Brushless Motor Cooling Layout for Redundant Coil Groups

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Solution Overview

Problem

Brushless electric motors lack reliability and safety, especially when used in applications like electric cars, due to insufficient redundancy and efficient cooling systems.

Innovation Solution

A brushless electric motor system with a stator having at least three groups of six teeth with adjacent coils, each group divided into pairs, and a single power stage for each pair, along with a unified cooling system that uses heat resistance inserts to manage thermal conductivity between coils and power stages, enhancing redundancy and cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional brushless electric motor systems are used, then the structure is simpler, but the reliability and safety are insufficient

Engineering Contradiction:
ImprovereliabilityVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The stator is divided into three groups of six teeth, with each group containing three pairs of coils. This segmentation creates modular units that can operate independently, so if one group fails, the other groups can continue to provide power, thereby improving reliability without requiring a completely different motor architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The motor is designed with redundant coil groups that serve as backup capacity. When coils are arranged in pairs within groups, and groups are positioned adjacently, the system prepares in advance for potential failures by having alternative pathways for power generation, ensuring continued operation even when some components fail

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Temperature

If separate cooling systems are used for coils and power stages, then cooling effectiveness is improved, but weight and complexity increase

Engineering Contradiction:
Improvecooling effectivenessVSAvoidcooling system
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The cooling system merges the cooling of coils and power stages into a single integrated system. By using heat resistance inserts that manage thermal conductivity between coils and power stages, one cooling circuit can effectively cool both components, reducing the number of separate cooling systems needed while maintaining adequate temperature control

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Heat resistance inserts act as intermediary elements between the coils and power stages. These inserts mediate thermal transfer, allowing a single cooling system to manage heat from both sources by controlling the thermal conductivity between components, thereby simplifying the cooling architecture while maintaining effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple power stages are used for each coil pair, then control precision is improved, but redundancy decreases

Engineering Contradiction:
ImproveredundancyVSAvoidcontrol precision
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

Each power stage is designed to universally control multiple coil pairs across different groups. The power electronic means can switch between and control any of the three groups, making each power stage multi-functional. This approach maintains redundancy by having fewer dedicated power stages while preserving control capability through flexible switching between coil groups

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 system provides increased reliability and safety by ensuring continued operation even if one group fails, with reduced power output, and improves efficiency by using a single cooling system for both coils and power stages, reducing weight and complexity.

Implementation Method 1

a stator comprising a plurality of electrically excitable coils for generating an induction field for interaction with said plurality of permanent magnets to cause said rotor to rotate with respect to said stator

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a base cooling plate connected to a first flat surface of said hollow main cool body and to said plurality of power stages for transferring heat between said plurality of power stages and said base cool plate

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

heat resistance inserts connected to said base cooling plate and said plurality of electrically excitable coils for transferring heat between said plurality of coils and said base cooling plate

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3476025B1A brushless electric motor system comprising a rotor, a stator and power electronic means.
Publication Date: 2024.11.20 SALUQI HLDG BV
  • EP3476025B1 patent drawingFigure 1
  • EP3476025B1 patent drawingFigure 2
  • EP3476025B1 patent drawingFigure 3

AI summary

A brushless electric motorsystem having integrated power stages, said electric motor system comprising a rotor, a stator, a plurality of power stages, and a cooling system comprising a substantially flat hollow main cool body arranged to support the flowing of a cooling medium inside said hollow main cool body for cooling said main cool body, a base cooling plate connected to a first flat surface of said hollow main cool body and to said plurality of power stages for transferring heat between said plurality of power stages and said base cool plate, heat resistance inserts connected to said base cooling plate and said plurality of electrically excitable coils for transferring heat between said plurality of coils and said base cooling plate wherein said heat resistance inserts provide for a thermal conductivity, thereby creating a thermal buffer such that said electrically excitable coils are cooled less compared to said power stages, by said cooling system.