Segmented Generator Support Ring for Non-Destructive Stator Repair

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Solution Overview

Problem

Existing electrical generators in power plants face challenges in repairing the winding overhang due to the design of the support ring, which is typically one-piece and cannot be removed without destruction, necessitating a different installation method for repairs compared to new construction.

Innovation Solution

A split and tensionable support ring composed of individual ring segments that can be easily mounted and retrofitted, allowing for the replacement of the old support ring without destruction, using dowel pins and clamping plates to ensure precise fit and security, and adjustable cone angles for self-locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a one-piece support ring is used, then the structural strength and simplicity are improved, but the ease of repair deteriorates because the support ring cannot be removed without destruction

Engineering Contradiction:
Improvestructural strengthVSAvoidease of repair
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The support ring is divided into multiple ring segments that can be separately installed and removed. Each segment can be independently handled during repair operations, allowing the support ring to be disassembled without destruction while maintaining its structural integrity during operation

Inventive Principle:
Principle #1Segmentation

2Reliability

If the bar end cap protrudes radially beyond the supporting bars, then the electrical insulation is improved, but the ease of manufacture deteriorates because a one-piece support ring cannot be attached

Engineering Contradiction:
Improveelectrical insulationVSAvoidease of manufacture
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The support ring is segmented into multiple parts that can be installed separately. This allows the support ring to be fitted around the protruding bar end caps without requiring a single large opening, making the installation process feasible while maintaining the electrical insulation provided by the bar end caps

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The ring segments are designed to be installed in a nested manner around the protruding bar end caps. Each segment can be positioned and secured independently, allowing the complete support ring to be assembled around the existing bar end cap structure

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of repair

If a split support ring with multiple segments is used, then the ease of repair is improved, but the device complexity increases

Engineering Contradiction:
Improveease of repairVSAvoiddevice complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The support ring is divided into a limited number of segments (typically 2-4) that are connected by simple means such as bolts or interlocking features. This segmentation enables easy removal and reinstallation during repairs while keeping the design relatively simple and avoiding excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The ring segments are designed to work together as an integrated unit when assembled, providing the same structural function as a one-piece support ring. The segmentation is achieved through relatively simple connection mechanisms that do not significantly increase overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2146418B1Electrical generator for generating electricity in power plants and renovation method
Publication Date: 2011.07.20 SENSOPLAN
  • EP2146418B1 patent drawingFigure 1
  • EP2146418B1 patent drawingFigure 2~3

AI summary

The generator has a coil end (1) comprising radially inner-lying winding bars (2) and a radially outer supporting ring (7) lying at the winding bars. The supporting ring is a compound formed from individual rings such as an inner ring (8) and an outer ring (9), where the inner ring and the outer ring are braced against each other. A contact surface between the inner ring and the outer ring is conically designed in axial direction. Ring segment-shaped clamping plates (11) comprising bracing bolts (12) are provided for bracing the inner ring against the outer ring. An independent claim is also included for a method for restructuring a coil end of a stator of an electrical generator for power generation in a power station.