Stator Sealing Ring Centering Coil Winding

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Solution Overview

Problem

Existing stator manufacturing methods face challenges in accurately centering the coil winding with respect to the motor axis, leading to potential misalignment and increased manufacturing steps, which can result in reduced efficiency and increased risk of damage during assembly.

Innovation Solution

A stator design utilizing a sealing ring with a radially extending bearing surface that centers the coil winding by cooperating with the contact section, allowing for axial movement prevention and ensuring proper alignment during the molding process, thereby simplifying the production and ensuring precise centering of the coil winding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the coil winding is completely enclosed by end caps, housing and core structure with molding compound, then the coil winding is protected from vibrations and environmental influences, but the axial centering of the coil winding with respect to the motor axis cannot be checked after housing closure

Engineering Contradiction:
Improveprotection of coil windingVSAvoidcentering accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing ring is pre-installed on the housing before the coil winding is placed, creating a predetermined positioning structure that ensures accurate centering of the coil winding with respect to the motor axis before encapsulation occurs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sealing ring acts as an intermediary component between the housing and the coil winding, providing both sealing function and centering function, thereby eliminating the need for separate centering checks after housing closure

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If additional manufacturing steps such as alignment and balancing are added, then the centering precision is improved, but the manufacturing complexity and time increase

Engineering Contradiction:
Improvecentering accuracyVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The sealing ring combines multiple functions into a single component: sealing the coil winding, centering the coil winding axially, and providing a reference for alignment. This merging eliminates the need for separate alignment and balancing steps

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sealing ring serves multiple purposes simultaneously: it provides environmental sealing, axial centering, and alignment reference, thereby reducing the overall manufacturing process complexity while maintaining high precision

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

3Reliability

If the sealing ring extends radially from the front end section to the inner wall of the housing, then the coil winding is hermetically sealed and centered, but the production process requires precise positioning

Engineering Contradiction:
Improvehermetic sealingVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing ring's radial extension from the front end section to the inner wall of the housing creates self-aligning features that automatically position the coil winding correctly during assembly, reducing the need for external positioning aids

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3364529B1Stator for an electric motor
Publication Date: 2021.03.10 DR FRITZ FAULHABER GMBH & CO KG
  • EP3364529B1 patent drawingFigure 1
  • EP3364529B1 patent drawingFigure 2a~2c
  • EP3364529B1 patent drawingFigure 3a~3c

AI summary

The present invention relates to a stator (1) for an electric motor, comprising a housing (2) which accommodates a coil winding (3), wherein a molding compound (4) at least partially encloses the coil winding (3), and wherein a sealing ring (5) is arranged axially between a housing wall axially closing the housing (2) and the coil winding (3). The sealing ring (5) has a contact section (5a) that abuts circumferentially against an end section (7) of the coil winding (3) and extends radially at least from the end section (7) of the coil winding (3) to an inner wall (6) of a part of the housing (2) that circumferentially encloses the coil winding (3). The invention further relates to a method for manufacturing such a stator (1) in which a molding tool with a cylindrical mandrel centered with its longitudinal axis relative to a motor shaft (AA) of the electric motor is used.