Ferromagnetic Lamination Cavity Structure for Insulation Retention

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Solution Overview

Problem

Conventional ferromagnetic lamination structures in electrical machines fail to effectively retain and seal insulating varnish, leading to moisture and water ingress, which damages insulation and reduces the mechanical and thermal performance of stator windings due to gaps and disbonding issues between different materials.

Innovation Solution

A cavity structure is introduced on the ferromagnetic boundary of the lamination, with grooves that form cavities within the winding slots, allowing a liquid insulating medium to be retained and solidified, creating a bonded intermediate elastic base that prevents peeling and enhances sealing, thereby improving the retention and filling efficiency of the insulating medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ferromagnetic lamination structures are used with flat inner walls in winding slots, then the manufacturing process is simple, but the insulating medium cannot be effectively retained and sealed, leading to moisture ingress and insulation damage

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidlamination structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lamination structure is segmented by introducing multiple grooves that divide the inner wall surface into distinct regions. These grooves create cavities that segment the insulating medium into retained portions, preventing it from flowing out while maintaining manufacturing feasibility through standardized groove patterns.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lamination structure incorporates a porous-like cavity system formed by grooves on the inner wall. These cavities act as retention spaces for the insulating medium, allowing the material to be held within the structure rather than flowing out, thereby improving sealing without requiring completely new material systems.

Inventive Principle:
Principle #31Porous materials

2Reliability

If insulating varnish is applied to fill gaps in stator windings, then insulation protection is improved, but the insulating medium flows out during varnish dripping and rotary baking processes, reducing filling efficiency

Engineering Contradiction:
Improveinsulation protectionVSAvoidinsulating medium loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The grooves are pre-formed on the lamination inner wall before the insulating medium is applied. This preliminary structural preparation creates retention cavities that prevent the insulating medium from flowing out during subsequent varnish dripping and rotary baking processes, significantly reducing material loss.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The grooves create localized retention zones at specific positions on the inner wall where the insulating medium is most needed. This local quality enhancement ensures that the insulating medium is retained precisely where it provides maximum insulation protection, rather than uniformly distributing it throughout the entire winding slot.

Inventive Principle:
Principle #3Local quality

3Reliability

If multiple ferromagnetic laminations are superposed to form the stator core, then the magnetic conductive member is formed, but fine gaps between lamination edges create hidden dangers of water entry and moisture adsorption

Engineering Contradiction:
Improveprotection against moisture ingressVSAvoidgap sealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The grooves on the inner wall act as intermediary retention spaces between the lamination structure and the insulating medium. These grooves capture and hold the insulating medium, creating a sealing effect that prevents moisture and water from entering through the gaps between laminations, without requiring additional sealing components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3471238B1Electric motor winding structure, electric motor magnetic conductive component, ferromagnetic lamination and electric motor
Publication Date: 2022.05.18 BEIJING GOLDWIND SCI & CREATION WINDPOWER EQUIP CO LTD
  • EP3471238B1 patent drawingFigure 1
  • EP3471238B1 patent drawingFigure 2~3
  • EP3471238B1 patent drawingFigure 4

AI summary

A ferromagnetic lamination, a magnetic conductive member of an electrical machine, an electrical machine having the magnetic conductive member of the electrical machine, a winding structure of an electrical machine, an electrical machine having the winding structure of the electrical machine, and an electric energy and magnetic energy conversion device are provided. The magnetic conductive member of the electrical machine includes winding slots, and multiple cavities are formed on an inner wall of each of the winding slots. With the magnetic conductive member of the electrical machine, a liquid insulating medium can be effectively retained and fixed by means of a cavity structure when an insulating treatment is performed on the magnetic conductive member of the electrical machine, and a rooted intermediate elastic base is formed at a ferromagnetic boundary after the liquid insulating medium is solidified, thereby effectively preventing the insulating medium from peeling, splitting or falling off.