Lamination Stack Bonding via Non-Contact Adhesive Spraying

Solution Overview

Problem

Existing methods for manufacturing stacks of laminations face challenges such as high costs, limited robustness, difficulty with thin materials, restricted rotational angles, and unreliable stack strengths due to complex tooling and adhesive application limitations, particularly in achieving high-speed core production and integrating materials with varying thickness and quality.

Innovation Solution

A method utilizing a radically curing adhesive system applied without contact, combined with controlled pressure and heating, allows for the efficient bonding of laminations with varying thickness and quality, enabling high-speed production and flexible rotational angles by using methacrylate or anaerobic adhesives that cure rapidly and maintain strength at elevated temperatures, and employing an adhesive application system integrated within the pressing operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If linkage technology is used to join laminations, then the laminations are mechanically connected, but the tool complexity increases and robustness decreases

Engineering Contradiction:

Improvemechanical connection strengthVSAvoidtool complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical linkage system with a chemical bonding system using adhesive. Instead of using complex mechanical linkages to join laminations, the invention applies adhesive material to the lamination surfaces, allowing chemical bonding to occur. This substitution eliminates the need for complex linkage tools while achieving reliable mechanical connection through the adhesive bond.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If linkage technology is used to join laminations, then mechanical connection is achieved, but the method becomes less robust

Engineering Contradiction:

Improvemechanical connection strengthVSAvoidmethod robustness

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent replaces the mechanical linkage system with a chemical bonding system using adhesive. Instead of using complex mechanical linkages to join laminations, the invention applies adhesive material to the lamination surfaces, allowing chemical bonding to occur. This substitution eliminates the need for complex linkage tools while achieving reliable mechanical connection through the adhesive bond.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If adhesive is applied with contact methods, then bonding is achieved, but pressing rates are limited to 200-300 strokes per minute

Engineering Contradiction:

Improveadhesive bonding strengthVSAvoidpressing rate

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The patent replaces contact-based adhesive application with a spray application system. The adhesive is sprayed onto the lamination surfaces in a non-contact manner, eliminating the mechanical contact bottleneck. This allows the pressing operation to proceed at much higher rates (600+ strokes per minute) while still achieving adequate adhesive application and bonding.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Strength

If contact-based adhesive application is used, then bonding is achieved, but tool cleaning frequency increases

Engineering Contradiction:

Improveadhesive bonding strengthVSAvoidtool service time

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The patent replaces contact-based adhesive application with a spray application system. The adhesive is sprayed onto the lamination surfaces in a non-contact manner, eliminating the mechanical contact bottleneck. This allows the pressing operation to proceed at much higher rates (600+ strokes per minute) while still achieving adequate adhesive application and bonding.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach enables the fabrication of stacks with high strength and durability at economically competitive speeds, accommodating materials of different thicknesses and qualities, and allowing for flexible lamination orientation, while minimizing tool contamination and wear.

Implementation Method 1

A method utilizing a radically curing adhesive system applied without contact, combined with controlled pressure and heating, allows for the efficient bonding of laminations with varying thickness and quality

Methodology Applied

Scientific EffectRadical curing: Chemical Bonding

Implementation Method 2

use of methacrylate or anaerobic adhesives that cure rapidly and maintain strength at elevated temperatures

Methodology Applied

Scientific EffectMethacrylate curing: Photopolymerisation

Implementation Method 3

combined with controlled pressure and heating, allows for the efficient bonding of laminations

Methodology Applied

Scientific EffectThermal heating: Heating

Implementation Method 4

combined with controlled pressure and heating, allows for the efficient bonding of laminations

Methodology Applied

Scientific EffectMechanical pressure: Compression

Data Source

PatentUS11476739B2Method for the production of a stack of laminations

Publication Date: 2022.10.18 FEINTOOL INTERNATIONAL HOLDING AG

AI summary

In a method for manufacturing lamination stacks of controlled height in a tool, starting material is provided as continuous strip delivered from a coil or as an individual sheet. Laminations are punched from the starting material in several punching steps to a required contour of the laminations. A heat-curing adhesive is applied onto the laminations prior to performing a last punching step. The laminations are combined to a lamination stack. The laminations of the lamination stack are partially or completely heated in a lamination storage. The adhesive is liquefied by heating the lamination stack to build up adhesion and then solidified. Curing the adhesive at the liquefying temperature or solidifying the adhesive in the tool by cooling and subsequently heating the adhesive to a temperature below the liquefying temperature is possible so that the adhesive does not melt but undergoes further curing resulting in higher temperature stability.