Laminated Core Arrangement with Round Sheets for Servo Motors

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing laminated core arrangement in servo motor armatures results in unmagnetized magnet material due to pole gaps and requires a longer core design to accommodate maximum magnet dimensions, leading to displacement issues during bandaging and adverse electromagnetic effects.

Innovation Solution

A laminated core arrangement with at least two part cores, where round individual sheets with a diameter less than or equal to the inner circle of polygonal sheets are used between part cores, eliminating indentations and allowing magnets to touch, reducing gaps, and enabling a compact design with reduced risk of magnet displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the laminated core is designed with maximum length to accommodate magnets with maximum dimensions, then magnets can be attached without collision at transitions, but gaps occur between individual magnets leading to bandage intrusion and magnet displacement

Engineering Contradiction:

Improvemagnet positioning stabilityVSAvoidcore length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The laminated core is divided into multiple part cores arranged in the axial direction. Each part core has a smaller axial length, which eliminates the need for excessive core length while maintaining magnet attachment stability. The segmentation allows magnets to be securely attached on each part core without the risk of collision or displacement at transitions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of extending the core length in the axial direction to accommodate magnet variations, the solution transitions to another dimension by using radial indentation (depth) to create magnet recesses. This dimensional change allows magnets to be securely positioned without requiring increased axial length, thereby preventing gaps and bandage intrusion.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of substance

If pole gaps are created to save unused magnet material, then magnet material waste is reduced, but electromagnetic performance deteriorates due to unmagnetized regions

Engineering Contradiction:

Improvemagnet material wasteVSAvoidelectromagnetic performance

Core Design Contradiction:

Loss of substanceVSPower

Solution Approach 1:

Round individual sheets are inserted between the part cores to create smooth, curved transitions. This curvature eliminates sharp edges and indentations that would otherwise create gaps or require pole gaps for material savings. The rounded geometry allows continuous magnet attachment around the circumference, maintaining electromagnetic performance while optimizing material usage.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameters of the individual sheets from polygonal with sharp edges to round with smooth curves. This parameter change eliminates the need for pole gaps by providing continuous surfaces for magnet attachment, thereby preventing material waste while maintaining full electromagnetic performance across the entire circumference.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If polygonal individual sheets with sharp edges are used, then manufacturing is simplified, but magnet attachment is problematic due to edges at transitions causing magnet overhang and displacement

Engineering Contradiction:

Improveindividual sheet productionVSAvoidmagnet attachment precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

Round individual sheets replace polygonal sheets with sharp edges. The curved geometry eliminates problematic edges at transitions, providing smooth surfaces for magnet attachment. This prevents magnet overhang and displacement while maintaining manufacturing simplicity through standardized round sheet production.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

Instead of modifying magnets to accommodate sharp polygonal edges, the invention inverts the approach by modifying the individual sheets to have round contours. This inversion eliminates the need for complex magnet adjustments while achieving precise magnet attachment without overhang or displacement issues.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS10396610B2Laminated core arrangement and electric machine with such a laminated core arrangement

Publication Date: 2019.08.27 SIEMENS AG

AI summary

A laminated core arrangement for an electric machine includes a laminated core having at least two part cores which are arranged in an axial direction. Each of the part cores has a plurality of polygonal individual sheets, with at least one of the individual sheets being round and disposed between the part cores. The at least one round individual sheet has a diameter which is less than or equal to an inner circle of the polygonal individual sheets. Permanently-excited magnets are disposed around a circumference of the laminated core.