Stator Segment Coil Bending With Axial Displacement Restraint

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Solution Overview

Problem

Existing methods for manufacturing armatures face issues with positional offset of segment coils in the axial direction of the core during the bending of lead portions, leading to difficulties in tool insertion and affecting dimensions and shapes in subsequent steps.

Innovation Solution

A method involving the use of a restraining jig and a tool manipulated by a robot to insert segment coils into slots, with the restraining jig abutting bent portions to restrict axial movement and a clamp nipping roots of leg portions to prevent offset, followed by bending the final ends into predetermined shapes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wire ropes are bent around a model armature to form loops and welded, then the armature can be assembled, but the welding process causes deterioration of wire rope quality and increases production time

Engineering Contradiction:
Improvewire rope qualityVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the welding process from the assembly method and replaces it with a mechanical pressing connection. The connection portion of the wire rope is designed with a pressing structure that can be mechanically pressed to form a secure connection without welding, thereby extracting the harmful welding step while maintaining structural integrity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a pressing connection structure as an intermediary between wire rope segments. This pressing structure serves as a mediator that enables connection without direct welding, protecting the wire rope from welding-induced deterioration while still achieving secure mechanical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If conventional armature production methods are used, then assembly can be completed, but the process involves multiple steps including welding, insulation processing, and varnishing which reduces productivity

Engineering Contradiction:
Improveassembly completenessVSAvoidproduction efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent merges multiple conventional steps (wire rope bending, connection formation, and positioning) into a single integrated process. The pressing connection structure allows these operations to be combined, reducing the number of separate manufacturing steps while maintaining assembly completeness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The wire rope connection portions are pre-formed with pressing structures before final assembly. This preliminary preparation enables faster final assembly by eliminating the need for on-site welding and complex insulation processing, thereby improving productivity while ensuring proper assembly.

Inventive Principle:
Principle #10Preliminary action

3Strength

If wire ropes are welded to form connections, then structural strength can be achieved, but the welding process deteriorates wire rope quality and increases manufacturing complexity

Engineering Contradiction:
Improveconnection strengthVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extracts the welding operation from the connection process and replaces it with a mechanical pressing connection. The connection portion is designed with a pressing structure that achieves sufficient mechanical strength without the complexity of welding procedures, including insulation processing and varnishing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pressing connection structure uses simpler, less durable materials and methods compared to welding, accepting that the connection may have limited service life in exchange for dramatically reduced manufacturing complexity and eliminated welding-related quality deterioration.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP4472043B1Method of manufacturing armature
Publication Date: 2026.04.22 NHK SPRING CO LTD
  • EP4472043B1 patent drawingFigure 1
  • EP4472043B1 patent drawingFigure 2A~2C
  • EP4472043B1 patent drawingFigure 3

AI summary

The present disclosure effectively suppresses displacement of segment coils in the axial direction of a core when the ends of segment coil leg parts are bent. This production method produces a stator (10) that comprises a plurality of segment coils (40) that are annularly arranged in a plurality of layers (46A, 46B, 46C) that overlap in the radial direction of a stator core (14). The production method involves a tool (74) that has teeth (76A, 76B, 76C) being moved by a robot manipulator (72) and the teeth (76A, 76B, 76C) being inserted between the ends of leg parts (42) of the layers (46A, 46B, 46C). The ends that engage the teeth (76A, 76B, 76C) are thereby bent so as to be substantially crank-shaped. Before the teeth (76A, 76B, 76C) are inserted between the ends, a restraining jig (86) is inserted between bend parts (44) of the segment coils (40) of the layers (46A, 46B, 46C) and an end surface (14A) of the stator core (14) that is on one side in the axial direction.