Grounding Clip for Composite Guide Vanes

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Solution Overview

Problem

Current designs for grounding composite matrix guide vanes in gas turbine engines face challenges in achieving a robust electrical contact due to gaps between the guide vane, metallic sheath, and attachment fitting, which affects the integrity of the grounding path, especially when using adhesives and external grounding cables that can disrupt aerodynamics.

Innovation Solution

A grounding clip made of electrically conductive material, such as a flexible wire or ribbon, is attached to the metallic sheath and secured with an indent, allowing it to bridge the gaps between the guide vane, sheath, and attachment fitting, ensuring electrical continuity without external interference, and is designed to be encapsulated within the attachment fitting to prevent aerodynamic disruption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a metallic through-bolt is used to secure the guide vane, then the guide vane is mechanically secured to the attachment fitting, but intimate electrical contact is not achieved due to gaps and adhesive presence

Engineering Contradiction:
Improveelectrical grounding pathVSAvoidintimate electrical contact
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

A grounding clip made of electrically conductive material is introduced as an intermediary component between the metallic sheath and the metallic attachment fitting. The grounding clip bridges the gaps and ensures intimate electrical contact where the through-bolt alone cannot achieve reliable contact due to the presence of adhesive and manufacturing tolerances.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The grounding clip utilizes electrically conductive material that can be flexible (such as spring-loaded or corrugated conductive material) to accommodate the gaps and irregular surfaces between components, ensuring reliable electrical contact while maintaining mechanical flexibility for installation.

Inventive Principle:
Principle #40Composite materials

2Reliability

If an external jumper cable is used to ground the metallic sheath, then electrical grounding is achieved, but aerodynamic performance is adversely affected

Engineering Contradiction:
Improveelectrical grounding pathVSAvoidaerodynamic disruption
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The grounding function is extracted from the external jumper cable configuration and integrated into the internal attachment fitting structure. The grounding clip is positioned inside the attachment fitting, removing the need for external cables that would disrupt aerodynamics.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The grounding clip is nested within the attachment fitting structure, with the grounding clip positioned inside the attachment fitting and the metallic sheath inserted into the attachment fitting. This nested configuration allows the grounding path to be contained within the existing structural boundaries without external protrusions.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Strength

If adhesive is used to secure the guide vane, then mechanical bonding is achieved, but intimate electrical contact between components is compromised

Engineering Contradiction:
Improvemechanical bondingVSAvoidelectrical grounding path
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The grounding path is segmented into distinct contact points: the grounding clip contacts the metallic sheath at one location and the metallic attachment fitting at another location. This segmentation allows the grounding function to be established independently from the adhesive bonding between the guide vane and attachment fitting.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The grounding clip serves as an intermediary that establishes electrical contact pathways independent of the adhesive layer. By contacting the metallic sheath and metallic attachment fitting directly, the grounding clip creates reliable electrical paths that bypass the non-conductive adhesive material.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 grounding clip provides a reliable and aerodynamically neutral electrical connection, eliminating the need for separate grounding cables and reducing hardware, weight, and cost by integrating the grounding path within the existing attachment structure.

Implementation Method 1

A grounding path is required to enable static electricity generated by airflow over the guide vane to discharge to the engine, or to allow for a grounding path in the event of lightning strike on an engine

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The grounding clip can be a flexible material that biases against the metallic sheath

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3653837B1Grounding clip for bonded vanes
Publication Date: 2021.08.11 RTX CORP
  • EP3653837B1 patent drawingFigure 1~2

AI summary

A grounding clip (22) for an organic matrix composite guide vane (10) with a metallic sheath (20) comprises the organic matrix composite guide vane (10) including a body (12) having a leading edge (14) and a trailing edge (16) opposite the leading edge (14) and a root end (18) extending between the leading edge (14) and the trailing edge (16). The metallic sheath (20) is attached proximate the leading edge (14) and extends to the root end (18). A metallic attachment fitting (30) has a receiver (32) configured to receive the root end (18) of the organic matrix composite guide vane (10) for coupling the organic matrix composite guide vane (10) to the metallic attachment fitting (30. The grounding clip (22) is coupled to the sheath (20) proximate the root end (18), wherein the grounding clip (22) is electrically connected to the metallic attachment fitting (30) and the metallic sheath (20).