Integrated Stator Core Cooling Channels for Simpler Motor Thermal Design

Solution Overview

Problem

Existing electrical machine stator cooling systems are technically complex and costly due to the use of additional cooling tubes, which increases production costs and complexity.

Innovation Solution

The integration of cooling channels directly within the stator laminated core, defined by the stator laminations, eliminates the need for additional cooling tubes, allowing for a simpler and lighter construction by using the stator laminations to form the cooling channels, and utilizing oil as a combined cooling and lubricating medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling tubes are provided in the stator to cool the stator, then the stator cooling effectiveness is improved, but the device complexity and production cost increase

Engineering Contradiction:

Improvestator cooling effectivenessVSAvoidcooling system complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The cooling channels are merged directly into the stator laminated core structure, eliminating the need for separate cooling tubes. The stator laminations themselves form the cooling channels, combining the structural and cooling functions into a single integrated component, thereby reducing device complexity while maintaining cooling effectiveness

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The stator laminations serve dual functions: they provide the structural framework of the stator and simultaneously form the cooling channels. This multi-functionality eliminates the need for dedicated cooling tubes, reducing both complexity and production cost while maintaining effective stator cooling

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Temperature

If cooling tubes are provided in the stator to cool the stator, then the stator cooling effectiveness is improved, but the production cost increases

Engineering Contradiction:

Improvestator cooling effectivenessVSAvoidproduction cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The cooling channels are merged directly into the stator laminated core structure, eliminating the need for separate cooling tubes. The stator laminations themselves form the cooling channels, combining the structural and cooling functions into a single integrated component, thereby reducing device complexity while maintaining cooling effectiveness

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The stator laminations serve dual functions: they provide the structural framework of the stator and simultaneously form the cooling channels. This multi-functionality eliminates the need for dedicated cooling tubes, reducing both complexity and production cost while maintaining effective stator cooling

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Temperature

If additional cooling tubes are provided to cool the stator, then the cooling effectiveness is improved, but the electrical machine weight increases

Engineering Contradiction:

Improvestator cooling effectivenessVSAvoidelectrical machine weight

Core Design Contradiction:

TemperatureVSWeight of moving object

Solution Approach 1:

The cooling channels are merged directly into the stator laminated core structure, eliminating the need for separate cooling tubes. The stator laminations themselves form the cooling channels, combining the structural and cooling functions into a single integrated component, thereby reducing device complexity while maintaining cooling effectiveness

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The stator laminations serve dual functions: they provide the structural framework of the stator and simultaneously form the cooling channels. This multi-functionality eliminates the need for dedicated cooling tubes, reducing both complexity and production cost while maintaining effective stator cooling

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 approach reduces technical complexity and production costs while effectively cooling the stator, allowing for a more efficient and lightweight electrical machine design, with oil serving as both a heat transfer medium and lubricant, enhancing cooling efficiency.

Implementation Method 1

cooling channels arranged fully in the stator laminated core and edged by the latter

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

Waste heat from the electrical machine and also of the transmission is transported, for example, to a heat exchanger with the aid of the lubricating oil

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS11936242B2Electrical machine, gear motor comprising an electrical machine, and vehicle comprising an electrical machine

Publication Date: 2024.03.19 VALEO EAUTOMOTIVE GERMANY GMBH

AI summary

Described is an electrical machine (1) which comprises two end shields (6, 7), a stator (5) which is arranged between the two end shields (6, 7) and has a stator laminated core (11, 11a) and stator windings (12) arranged therein, and a rotor (3) which is arranged in the stator (5) and has a rotor shaft (2) mounted rotatably in the two end shields (6, 7). The electrical machine (1) furthermore has cooling channels (13) arranged fully in the stator laminated core (11, 11a) and edged by the latter. Furthermore described are a gear motor (30) comprising such an electrical machine (1), as well as a vehicle (20) comprising such an electrical machine (1).