Segmented Rotor Protector for Axial Magnet Retention

Solution Overview

Problem

Existing rotor designs for electrical machines are limited in their ability to securely protect permanent magnets from axial displacement due to interference contours and mechanical vibrations, making it difficult to fit traditional ring-shaped protectors and complicating the installation of magnets.

Innovation Solution

A rotor design featuring a motor shaft with a distributed arrangement of permanent magnets secured by a protector comprising at least two annular segments, which can be fitted even in areas with interference contours, providing axial protection and flexibility in construction, and can be produced from low magnetic permeability materials to prevent magnetic flux short-circuiting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional ring-shaped protector is used to secure magnets against axial displacement, then the magnets are protected from axial forces, but the protector cannot be fitted on shafts with interference contours and the construction flexibility is reduced

Engineering Contradiction:

Improveprotection of magnets against axial displacementVSAvoidconstruction flexibility of rotor

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The protector is divided into multiple annular segments that can be fitted separately onto the shaft. This segmentation allows the protector to overcome interference contours on the shaft surface, as each segment can be positioned and secured independently, thereby maintaining construction flexibility while providing reliable axial protection for the magnets.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If a one-piece ring protector is used, then the structure is simple, but it cannot be fitted in areas with interference contours

Engineering Contradiction:

Improvestructure of protectorVSAvoidfitting process of protector

Core Design Contradiction:

Device complexityVSEase of manufacture

Solution Approach 1:

The protector is divided into multiple annular segments that can be fitted separately onto the shaft. This segmentation allows the protector to overcome interference contours on the shaft surface, as each segment can be positioned and secured independently, thereby maintaining construction flexibility while providing reliable axial protection for the magnets.

Inventive Principle:

Principle #1Segmentation

3Reliability

If the rotor is subjected to severe impacts and vibrations, then the electrical drive system may fail, but using a segmented protector enhances reliability under such conditions

Engineering Contradiction:

Improveoperation under mechanical vibrationsVSAvoidstructure of protector

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protector is divided into multiple annular segments that can be fitted separately onto the shaft. This segmentation allows the protector to overcome interference contours on the shaft surface, as each segment can be positioned and secured independently, thereby maintaining construction flexibility while providing reliable axial protection for the magnets.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11233431B2Protector for a rotor of an electrical machine

Publication Date: 2022.01.25 WITTENSTEIN SE

AI summary

A rotor for an electrical machine, comprising a motor shaft and a distributed arrangement of permanent magnets on said motor shaft, which are secured against displacements in the axial direction of the rotor by a protector, wherein the protector comprises at least two annular segments.