Electric Drive Unit Axial Connector Segmentation

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Solution Overview

Problem

Existing drive units for motor vehicles with electric machines face challenges in optimizing the radial space occupied by the rotor and stator, and the connection device requires significant axial and radial space, which limits efficiency and requires complex sealing measures to prevent moisture ingress.

Innovation Solution

The drive unit separates the electrical connection between the stator and the connection device into two sections, using axial connectors and wall contacts that form a plug-in connection, allowing the connection device to be positioned independently of the electric machine's housing, thus eliminating the need for radial space within the housing and enabling a more efficient use of available space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the connection device is fixed to the housing element surrounding the stator, then the electrical connection is secure, but radial space within the housing is consumed and complex sealing measures are required

Engineering Contradiction:

Improveelectrical connection securityVSAvoidradial space in housing

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The electrical connection is divided into two separate sections: stator contacts integrated with the stator and wall contacts integrated with the housing wall. This segmentation allows each component to be optimized independently and eliminates the need for a separate connection device that would consume radial space.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stator contacts are merged with the stator structure and the wall contacts are merged with the housing wall structure. This integration eliminates separate connection components and reduces the radial space required within the housing.

Inventive Principle:

Principle #5Merging (Combining)

2Area of stationary object

If the connection device is arranged radially outside the first chamber, then radial space is reduced, but excessive axial lengthening of the housing is required

Engineering Contradiction:

Improveradial spaceVSAvoidaxial length of housing

Core Design Contradiction:

Area of stationary objectVSLength of moving object

Solution Approach 1:

The connection is repositioned from a radial arrangement (which would require axial lengthening) to an axial arrangement where stator contacts extend axially from the stator and connect with wall contacts in the housing wall. This dimensional change allows connection without increasing axial housing length.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If the connection device requires sealing measures to prevent moisture ingress, then electrical protection is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improveprotection against moistureVSAvoidsealing measures

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The connection device is extracted from the housing structure and replaced with integrated stator contacts and wall contacts. This elimination of the separate connection device removes the need for complex sealing measures around connection components.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The housing wall serves multiple functions: it provides structural support, contains the magnetic circuit, and integrates the wall contacts for electrical connection. This multi-functionality reduces the need for separate sealed connection chambers.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP2367266B1Drive unit for a motor vehicle with an electric machine

Publication Date: 2019.06.05 ZF FRIEDRICHSHAFEN AG

Figure 1

AI summary

A drive unit for a motor vehicle with an electric machine is described, comprising a rotor rotatably mounted about an axis A, which can be coupled to or is coupled to a drive shaft acting on the vehicle wheels, and a stator having an electrical winding whose winding ends can be connected to a power source by means of a connection device arranged on or through a housing opening of the drive unit, and further comprising a housing element radially surrounding the rotor and the stator. For space-optimized arrangement of the connection device, it is provided that the winding ends are connected to first contact elements, which are fixed in position on the stator and are designed as axial connectors with respect to the electric machine, and which represent the stator contacts.Furthermore, these first contact elements can be connected or are connected to second contact elements, which are designed corresponding to the first contact elements and are arranged on a wall area of the drive unit and represent the wall contacts, wherein the wall contacts are electrically connected to or form the connection device.