Electric Drive Power Electronics Layout Around the Drive Shaft

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Solution Overview

Problem

Existing integrated electric drive systems inefficiently utilize space and hinder heat dissipation due to the fixed layout of the power electronics module, which limits the dimensions and arrangement of electronic devices.

Innovation Solution

The power electronics module is arranged around the drive shaft of the transmission, forming a hollow structure with the electronic device inside, allowing for a compact design and improved heat dissipation through integrated cooling circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the power electronics module is arranged at one side of the transmission drive shaft, then the structure is simplified and space between transmission and wheel is utilized, but the amount of space at this side limits the dimensions of the power electronics module and affects heat dissipation

Engineering Contradiction:
Improvestructural simplicityVSAvoidheat dissipation capability
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent transitions from a two-dimensional side-by-side arrangement to a three-dimensional arrangement where the power electronics module is positioned around the drive shaft, utilizing the radial space in multiple directions. This dimensional change allows the module to extend circumferentially around the drive shaft rather than being constrained to a single side, effectively using available space in all radial directions for heat dissipation and module dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the power electronics module is arranged at one side of the transmission drive shaft, then the layout is compact, but space at the other side of the drive shaft is unused, resulting in space waste

Engineering Contradiction:
Improveassembly compactnessVSAvoidspace utilization
Core Design Contradiction:
Volume of moving objectVSArea of stationary object

Solution Approach 1:

The power electronics module is nested around the drive shaft, with the drive shaft passing through the hollow interior of the module. This nesting arrangement allows the module to occupy the annular space between the drive shaft and the outer housing, effectively utilizing the previously wasted space on the opposite side of the drive shaft while maintaining compact overall dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Area of stationary object

If the power electronics module is arranged around the drive shaft in a hollow structure, then space usage is maximized and heat dissipation is improved, but the structural complexity increases

Engineering Contradiction:
Improvespace utilizationVSAvoidstructural complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The drive shaft serves multiple functions: it transmits mechanical torque and simultaneously acts as a structural support around which the power electronics module is arranged. The hollow structure of the module serves dual purposes by providing mechanical support while also creating internal space for electronic components and facilitating heat dissipation pathways.

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

4Temperature

If the electronic device dimensions are increased for better heat dissipation, then heat dissipation capability is improved, but the available space at one side of the drive shaft is insufficient

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidavailable space
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The patent resolves the space limitation by transitioning from a linear one-side arrangement to a circumferential arrangement around the drive shaft. This allows the electronic device to expand in the radial and circumferential directions rather than being constrained to a single linear direction, effectively utilizing the annular space surrounding the drive shaft for increased heat dissipation surface area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration maximizes space usage, reduces installation space, and enhances heat dissipation capabilities, resulting in a more compact and efficient integrated electric drive system.

Implementation Method 1

at least one of the first housing, the second housing and the third housing is provided with a cooling circuit

Methodology Applied
Scientific EffectHeat dissipation: Convection

Data Source

PatentEP4034400B1Integrated electric drive system and electric vehicle
Publication Date: 2023.11.08 ROBERT BOSCH GMBH
  • EP4034400B1 patent drawingFigure 1
  • EP4034400B1 patent drawingFigure 2

AI summary

The present application provides an integrated electric drive system, comprising: an electric machine, comprising a first housing and an output shaft; a transmission, comprising a second housing and a drive shaft, the transmission receiving an input torque of the output shaft and outputting same via the drive shaft; a power electronics module, comprising a third housing and an electronic device, the electronic device being configured to provide electric power for the electric machine; wherein the power electronics module is configured to be arranged around the drive shaft. In addition, the present application also provides an electric vehicle comprising the integrated electric drive system described above. The integrated electric drive system of the present application has a more compact structure with a higher degree of integration, and better heat dissipation capability, facilitating spatial optimization and lightweight design of the electric vehicle.