Electric Axle Housing with Flat Underbody for Modular Pre-Assembly

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Solution Overview

Problem

Existing two-track vehicle axle designs for electric vehicles complicate manufacturing and assembly, particularly in integrating and testing electric drive components before vehicle body assembly, and require complex high-current wiring installations.

Innovation Solution

The axle design features a housing or base body with articulated wheel-guiding links, integrating an electric motor, transfer case, differential, and a unit for providing electrical energy, including accumulators or fuel cells, which can be pre-assembled and tested independently before vehicle body integration, with electrical wiring pre-assembled for efficiency and protection from environmental influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If electric drive components are integrated into the axle carrier before vehicle body assembly, then manufacturing efficiency and testing capability are improved, but device complexity and assembly complexity increase

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidassembly complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The axle system is divided into modular components: axle carrier, wheel-guiding links, electric motor, transfer case, differential, and housing. These modules can be independently manufactured and assembled, allowing pre-assembly of electric drive components without significantly increasing overall complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The axle carrier serves multiple functions: it carries the electric motor, transfer case, differential, and wheel-guiding links, while also providing structural support and mounting points for the vehicle body. This multi-functionality reduces the need for separate components.

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

2Device complexity

If electrical wiring is pre-assembled on the axle, then wiring installation complexity is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvewiring installation complexityVSAvoidwiring assembly precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

Electrical wiring between the unit for providing electrical energy and the electric motor(s) is pre-assembled on the axle during the pre-assembly phase. This preliminary action simplifies the final vehicle assembly process, though it requires precise manufacturing procedures.

Inventive Principle:
Principle #10Preliminary action

3Object-generated harmful factors

If the housing is made flat on the underbody side, then aerodynamic performance is improved, but structural strength may be reduced

Engineering Contradiction:
Improvedrag coefficientVSAvoidhousing structural strength
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The housing has different geometries for different functions: the underbody side is made flat to reduce drag coefficient and improve aerodynamics, while other portions of the housing maintain sufficient structural strength to protect internal components and provide mounting points.

Inventive Principle:
Principle #3Local quality

4Productivity

If multiple components are integrated into the axle carrier, then manufacturing efficiency is improved, but ease of repair and maintenance deteriorates

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidcomponent accessibility
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

The axle system is segmented into independently replaceable modules (electric motor, transfer case, differential, wheel-guiding links). This segmentation allows efficient manufacturing through pre-assembly while enabling easy repair by replacing individual modules rather than the entire axle carrier.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2640588B1Electrically driven axle of a two-track vehicle
Publication Date: 2017.12.20 BAYERISCHE MOTOREN WERKE AG
  • EP2640588B1 patent drawingFigure 1~2
  • EP2640588B1 patent drawingFigure 3~4

AI summary

The invention relates to an electrically driven axle of a two-track vehicle having drive shafts which are assigned to the wheels and an axle carrier with a plurality of wheel-guiding steering arms which are attached thereto, wherein at least one electric motor is attached to the axle carrier, and furthermore a housing containing elements for making available electrical energy for the electric motor is attached to the axle carrier or forms a component of the axle carrier in the form of a base body. At least one of the wheel-guiding steering arms is connected to said base body or housing, and arms extend from the base body of the axle carrier, on the end regions of which arms the vehicle body is supported via rubber bearings. The underfloor of the base body or housing facing the carriageway is preferably essentially planar.