Composite Lamination Welding for Secure Motor Core Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for welding composite laminations with polymer layers face challenges such as outgassing, unsatisfactory welds, and damage to the damping layer, leading to separation and adverse effects on the properties of the lamination assembly, particularly in the manufacture of electric motors and generators.

Innovation Solution

A fusion welding process, including MAG, TIG, and laser beam welding, is used to package lamellae made of composite materials with a polymer layer resistant to aggressive oils, ensuring secure bonding without affecting magnetic, acoustic, and insulating properties, allowing for the use of existing equipment and minimal process modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If adhesive bonding is used to assemble laminations, then assembly is feasible for complex geometries, but assembly time and cost increase significantly

Engineering Contradiction:
Improveability to assemble complex geometriesVSAvoidassembly time
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent replaces adhesive bonding (chemical system) with friction stir welding (mechanical system). The friction stir welder uses a rotating tool to mechanically join laminations through friction heat and plastic deformation, eliminating the need for adhesives and significantly reducing assembly time while maintaining the ability to join complex geometries.

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

Solution Approach 2:

The patent changes the joining parameter from chemical bonding (adhesive curing time, temperature) to mechanical bonding (friction heat, plastic deformation). This parameter change enables faster assembly by eliminating adhesive application and curing steps, while the friction stir welding process parameters can be adjusted to accommodate complex geometries.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If adhesive bonding is used to assemble laminations, then assembly is feasible for complex geometries, but assembly cost increases

Engineering Contradiction:
Improveability to assemble complex geometriesVSAvoidassembly cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent replaces adhesive bonding (chemical system) with friction stir welding (mechanical system). The friction stir welder uses a rotating tool to mechanically join laminations through friction heat and plastic deformation, eliminating the need for adhesives and significantly reducing assembly time while maintaining the ability to join complex geometries.

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

Solution Approach 2:

The patent eliminates expensive adhesive materials and replaces them with a reusable friction stir welding tool. The mechanical joining process uses no consumable materials, reducing material costs while the tool can be reused for multiple assemblies, lowering overall manufacturing costs.

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

3Productivity

If conventional friction stir welding is used, then joining speed is high, but porosity and voids form in the joint

Engineering Contradiction:
Improvejoining speedVSAvoidjoint quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces dynamic motion (oscillation) of the friction stir welding tool in addition to rotation. This dynamic movement prevents material from being trapped and forming porosity, while maintaining high joining speed. The oscillation creates a more effective mixing and expulsion of material, eliminating voids without sacrificing productivity.

Inventive Principle:
Principle #15Dynamics

4Productivity

If conventional friction stir welding is used, then joining speed is high, but the process is unsuitable for composite materials

Engineering Contradiction:
Improvejoining speedVSAvoidsuitability for composite materials
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent adapts friction stir welding specifically for composite materials by modifying the tool design and process parameters. The tool incorporates features suitable for composite laminations, and the oscillation motion is specifically designed to handle the heterogeneous nature of composite materials, enabling high-speed joining while maintaining suitability for composites.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the welding parameters (rotation speed, oscillation amplitude, feed rate) to optimize for composite materials. These parameter adjustments enable the high-speed friction stir welding process to effectively join composite laminations without compromising either productivity or material compatibility.

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

The method provides secure bonding between lamellae, reducing structure-borne and airborne noise, enhancing motor efficiency, and enabling the use of thinner electrical steel strips with improved magnetic properties, while maintaining the integrity of the composite material's properties.

Implementation Method 1

The laminations may be joined together using a welding operation such as friction stir welding

Methodology Applied
Scientific EffectFriction welding: Friction Welding

Implementation Method 2

The tool is then moved along the interface between the two laminations, joining the laminations together

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentEP3900168B1Packing of laminations of a composite material by welding
Publication Date: 2026.05.06 THYSSENKRUPP STEEL EUROPE AG PATENTE PATENT DEPARTMENT

AI summary

The invention relates to a process for assembling a stack of at least two laminations made of a composite material using a gas-protected fusion welding operation, a lamination stack made according to said process, and the use of said lamination stack.