #5Merging (Combining)

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 design effectively cools electric machines by increasing power density, reducing size and weight, and eliminating the need for cooling jackets, while optimizing fluid cooling performance and minimizing overheating.

Implementation Method 1

at least one bar disposed in the at least one opening, where the at least one bar is electrically insulated from the at least some laminations

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9819248B2Assemblies and methods for cooling electric machines

Publication Date: 2017.11.14 TECO WESTINGHOUSE MOTOR CO

AI summary

Cooling assemblies and methods, including, for example, at least one bar (e.g., electrically insulated and/or thermally conductive bar(s)), members (e.g., i-beams, rectangular members, and the like), stator laminations, rotor laminations, and/or combinations thereof, such as those configured to cool electric machines (e.g., electric motors and generators).