Overmolded Busbar Connection Element for Flexible Electric Machines

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Solution Overview

Problem

Existing connection devices for multi-phase electrical machines are not easily adaptable to various electrical machine configurations and power sources, requiring complex and costly manufacturing processes to ensure reliable connections.

Innovation Solution

A connection device featuring uncoated electrically conductive current rail elements fixed by an electrically insulating injection molding element, allowing for easy adjustment and adaptation to different electrical machine configurations, with ends coupled to the stator and inverter, and a sealing element for secure housing integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional connection devices are used for multi-phase electrical machines, then reliable electrical connections are achieved, but the manufacturing process becomes complex and costly, and adaptability to different configurations is reduced

Engineering Contradiction:
Improveadaptability to different electrical machine configurationsVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connection device is segmented into separate busbar elements that can be individually positioned and configured. Each busbar element can be independently arranged to match different phase configurations, allowing the same basic structure to adapt to various electrical machine setups without requiring complete redesign of the connection system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection device is designed as a universal structure that can serve multiple configurations. The standardized busbar elements and modular design allow the same connection device to be used across different electrical machine types and power source configurations, eliminating the need for specialized manufacturing processes for each variant.

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

2Reliability

If individualized connection elements are created for each electrical machine variant, then optimal connections are achieved, but manufacturing costs and process complexity increase

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing cost and ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The busbar elements are pre-configured with standardized connection points and geometries during manufacturing. This preliminary preparation allows for rapid assembly and ensures consistent, reliable connections without requiring complex custom manufacturing processes for each electrical machine variant. The standardized design enables mass production while maintaining connection reliability.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If uncoated electrically conductive materials are used for busbar elements, then manufacturing simplicity and cost-effectiveness are improved, but electrical conductivity and corrosion resistance may be compromised

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidelectrical conductivity reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection device utilizes composite material construction where uncoated electrically conductive busbar elements are combined with electrically insulating injection-molded material. This composite structure provides both the electrical conductivity needed for power transmission and the insulation required for safety, while maintaining manufacturing simplicity by eliminating the need for separate coating processes.

Inventive Principle:
Principle #40Composite materials

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

Enables a cost-effective, flexible, and reliable connection solution that can be easily manufactured and adapted to various electrical machine configurations, ensuring efficient energy transfer and sealing, thus addressing the need for individualized connections.

Implementation Method 1

The plurality of busbar elements are each enclosed at predetermined positions by an electrically insulating injection-molded element. This fixes the plurality of busbar elements.

Methodology Applied
Scientific EffectInjection molding:

Implementation Method 2

The method further comprises a step of overmolding the plurality of busbar elements with an electrically insulating material. In this way, an electrically insulating injection-molded element is formed around the busbar elements.

Methodology Applied
Scientific EffectOvermolding:

Data Source

PatentEP4503397A1Connection device for an electric machine, electric machine and method for producing a connection device for an electric machine
Publication Date: 2025.02.05 ROBERT BOSCH GMBH
  • EP4503397A1 patent drawingFigure 1~2
  • EP4503397A1 patent drawingFigure 3~4
  • EP4503397A1 patent drawing

AI summary

The invention relates to a connection element for a multi-phase electric machine. The connection element is designed to be so simple that it can be produced using a basic injection molding process in which several busbar elements are overmolded. By varying the busbar elements, a high degree of flexibility for the electric machine's connection element can be achieved within a consistent injection molding process.