Stator Interconnection Device with Plastic Encapsulation

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Solution Overview

Problem

Existing stator connection devices for electrical machines face challenges in preventing electrical voltage breakdowns and short circuits, particularly at the edge regions of recesses, and require space-saving and cost-effective solutions that enhance voltage resistance.

Innovation Solution

A stator connection device featuring axially stacked ring disk connecting conductors with different-sized fastening openings, encapsulated in plastic, forming a metal-plastic composite part, which increases the air and creepage distance between conductors and enhances electrical dielectric strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If connecting conductors are stacked closely together to save space, then the axial length is reduced, but the risk of electrical voltage breakdown and short circuits increases

Engineering Contradiction:
Improveaxial length of interconnection deviceVSAvoidvoltage resistance between conductors
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

An insulating body is introduced as an intermediary element between the connecting conductors. This insulating body extends in the axial direction and provides electrical insulation between adjacent conductors, allowing them to be stacked closely together without risking voltage breakdown. The insulating body acts as a mediator that enables close stacking while maintaining electrical isolation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The interconnection device combines conducting materials (the connecting conductors) with insulating materials (the insulating body) to form a composite structure. This composite design allows the conductive parts to be closely stacked for space efficiency while the insulating parts maintain electrical isolation, resolving the contradiction between compactness and voltage resistance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If additional insulation measures are added to prevent voltage breakdown, then voltage resistance is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvevoltage resistance between conductorsVSAvoidstructural complexity of interconnection device
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The insulating body is designed to combine multiple functions: it provides electrical insulation between conductors, supports the axial stacking arrangement, and facilitates the overall structure of the interconnection device. By merging these functions into a single component, the design avoids the need for separate insulation elements, reducing overall complexity while maintaining voltage resistance.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If connecting conductors are stacked axially to reduce space, then the axial length is reduced, but the assembly precision requirements increase

Engineering Contradiction:
Improveaxial length of interconnection deviceVSAvoidalignment precision of mounting openings
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The insulating body is designed with predetermined geometric features, including recesses that align with the mounting openings of the connecting conductors. This preliminary design of the insulating body ensures that when the conductors are stacked, their mounting openings are properly aligned, reducing the precision requirements during assembly compared to direct conductor-to-conductor stacking.

Inventive Principle:
Principle #10Preliminary action

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

The solution provides improved voltage resistance and reduced assembly complexity, enabling a space-saving and cost-effective interconnection device with enhanced electrical performance and simplified production.

Implementation Method 1

The connecting conductors are axially spaced from one another and encapsulated with a plastic, thereby forming a metal-plastic composite part... increases the air and creepage distance between conductors and enhances electrical dielectric strength

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

The connecting conductors are axially spaced from one another and encapsulated with a plastic... increases the air and creepage distance between conductors and enhances electrical dielectric strength

Methodology Applied
Scientific EffectCreepage distance enhancement: Dielectric

Data Source

PatentEP3646443B1Stator interconnection device for a rotating electrical machine
Publication Date: 2022.03.02 ZF FRIEDRICHSHAFEN AG
  • EP3646443B1 patent drawingFigure 1
  • EP3646443B1 patent drawingFigure 2a~2c
  • EP3646443B1 patent drawingFigure 3

AI summary

An interconnection device (38) for a stator winding of a rotating electric machine (10) is proposed, comprising a plurality of connecting conductors (52, 54, 56) which are in the form of annular discs, are stacked in a coaxial manner and are electrically insulated from one another. Each connecting conductor (52-56) has a plurality of fastening openings (522-562), distributed in the circumferential direction, for fixing the interconnection device (38) to a stator (16), and the connecting conductors (52-56) are stacked in such a way that the fastening openings (522-562) are positioned axially with respect to one another in sets and substantially cover one another so as to form a fastening passage (60). According to the invention, the connecting conductors (52-56) are spaced apart from one another axially and are overmolded with a plastic (58), as a result of which the interconnection device (38) forms a metal/plastic composite part. At least two types of fastening opening (522-562) are provided with a different opening width, which form larger fastening openings (522a-562a) and smaller fastening openings (522b-562b), wherein a larger fastening opening (522a-562a) and a smaller fastening opening (522b-562b) are formed on a fastening passage (60) in two adjacent connecting conductors (52-56), and wherein an annular space (62), which extends from an edge of the larger fastening opening (522a) to an edge of the smaller fastening opening (522b), is filled with the plastic (58). A stator (16) and an electric machine (10) comprising such an interconnection device (38) are also proposed.