Stator Connection Element Assembly for Automated Hairpin Winding

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Solution Overview

Problem

Existing methods for manufacturing stators for electric motors are costly, require significant development effort, and lack scalability and automation, particularly for efficient winding technologies like wave and hairpin windings.

Innovation Solution

A fully automated manufacturing process for stators using a connection element with busbars and a star busbar, overmolded with insulating material, where winding ends are bent over a bending comb and welded or soldered to contact points, followed by insulating material encapsulation to ensure electrical insulation and reduce positional tolerances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If traditional manual methods are used for manufacturing stators, then flexibility in handling complex wiring configurations is maintained, but manufacturing costs increase and automation capability is lost

Engineering Contradiction:

Improveautomation capabilityVSAvoidwiring configuration complexity

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The connection element is segmented into multiple busbars with individual contact points, allowing automated placement while maintaining flexibility for different wiring configurations. Each busbar can be independently positioned and connected to corresponding winding ends, enabling automated assembly processes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The connection element serves multiple functions: it provides electrical connection between windings and phases, offers mechanical support for winding ends, enables automated placement through standardized features, and accommodates various wiring configurations through its multi-busbar design with adjustable contact points.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple separate connection elements are used for each phase, then precise positioning and electrical insulation are improved, but the number of components and assembly steps increases

Engineering Contradiction:

Improvepositioning precisionVSAvoidassembly efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

Multiple busbars are merged into a single integrated connection element that provides electrical connections for all phases. This unified structure maintains precise positioning capability through its overall geometry and footprint, while reducing the number of separate components that need to be handled and assembled, thereby improving productivity.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If conventional connection methods are used without overmolding, then manufacturing simplicity is maintained, but electrical insulation reliability and positional stability deteriorate

Engineering Contradiction:

Improveelectrical insulation reliabilityVSAvoidmanufacturing simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The connection element combines conductive materials (busbars for electrical connection) with insulating material (overmold that encapsulates the busbars). This composite structure provides both reliable electrical insulation between phases and positional stability for the connection element, while the overmolding process integrates these functions in a single manufacturing step.

Inventive Principle:

Principle #40Composite materials

4Reliability

If larger clearance distances are maintained between conductors, then electrical insulation safety is improved, but installation space increases

Engineering Contradiction:

Improveelectrical insulation safetyVSAvoidinstallation space

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

A thin insulating overmold encapsulates the busbars and connection elements, providing the necessary electrical insulation in a minimal thickness. This thin film approach maintains adequate insulation distances for safety while occupying minimal space, allowing compact stator design without compromising electrical insulation reliability.

Inventive Principle:

Principle #30Flexible shells and thin films

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 method reduces manufacturing costs and effort while enabling scalable and automated production, minimizing assembly steps and errors, and optimizing installation space through reduced air and creepage distances.

Implementation Method 1

Insulating material is inserted into the attachment and the bending comb (5). The insulating material (12) electrically insulates the contact points (71, 72, 73) as well as the connection points (51) and the bent winding ends (8) from one another

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP3963694B1Method for producing a stator

Publication Date: 2025.12.10 SCHAEFFLER TECHNOLOGIES AG & CO KG

Figure 1
Figure 2~3
Figure 4~5

AI summary

The invention relates to a stator (1) and to a method for producing a stator (1). For this purpose, a connection element (3) is used which comprises a plurality of bus bars (41, 42, 43) and a star bar (40). The connection element (3) has a plurality of contact points (71, 72, 73) for the bus bars (41, 42, 43) and a plurality of contact points (41) of the star bar (40). The connection element (3) surrounds the winding ends (8) of the winding head (2). The winding ends (8) are bent relative to the contact points (71, 72, 73, 41) of the connection element (3) and contact the contact points (71, 72, 73, 41) electrically, by means of a bending ridge (5) which is positioned on the connection element (3).