In-situ Magnetization of Electric Machine Rotor Modules

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Solution Overview

Problem

The existing methods for activating and reactivating electric machines with magnetizable modules are cumbersome and costly, requiring specialized tools and facilities due to the strong forces involved, and often necessitate transporting the rotor to a factory for remagnetization, which is inefficient and time-consuming.

Innovation Solution

A method and apparatus that allows magnetizing the modules after the rotor is fitted to the stator, using a magnetizing device inserted within a frame that fits inside a stator segment seat, enabling magnetization with a precision positioning system to handle the modules safely and efficiently, allowing for on-site activation and reactivation without dismantling the machine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If magnetization is performed before assembling the rotor to the stator, then the modules can be properly magnetized, but the strong interacting forces require special tools and facilities, increasing device complexity and handling difficulty

Engineering Contradiction:
Improvemagnetization qualityVSAvoidassembly facility complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The magnetization is performed as a preliminary action after the rotor is assembled to the stator, rather than before assembly. The method enables the rotor to be assembled in its non-magnetized state, and then magnetized in situ using a magnetizing device that can be inserted through the stator, eliminating the need for complex special-purpose assembly facilities.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The magnetizing device is extracted through the stator to reach the rotor modules from the opposite side to the bearing. This approach removes the magnetizing operation from the complex assembly facility context and performs it in a simpler, accessible location after assembly is complete.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If the rotor is transported to a factory for remagnetization, then the modules can be reactivated, but the process requires dismantling and transporting the electric machine, increasing loss of time and productivity

Engineering Contradiction:
Improvereactivation capabilityVSAvoidreactivation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The electric machine performs its own magnetization function through the magnetizing device that can be inserted into the assembled rotor-stator structure. This self-service capability eliminates the need to transport the machine to an external factory for remagnetization, allowing the magnetization to be performed in situ and significantly improving reactivation efficiency.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The magnetization function is prepared in advance by designing the stator with a seat that accommodates the magnetizing device, enabling the reactivation to be performed quickly without dismantling or transporting the machine, thus improving productivity.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If magnetized modules are handled during assembly, then the rotor can be constructed, but the strong forces generated create safety hazards and require specialized handling procedures

Engineering Contradiction:
Improve rotor assemblyVSAvoidinteracting forces
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The magnetizing operation is extracted from the assembly process itself and performed separately after assembly is complete. The rotor is assembled in its non-magnetized state where no strong interacting forces are present, and then magnetized in situ, eliminating the safety hazards associated with handling magnetized modules during assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The assembly is completed as a preliminary action before magnetization. By assembling the rotor-stator structure first in its non-magnetized state, the harmful interacting forces are avoided during the assembly phase, and only appear after assembly is complete when the magnetization is performed safely in situ.

Inventive Principle:
Principle #10Preliminary action

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 eliminates the need for transporting magnetized rotors, reduces the risk of interacting forces during assembly, and allows for efficient on-site reactivation, saving time and costs by enabling magnetization after installation, thus improving the overall efficiency and safety of the process.

Implementation Method 1

each module of magnetizable material is made of material that can be magnetized to produce a magnetic field

Methodology Applied
Scientific EffectMagnetism: Magnetism

Implementation Method 2

a magnetizing device, which magnetizes the modules of magnetizable material with magnetizing flux of a given strength

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2282397B1Method and apparatus for activating an electric machine, and electric machine
Publication Date: 2018.01.24 WINDFIN BV
  • EP2282397B1 patent drawingFigure 1
  • EP2282397B1 patent drawingFigure 2
  • EP2282397B1 patent drawingFigure 3

AI summary

A method of activating an electric machine having a stator (2), and a rotor (3) which rotates about an axis (A1) with respect to the stator (2); the stator (2) having a plurality of stator segments (7) arranged about the axis (A1); the rotor (3) having modules (15) made of magnetizable material and arranged about the axis (A1); and the method including the steps of connecting the rotor (3) to the stator (2) by means of a bearing (16); and magnetizing the modules (15) of magnetizable material when the rotor (3) is connected to the stator (2).