Rotor Cooling via Rib-Shaped Heat Exchanger Structures

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Solution Overview

Problem

Existing rotor designs with permanent magnets face irreversible demagnetization due to excessive temperatures, leading to manufacturing complexity and weight increases from additional cooling units like fans, which are not effectively addressed in current solutions.

Innovation Solution

A rotor design featuring an annular structure with permanent magnets on the outer radius and a conical hub structure on the inner radius, connected by rib-shaped or blade-shaped structures that function as a mechanical connection and heat exchanger, utilizing the existing mechanical rotating support structure to provide effective cooling without separate cooling units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If additional fans (axial or radial) are mounted concentrically on the rotor shaft for cooling, then the cooling effect for permanent magnets is improved, but the device complexity and weight increase

Engineering Contradiction:
Improvecooling effectVSAvoidconstruction complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines the mechanical support structure (ribs or blades) with the cooling function by designing these structures to simultaneously provide mechanical connection and act as heat exchangers, eliminating the need for separate fan components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rib-shaped or blade-shaped structures serve multiple functions: they provide mechanical connection between the annular and hub structures, act as heat exchangers for cooling permanent magnets, and function as structural support elements, thereby reducing overall device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Temperature

If additional fans are mounted on the rotor shaft for cooling, then the cooling effect is improved, but the weight of the rotor increases

Engineering Contradiction:
Improvecooling effectVSAvoidrotor weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The cooling function is merged into the existing mechanical support structures, eliminating the need for additional fan components that would increase rotor weight

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rib-shaped or blade-shaped structures perform multiple functions including mechanical support and heat exchange, thereby avoiding the weight penalty of adding dedicated cooling components

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If additional separate cooling units are used, then the cooling reliability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvecooling reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cooling function is integrated into the existing mechanical structures, reducing the number of separate components and simplifying the manufacturing process while maintaining reliable cooling

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-functional rib-shaped or blade-shaped structures reduce manufacturing complexity by eliminating the need to manufacture and assemble separate cooling units, while still providing reliable cooling through their heat exchange capability

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

This design simplifies manufacturing, reduces weight, and achieves reliable cooling for permanent magnets, enhancing ventilation and production aspects while maintaining a high cooling effect, thereby preventing demagnetization and increasing power density in electrical machines.

Implementation Method 1

an existing mechanical rotating support structure is used at the same time as a rotating heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

Targeted air cooling of the rotor counteracts impermissible heating of the rotor magnets due to eddy current losses and heat input

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3403317B1Rotor and electrical machine
Publication Date: 2020.04.08 ROLLS ROYCE DEUT LTD & CO KG
  • EP3403317B1 patent drawingFigure 1~2
  • EP3403317B1 patent drawingFigure 3~4

AI summary

The invention relates to a weight-optimized, meridian-accelerated rotor (1) having permanent magnets (7) that are securely supplied with a required cooling during use. The invention further relates to a corresponding electrical machine, in which the problem of demagnetization of existing permanent magnets (7) due to rotor temperatures that are too high is avoided. The rotor (1) or the rotor (1) of an affected electrical machine has an annular structure (6) on the outside radius (5) for receiving the permanent magnets (7), furthermore has a conical hub structure (10) on an inside radius (9) and finally has a plurality of at least rib-shaped or blade-shaped structures (12) between the annular structure (6) and the conical hub structure (10) in order to form a mechanical connection of the annular structure (6) and conical hub structure (10).