Iron Core Assembly With Insulation Protrusions for Compact Motors

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Solution Overview

Problem

Existing motor designs face challenges in miniaturization and weight reduction due to the need for thicker insulating skeletons to maintain creepage distance, leading to increased motor resistance and volume, which affects energy efficiency.

Innovation Solution

An iron core assembly design with insulation protrusions covering both sides of the iron core blocks and mounting grooves at the end surfaces, reducing the thickness of the insulating skeletons while maintaining sufficient creepage distance, thereby reducing the motor's axial length and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thickness of the insulating skeleton is increased to ensure sufficient creepage distance, then the insulation reliability is improved, but the motor volume and weight increase

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidmotor volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The insulating skeleton is segmented into multiple parts: a base insulating skeleton and additional insulating protrusions or extensions. These segmented insulating structures are strategically positioned to provide creepage distance coverage without requiring a uniform increase in the entire skeleton's thickness, thus reducing overall motor volume while maintaining insulation reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of increasing insulation thickness only in the axial direction (one dimension), the patent utilizes multi-dimensional insulation structures including radial extensions and circumferential coverage. The insulating skeleton extends in multiple directions (axial, radial, and circumferential) to provide sufficient creepage paths without increasing the motor's axial length excessively, effectively using dimensional optimization to resolve the contradiction.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the thickness of the insulating skeleton is increased to ensure sufficient creepage distance, then the insulation reliability is improved, but the motor weight increases

Engineering Contradiction:
Improveinsulation reliabilityVSAvoidmotor weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The insulating skeleton is divided into functional segments with different thicknesses and material densities. Critical insulation areas have sufficient thickness for creepage distance, while non-critical areas use thinner or lighter insulating structures, reducing overall weight while maintaining required insulation reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite insulating structures combining different materials with varying properties. High-performance insulation materials are used only where creepage distance is critical, while lighter materials or thinner structures are used in less critical areas, optimizing the weight-strength-insulation balance.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the insulating skeleton thickness is increased, then the creepage distance is sufficient, but the coil circumference increases and motor resistance increases

Engineering Contradiction:
Improvecreepage distanceVSAvoidmotor resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The insulating skeleton exhibits local quality variations with different thicknesses and material properties at different locations. Thicker insulation is provided only where creepage distance is most critical (near high-voltage regions), while thinner insulation suffices in low-voltage areas, minimizing the increase in coil circumference and motor resistance while ensuring adequate creepage paths where needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The insulating skeleton is designed with pre-positioned insulating protrusions and extensions that are formed during the molding process. These preliminary insulating structures are integrated into the winding groove design, ensuring creepage distance requirements are met before winding installation, thereby avoiding the need for additional insulation layers that would increase coil circumference and resistance.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If the insulating skeleton thickness is increased, then the creepage distance is sufficient, but the motor volume increases

Engineering Contradiction:
Improvecreepage distanceVSAvoidmotor volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The insulating structures are nested within the existing motor geometry. The insulating skeleton is integrated into the stator core and winding groove structure, with insulating protrusions nested within available spaces rather than adding external volume. This nesting approach provides sufficient creepage distance while minimizing overall motor volume increase.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes multi-dimensional space utilization where insulating structures extend radially and circumferentially in addition to axially. By distributing insulation coverage across multiple dimensions rather than concentrating it in the axial direction, the motor's overall volume (particularly axial length) is minimized while still providing adequate creepage paths through spatial optimization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3955432B1Iron core assembly, electric motor, compressor and vehicle
Publication Date: 2025.09.24 GUANGDONG WELLING AUTO PARTS CO LTD
  • EP3955432B1 patent drawingFigure 1~2
  • EP3955432B1 patent drawingFigure 3~4
  • EP3955432B1 patent drawingFigure 5~6

AI summary

The present invention provides an iron core assembly, a motor, a compressor and a vehicle. The iron core assembly comprises: an iron core body, wherein the iron core body comprises a plurality of iron core blocks, and a mounting groove is provided at an edge of at least one end face of each iron core block: and a plurality of insulating skeletons, wherein each iron core block is arranged between two insulating skeletons and is distributed in the two insulating skeletons at two ends of one iron core block, and an end face, facing the iron core block, of at least one of the insulating skeletons is provided with insulating protrusions used for wrapping two sides of the iron core block, the insulating protrusions matching the mounting groove. The insulating protrusions wrap the two sides of the iron core block, such that a sufficient creepage distance between a winding of a motor and the iron core assembly can be ensured, the thickness of a part, which covers the end face of the iron core block and extends along the end face, of the insulating skeleton is effectively reduced, and the length of the iron core assembly in an axial direction of the iron core body is reduced, thereby facilitating the reduction of the size and weight of the motor, and having high insulating reliability.