Insulated Bus Bar Cover Assembly for Electrical Machine Housings

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Solution Overview

Problem

Conventional electrical machines, particularly electric motors for vehicle power steering, have a high number of parts and complex assembly processes due to bus bars and their fastening means, leading to increased production costs and quality assurance issues.

Innovation Solution

Embed bus bars in an electrically insulating lid material of a cover, ensuring electrical insulation and integration as a structural unit, eliminating the need for separate fastening means and reducing the number of parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bus bars and fastening means are used separately, then electrical connection is achieved, but the number of parts and assembly complexity increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidnumber of parts and assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bus bars are embedded directly into the lid material of the cover, merging the electrical connection element with the housing component. This integration eliminates separate fastening means and reduces the total number of parts, while maintaining reliable electrical connection between the stator windings and external current source

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lid material is designed as an electrically insulating composite material that can embed and electrically isolate the conductive bus bars. This composite structure provides both mechanical housing function and electrical insulation, eliminating the need for separate insulators and fastening components

Inventive Principle:
Principle #40Composite materials

2Reliability

If multiple separate components are used, then functional requirements are met, but production costs increase

Engineering Contradiction:
Improvequality assuranceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By integrating the bus bars into the lid material during the molding process, the patent reduces the number of separate components that need to be manufactured, stored, and assembled. This simplification directly reduces production costs while maintaining quality assurance through fewer assembly steps and less human intervention

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If complex mounting processes are used, then proper assembly is achieved, but time consumption and error risk increase

Engineering Contradiction:
Improveassembly precisionVSAvoidmounting speed and error rate
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The bus bars are pre-positioned and embedded into the lid material during the cover manufacturing process, before the actual assembly of the electrical machine. This preliminary action ensures correct positioning and electrical connection without requiring complex mounting operations during final assembly, thereby increasing productivity and reducing assembly errors

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3863157B1Cover for closing a housing of an electrical machine
Publication Date: 2025.08.27 MAHLE INT GMBH
  • EP3863157B1 patent drawingFigure 1~2
  • EP3863157B1 patent drawingFigure 3~4f

AI summary

The invention relates to a cover (1) for closing a housing (16) of an electrical machine (20), wherein the cover (1) comprises a lid body (2) of an electrically insulating lid material (3) as well as at least two bus bars (4), wherein each of the bus bars (4) has a first electrical connection (5) and two second electrical connections (6). The first and the second electrical connections (5, 6) of a respective one of the bus bars (4) are thereby electrically connected to one another by means of this bus bar (4). The bus bars (4) are thereby embedded in the electrically insulating lid material (3) in such a way that the bus bars (4) are electrically insulated from one another by means of the electrically insulating lid material (3).