Two-Segment Electric Machine Housing Jacket for Cooling

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Solution Overview

Problem

The production of complex cooling channel structures in stator housings for electrical machines is costly and time-consuming, requiring advanced casting processes and posing challenges in design and contamination protection.

Innovation Solution

The stator housing is divided into two segments: a simple geometric segment for cost-effective production and a complex segment for advanced cooling channel creation, with connecting ducts forming a continuous cooling channel, allowing for reduced manufacturing effort and overall costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If complex cooling channel structures are produced by casting using contoured casting tools, then effective heat dissipation is achieved, but production costs increase and manufacturing complexity increases

Engineering Contradiction:
Improveheat dissipation effectivenessVSAvoidproduction cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The housing jacket is divided into two segments: a first segment with simple geometric cooling channels produced by conventional casting, and a second segment with complex cooling channels produced by advanced casting techniques. This segmentation allows each segment to be optimized for its specific manufacturing requirements while maintaining overall cooling effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The two housing jacket segments are joined together to form a complete housing with continuous cooling channels. The simple first segment and complex second segment are combined through precision joining techniques, merging the advantages of both manufacturing approaches while ensuring thermal continuity of the cooling system.

Inventive Principle:
Principle #5Merging (Combining)

2Temperature

If complex cooling channel structures are produced by casting using contoured casting tools, then effective heat dissipation is achieved, but manufacturing process complexity and design demands increase

Engineering Contradiction:
Improveheat dissipation effectivenessVSAvoidcasting process design complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The cooling channel system is segmented into simple and complex regions, with each region assigned to a specific housing jacket segment. This allows the complex casting process to be localized to only the necessary area rather than requiring the entire housing to be produced with advanced techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different manufacturing qualities are applied to different regions of the housing jacket. The first segment uses conventional casting suitable for simple channels, while the second segment employs advanced casting techniques specifically where complex cooling patterns are required for optimal heat dissipation.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the housing is divided into simple and complex geometric areas, then production costs are reduced, but the number of components and assembly steps increases

Engineering Contradiction:
Improveproduction costVSAvoidnumber of components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The two housing jacket segments are joined through precision machining and bonding processes that create a near-integral structure. The joining interface is designed to minimize assembly complexity while maintaining the cost advantages of segmented production, effectively merging the segments into a unified housing component.

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 approach simplifies the production of the housing jacket, reduces costs, and maintains effective heat dissipation while ensuring mechanical stability and reliability of the cooling channel structure.

Implementation Method 1

these cooling fins or cooling channels can be used to conduct a cooling liquid

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The frictional connection is usually realized via a press fit between the stator core and the stator housing

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

during assembly, the stator housing is heated so that it expands and the stator pack is cooled so that it contracts

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3338345B1Electric machine having a housing jacket consisting of two jacket segments
Publication Date: 2019.06.12 ROBERT BOSCH GMBH
  • EP3338345B1 patent drawingFigure 1~2
  • EP3338345B1 patent drawingFigure 3~4
  • EP3338345B1 patent drawingFigure 5~6

AI summary

The invention relates to a hollow cylindrical housing jacket (10) of an electric machine, which has a first jacket segment (10) having inner cooling channels (18), which are separated from each other and which extend from one circumferential end face (14) to the other circumferential end face (14) of the first jacket segment (12). In a second jacket segment (20), connecting channels (24) extend internally, which connecting channels cause a cooling-channel deflection in such a way that every pair of cooling channels (18) adjacent in the first jacket segment is connected by a cooling channel (24) in such a way that a continuous cooling channel of the housing jacket (10) is formed.