Generator Shaft-to-Slip Ring Joint With Internal Excitation Cooling

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Solution Overview

Problem

Existing methods for connecting a generator rotating shaft and an external slip ring shaft in static excitation generators suffer from unreliable mechanical and electrical connections, poor heat dissipation, and instability under centrifugal force, particularly in high-speed operations, which can lead to circuit disconnection and reduced efficiency.

Innovation Solution

A connecting structure that moves the excitation conductive structure from the outer surfaces to the connecting end faces, using insulation components and a heat dissipation structure within a coaxial butt joint, with flexible conductive parts interconnected by an electric connection block and maintained by positioning spigot and sleeve pin structures, ensuring coaxiality and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the flexible conductive wire is disposed on the outer surfaces of the rotating shaft and slip ring shaft, then the heat dissipation is improved, but the mechanical strength and reliability are degraded under centrifugal force

Engineering Contradiction:
Improveheat dissipationVSAvoidconnection reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent inverts the conventional arrangement by moving the flexible conductive parts from the outer surfaces to the inner connecting cavity. This reversal places the conductive parts in a protected position where they are shielded from centrifugal force while still allowing heat dissipation through the cavity structure.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent nests the flexible conductive parts within the connecting cavity of the rotating shaft and slip ring shaft. This nesting arrangement protects the conductive parts from external mechanical stresses while maintaining thermal management through the cavity's internal structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If the flexible conductive wire is disposed on the outer surfaces, then the installation is simplified, but the mechanical strength and electrical connection reliability are insufficient

Engineering Contradiction:
Improveinstallation easeVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent segments the connection structure into distinct components: insulation components with mounting surfaces, flexible conductive parts, and an electric connection block. This segmentation allows each component to be optimized for its specific function while maintaining overall structural strength and electrical reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an electric connection block as an intermediary element that bridges the flexible conductive parts on either side of the connecting cavity. This intermediary ensures reliable electrical connection while accommodating the protected internal arrangement of the conductive parts.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the end faces are sealed for protection, then the mechanical protection is improved, but the heat dissipation of conductive rods is degraded

Engineering Contradiction:
Improvemechanical protectionVSAvoidheat dissipation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The connecting cavity serves multiple functions simultaneously: it provides mechanical protection for the flexible conductive parts, enables heat dissipation through its open structure, and facilitates electrical connection between the rotating shaft and slip ring shaft. This multi-functionality resolves the contradiction between protection and heat dissipation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 stable and reliable electrical connection, effective heat dissipation, and improved mechanical strength, preventing disconnection and excessive temperature, thereby enhancing the working reliability and lifespan of the excitation conductive structure.

Implementation Method 1

a heat dissipation structure penetrating into the connecting cavity from an outer surface of the rotating shaft or the slip ring shaft

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The heat dissipation structure releases the heat produced in the connecting cavity to reduce the temperature in the connecting cavity

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the flexible conductive parts arranged on the mounting surfaces and interconnected with the conductive rods, wherein a gap is maintained between the flexible conductive parts connected to the conductive rod on the rotating shaft side and the flexible conductive parts connected to the conductive rod on the slip ring shaft side

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4496193B1Connection structure for electric generator rotating shaft and external slip ring shaft
Publication Date: 2025.12.24 DONGFANG ELECTRIC MACHINERY
  • EP4496193B1 patent drawingFigure 1
  • EP4496193B1 patent drawingFigure 2
  • EP4496193B1 patent drawingFigure 3

AI summary

The present invention relates to the technical field of turbine-generator static excitation and provides a structure connecting a generator rotating shaft and an external slip ring shaft, which comprises a rotating shaft and a slip ring shaft in a coaxial butt joint, and butt joint faces each provided with a connecting cavity; insulation components provided in the connecting cavity and comprising an insulation part connected to each of the rotating shaft and the slip ring shaft, and the insulation parts comprising two mounting surfaces; a plurality of flexible conductive parts arranged on the mounting surfaces and interconnected with conductive rods, wherein a gap is maintained between the flexible conductive parts connected to the conductive rod on the rotating shaft side and the flexible conductive parts connected to the conductive rod on the slip ring shaft side, and the gap is filled with an electric connection block to conduct the flexible conductive parts on the rotating shaft side and the flexible conductive parts on the slip ring shaft side; and a heat dissipation structure penetrating into the connecting cavity from an outer surface of the rotating shaft or the slip ring shaft. According to the present invention, an excitation conductive structure is provided in the butt joint faces between the shafts to achieve a good protection effect on the excitation structure and guarantee a reliable electrical matching. In addition, an excess of internal temperature is prevented by use of the heat dissipation structure, thus improving the reliability of the overall connecting structure.