Rotor Extraction Guide Prevents Stator Damage

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Solution Overview

Problem

Existing methods for inserting or extracting a rotor into a stator in rotating electric machines are unreliable, leading to a risk of rotor rotation and potential damage due to unsecured connections using belts, which can fail to prevent the rotor from falling onto the stator.

Innovation Solution

A method involving a device with a first guide connected to the rotor's fan blades and a second guide fixed to the stator, using elongated apertures and screws to securely stabilize the rotor during extraction or insertion, preventing rotation and ensuring reliable operation by sliding the guides on each other.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If belts are used to connect guides to rotor shaft, then the device complexity is reduced, but the reliability of rotor guidance during extraction is worsened

Engineering Contradiction:
Improvedevice complexityVSAvoidreliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent removes the belts from the system entirely and replaces them with a direct mechanical connection between the guides and the rotor shaft. The guides are now rigidly attached to the shaft through keyways and set screws, eliminating the flexible belt connection that caused reliability issues while maintaining manageable device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent combines the guidance function and the rotational constraint function into a single integrated guide structure. The guides are directly mounted to the rotor shaft and work together with the stator guide to form a unified guidance system, eliminating the need for separate belt connections and improving overall reliability.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If rigid connection is used between guide and rotor shaft, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the rigid connection system into modular components: the guide body with integrated keyway, the separate key for transmitting torque, and adjustable set screws for securing the connection. This segmentation allows for reliable rigid connection while maintaining ease of assembly and disassembly, balancing reliability with manageable complexity.

Inventive Principle:
Principle #1Segmentation

3Reliability

If guides are used to prevent rotor rotation, then the reliability is improved, but the ease of operation is worsened

Engineering Contradiction:
ImprovereliabilityVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent incorporates adjustable set screws that allow the operator to dynamically control the tightness of the guide connection to the rotor shaft. During extraction operations, the connection can be tightened to prevent rotation, and when not in use, the connection can be loosened or disconnected, providing flexibility that improves ease of operation while maintaining reliability when needed.

Inventive Principle:
Principle #15Dynamics

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

The solution provides a reliable and stable mechanism for rotor extraction or insertion, preventing rotation and ensuring safe handling by maintaining a secure connection between the rotor and stator, thus preventing damage and ensuring reliable maintenance operations.

Implementation Method 1

these guides prevent rotation by sliding one on the other

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2675048B1Method and device for extraction or introduction of a rotor from or into a stator of an electric machine
Publication Date: 2022.08.10 GENERAL ELECTRIC TECH GMBH
  • EP2675048B1 patent drawingFigure 1~2
  • EP2675048B1 patent drawingFigure 3~4

AI summary

The method for extraction or introduction of a rotor (4) from or into a stator (2) of an electric machine (1) includes removing the fan blades (20) from the seats (19) of the rotor shaft (26), connecting a first guide (16) into the seats (19) of the removed fan blades (20), connecting a second guide (23) to the stator or to an element fixed to the stator (2), extracting or inserting the rotor (4) by sliding the first guide (16) on the second guide (23).