Stator Slot Wedge Structure to Eliminate Finger End Plates

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Solution Overview

Problem

Existing electrical generators, particularly those in wind turbines, face inefficiencies due to expensive finger end plates and eddy-current losses, which affect mechanical support and Annual Energy Production (AEP).

Innovation Solution

A wedge design for stator teeth that provides mechanical support without finger end plates, featuring a 'T'-shaped structure with portions extending longitudinally and circumferentially to abut against multiple teeth, reducing eddy-current losses and enhancing coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If finger end plates are used to mechanically support stator teeth, then mechanical support is provided, but manufacturing cost increases and eddy-current losses occur

Engineering Contradiction:
Improvemechanical supportVSAvoideddy-current losses
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The invention merges the functions of the wedge and the end plate by extending the wedge longitudinally to provide mechanical support to the teeth, eliminating the need for separate finger end plates. This integration removes the source of eddy-current losses while maintaining structural support.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts and removes the finger end plates from the stator assembly, replacing their function with the extended wedge structure. This elimination of the end plates directly eliminates the eddy-current losses they caused.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If finger end plates are used to support stator teeth, then mechanical support is achieved, but manufacturing cost increases

Engineering Contradiction:
Improvemechanical supportVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention combines the support function into the wedge component itself, eliminating the need for separate end plate manufacturing. This reduces the total number of parts and manufacturing steps, thereby lowering manufacturing costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

By removing the finger end plates from the design, the invention eliminates their associated manufacturing costs. The simplified structure requires fewer components and assembly steps.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If conventional wedges are used, then winding protection is provided, but mechanical support for teeth is insufficient

Engineering Contradiction:
Improvewinding protectionVSAvoidmechanical support
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The wedge is segmented into multiple functional portions: a first portion for circumferential extension between teeth, a second portion for longitudinal abutment against tooth ends, and multiple wings for enhanced coupling. This segmentation allows each portion to perform its specific function optimally.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wedge extends in multiple dimensions beyond the traditional design - circumferentially between teeth and longitudinally along the tooth ends. This multi-dimensional extension provides both winding protection and enhanced mechanical support simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3646442B1Slot wedges for a stator of an electrical generator
Publication Date: 2025.07.23 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP3646442B1 patent drawingFigure 1~2
  • EP3646442B1 patent drawingFigure 3~4
  • EP3646442B1 patent drawingFigure 5~6

AI summary

Stator (20) for an electrical generator comprising: - a frame body (21) longitudinally extending along a longitu- dinal axis (Y) and including a stator yoke (22) and a plural- ity of teeth (33) radially protruding from the stator yoke (22) to respective tooth radial ends (38), each tooth extend- ing longitudinally between a first tooth longitudinal end (21a) and a second tooth longitudinal end (21b), - at least a wedges (40a-f). The wedge (40) comprises at least a first portion (41) and a second portion (42a-f), the first portion (41) and the second portion (42a-f) being shaped and dimensioned in such a way that, when the wedge (40) is attached to one of the tooth ra- dial ends (38), the first portion (41) extends longitudinally from one tooth longitudinal end (21a, 22a) and the second portion (42a-f) abuts against said one tooth longitudinal end (21a, 22a).