Stator Core Wedge Assembly for Controlled Bolt Locking

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Solution Overview

Problem

The existing process for securing stator core packs to building bolts in generators is unsafe and inefficient, with varying push-out forces leading to potential safety hazards and prolonged installation times due to the need for manual adjustment and large hammers.

Innovation Solution

A wedge assembly comprising opposing wedges with a ramped profile and a tensioning bolt is used to create a locking force between the stator core and building bolts, allowing for secure and efficient attachment using a pre-calibrated torque tool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the driven wedge is manually adjusted and hammered to be flush with the static wedge and filler piece, then the stator pack can be secured to the building bolts, but the installation process becomes time-consuming and creates safety hazards due to varying push out forces requiring large sledge hammers

Engineering Contradiction:
ImprovesafetyVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The wedge assembly incorporates a tensioning bolt that allows precise control of the wedging force through torque application, replacing the uncontrolled manual hammering process. This parameter control eliminates the need for large sledge hammers and reduces installation time while maintaining safety

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The manual hammering and adjusting process is replaced with a mechanical tensioning bolt system that applies controlled force through threading mechanics. This substitution eliminates the safety hazards of manual hammering while reducing installation time through predictable, controlled force application

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the driven wedge is cut and hammered to be flush with the static wedge and filler piece, then the stator pack can be secured, but the process requires large sledge hammers creating safety hazards due to overly tight wedges

Engineering Contradiction:
ImprovesafetyVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The complex manual process of cutting and hammering wedges is replaced with a simple tensioning bolt mechanism. The threaded bolt provides controlled, reversible force application that eliminates the need for cutting and hammering operations, reducing both safety risks and installation complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The wedge assembly is designed to be self-adjusting through the tensioning bolt mechanism. The bolt automatically applies the necessary force to secure the stator pack without requiring external hammering or cutting operations, simplifying the installation process while maintaining safety

Inventive Principle:
Principle #25Self-service

3Reliability

If opposing wedge sets are used to secure stator packs to building bolts, then the stator core can be attached to the stator frame, but the varying push out forces make the installation process unpredictable and dangerous

Engineering Contradiction:
Improveattachment reliabilityVSAvoidforce consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The tensioning bolt enables precise control and standardization of the wedging force through calibrated torque values. This eliminates the variability in push out forces, ensuring consistent and predictable attachment reliability across all stator packs while improving manufacturing precision

Inventive Principle:
Principle #35Parameter changes

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 wedge assembly ensures safe and rapid installation by maintaining consistent locking forces, reducing safety risks and installation time, while maintaining structural integrity.

Implementation Method 1

a set of opposing wedges configured to slide into a notch of a stator core and provide a locking force between the building bolt and the stator core

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The tensioning bolt sets the opposing wedges to create a locking force between the stator core and the building bolt

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3928414B1Generator, method for assembling a stator core and wedge assembly
Publication Date: 2026.01.14 SIEMENS ENERGY INC
  • EP3928414B1 patent drawingFigure 1~2
  • EP3928414B1 patent drawingFigure 3~5
  • EP3928414B1 patent drawingFigure 4

AI summary

A generator including a stator frame, a plurality of stator donuts including a plurality of circumferentially disposed notches, and a plurality of a wedge assemblies for mounting the stator donuts to a plurality of building bolts is presented. Each wedge assembly includes a set of opposing wedges. The set of opposing wedges are positioned within a notch in a stator donut to create a locking force between a building bolt and the stator core. The wedge assembly also includes a tensioning bolt to set the opposing wedges to a position creating the locking force between the stator core and the building bolt.