Stator Winding Conductor Joining via Sequential Arc Welding

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Solution Overview

Problem

Existing methods for joining conductor segments in stator windings, particularly in high-power motors, face challenges in efficiently and accurately connecting multiple projecting ends without increasing the number of components or processes, especially in densely packed configurations with narrow pitches and many layers/rows, which complicates the installation and welding process.

Innovation Solution

A method involving the arrangement of tip-end pairs with specific ground electrodes and a welding electrode to establish electrical conduction and arc discharge between the conductor segments, allowing for the welding of pairs of projecting ends without the need for additional intermediate electrodes, thereby simplifying the process and maintaining high accuracy and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple conductor segments are densely packed in slots with narrow pitches to increase winding packing factor, then the winding packing factor increases and stator coil end length decreases, but the complexity of aligning and joining the projecting ends accurately increases significantly

Engineering Contradiction:
Improvewinding packing factorVSAvoidalignment precision of projecting ends
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The conductor segments are pre-assembled into groups with their straight portions arranged in parallel within slots before insertion. The projecting ends are preliminarily positioned and aligned during this pre-assembly stage, which simplifies the subsequent joining process by reducing the alignment complexity that would otherwise occur when dealing with densely packed segments individually

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stator winding is divided into multiple conductor segments that are sequentially joined. Each segment consists of straight portions and turn portions, allowing the winding to be constructed in manageable units. The projecting ends of these segmented conductors are joined in a systematic sequence, which manages the complexity of connecting multiple conductors in densely packed configurations

Inventive Principle:
Principle #1Segmentation

2Power

If the number of conductor segments and joining points increases to achieve high-power output, then the power output increases, but the number of welding processes and components required increases

Engineering Contradiction:
Improvepower outputVSAvoidnumber of welding processes and components
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

A single welding system is designed to perform multiple welding operations on different tip-end pairs sequentially. The welding system can move to different positions and weld multiple conductor segments using the same basic welding mechanism, eliminating the need for separate welding devices for each joining point and reducing overall system complexity

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

Solution Approach 2:

Multiple conductor segments are joined together to form unified stator windings, merging individual segments into a continuous electrical path. The welding system combines multiple welding functions into a single integrated device that can handle various joining operations, reducing the total number of components required

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If traditional welding methods are used for joining conductor segments in densely packed configurations, then the welding process becomes complex and time-consuming, but the joining reliability must be maintained

Engineering Contradiction:
Improvejoining reliabilityVSAvoidwelding speed and process efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Traditional mechanical alignment and positioning methods are replaced with a welding system that uses controlled arc discharge to join conductor segments. The welding process substitutes complex mechanical positioning with a more straightforward thermal joining method, improving both speed and reliability by reducing the sensitivity to minor alignment variations

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The welding parameters such as arc current, welding speed, and electrode position are optimized for densely packed conductor configurations. By adjusting these parameters, the welding process achieves reliable joins in narrow pitch arrangements without requiring excessively slow processing speeds, thus maintaining both reliability and productivity

Inventive Principle:
Principle #35Parameter changes

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 enables rapid and stable joining of conductor segments with high accuracy, reducing the complexity of the welding process and maintaining high efficiency even in densely packed configurations, thus supporting the downsizing and high efficiency of rotary electric machines.

Implementation Method 1

establishing electric conduction between the first ground electrode and the welding electrode via the first tip-end pair of the first paired conductor segments so as to weld the first tip-end pair (15a1) of the first paired conductor segments based on the electrical conduction therebetween

Methodology Applied
Scientific EffectArc discharge: Electric Arc

Implementation Method 2

the first tip-end pair (15a1) of the first paired conductor segments based on the electrical conduction therebetween

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP1936783B9Joining method of a plurality of conductor segment ends to form a stator winding
Publication Date: 2019.09.11 DENSO CORP
  • EP1936783B9 patent drawingFigure 1
  • EP1936783B9 patent drawingFigure 2
  • EP1936783B9 patent drawingFigure 3

AI summary

In a method, a first electrode is moved to contact with first paired ends of first paired conductor segments. Next, a second electrode is moved opposing the first paired ends Electric conduction is established between the first electrode and the second electrode via the first paired ends of the first paired conductor segments to weld the first paired ends of the first paired conductor segments based on the electrical conduction therebetween. Next, the second electrode is moved opposing second paired ends of second paired conductor segments while the first electrode is kept in contact with the first paired ends. Electric conduction is established between the first electrode and the second electrode via the welded first paired ends and the second paired ends to thereby weld the second paired ends of the second paired conductor segments based on the electrical conduction therebetween.