Insulated Gearbox Feedthrough Tube for Wind Turbine Stray Currents

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Solution Overview

Problem

Integrated drive trains in wind turbines face issues with stray currents, which can cause damage to gears and rolling bearings due to voltage flashovers, and existing insulation measures are inadequate, especially in medium-speed applications where space is limited.

Innovation Solution

A rotationally symmetrical feedthrough tube made of an electrical non-conductor, such as polyamide, is used to transmit electrical or hydraulic supply lines through the gearbox, with a fixing means that provides electrical insulation between the tube and the transmission components, preventing leakage currents and accommodating high torque transmission with minimal installation space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adequate insulation measures are taken to prevent stray currents, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprevention of damage from stray currentsVSAvoidinsulation measures
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the fixing function and insulation function into a single integrated fixing element. The fixing element is made of electrically insulating material that simultaneously secures the feedthrough tube to the gearbox housing and electrically isolates it from conductive components, eliminating the need for separate insulation components and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fixing element serves multiple functions: it mechanically secures the feedthrough tube to the gearbox housing, provides electrical insulation between the feedthrough tube and conductive components, and maintains structural integrity under torque loads. This multi-functionality reduces the number of components needed while improving reliability.

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

2Reliability

If insulation measures are implemented in medium-speed drive trains, then reliability is improved, but installation space requirements increase

Engineering Contradiction:
Improveprotection against voltage flashoversVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The fixing element merges mechanical attachment and electrical insulation functions into a single compact component that integrates directly into the existing gearbox structure. This eliminates the need for additional insulation components that would occupy extra space, making it particularly suitable for space-constrained medium-speed drive trains.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fixing element can be designed as a thin-walled or compact structure made of insulating material that provides adequate electrical isolation without requiring large volumes. The insulating material forms a compact barrier between conductive components while maintaining structural strength.

Inventive Principle:
Principle #30Flexible shells and thin films

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 effectively prevents damage from stray currents by ensuring electrical insulation between the generator and transmission, maintaining structural integrity and operational efficiency in integrated drive trains while compensating for space constraints.

Implementation Method 1

the fixing element consists of an electrically insulator, such as polyamide. The fixing element thus electrically isolates the feedthrough tube and the gearbox component in which the feedthrough tube is fixed by means of the fixing element from each other

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentEP3795825B2Gear box arrangement for wind turbine with insulated feed-through pipe
Publication Date: 2024.07.24 ZF FRIEDRICHSHAFEN AG
  • EP3795825B2 patent drawingFigure 1~2

AI summary

The invention relates to an arrangement comprising a gearbox, a feedthrough tube (103), and a fixing means (101); wherein the feedthrough tube (103) is fixed in the gearbox by means of the fixing means (101). The fixing means (101) consists of an electrically insulator.