Electric Machine Rotor with Segmented Magnetic Sectors

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Solution Overview

Problem

Conventional rotor production methods for alternators result in excessive material consumption, with the magnetic sheet metal used being twice the amount necessary for magnetic flux conduction, and components like armatures and inductors are often made from the same material, limiting optimization and increasing costs.

Innovation Solution

The rotor design involves cutting the magnetic sheet into sectors that can be made from different materials based on specific needs, with a support made of stamped sheet metal and sectors that can be offset for improved mechanical cohesion, allowing for reduced material usage and integration of additional components like balancing weights or diode bridges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional rotor production methods are used with complete tool cutting, then the magnetic circuit is produced, but material consumption is excessive (twice the material necessary for magnetic flux conduction)

Engineering Contradiction:
Improvemagnetic sheet metal consumptionVSAvoidmaterial actually necessary for magnetic flux conduction
Core Design Contradiction:
Loss of substanceVSQuantity of substance

Solution Approach 1:

The rotor is divided into separate functional components: an inductor with its own magnetic circuit and an armature with its own magnetic circuit. Each component is cut from separate sheet metal strips rather than from a single complete tool, allowing independent optimization of material usage for each component's specific magnetic flux requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different material grades and thicknesses can be selected for the inductor and armature based on their specific magnetic performance requirements. The inductor can use material optimized for high magnetic flux conduction, while the armature can use material optimized for its specific electromagnetic induction requirements, reducing overall material consumption.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If armature and inductor are made from the same material grade, then production is simplified, but material optimization and cost reduction are limited

Engineering Contradiction:
Improveproduction simplicityVSAvoidmaterial cost
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent applies different material grades to different components based on their specific requirements. The inductor can be made from sheet metal with one grade optimized for high magnetic permeability, while the armature can be made from sheet metal with another grade optimized for its electromagnetic requirements, allowing cost-effective material selection for each component.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the material parameters (grade, thickness, composition) independently for the inductor and armature sheets. This allows optimization of magnetic properties, mechanical properties, and cost for each component separately, rather than being constrained to a single material specification for both components.

Inventive Principle:
Principle #35Parameter changes

3Length of stationary object

If the support is made of conventional stacked sheets, then the magnetic circuit is formed, but the longitudinal size is excessive

Engineering Contradiction:
Improvesupport longitudinal sizeVSAvoidmagnetic circuit integrity
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The support is formed by bending a sheet metal strip into a curved or annular shape that conforms to the rotor's rotational geometry. This curved configuration provides the necessary structural support and magnetic circuit path while minimizing the longitudinal dimension of the support, allowing for a more compact overall rotor design.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2774250B1Rotor of an electric machine
Publication Date: 2020.11.18 MOTEURS LEROY SOMER
  • EP2774250B1 patent drawingFigure 2~6
  • EP2774250B1 patent drawingFigure 3~1
  • EP2774250B1 patent drawingFigure 7~10

AI summary

The invention relates to a rotor of a rotary electric machine, in particular for a flux-switching or wound-rotor machine, a mounting for installing the rotor on a shaft and a plurality of magnetic sectors, preferably in the form of a strip, attached to the mounting.