Embedded Conductors in Composite Raft for Gas Turbine Wiring

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Solution Overview

Problem

Conventional wiring harnesses in gas turbine engines are bulky, heavy, and difficult to manipulate, with complex assembly and maintenance processes, and are susceptible to mechanical damage, limiting their efficiency and reliability.

Innovation Solution

A method of producing a rigid raft with embedded electrical conductors, where a pre-cured base layer is inspected separately for defects before laying up the conductors, allowing for a simpler structure, reduced material variability, and customization of the cover layer, with the conductors being embedded in a composite material that can include flexible printed circuit boards and a non-composite protective cover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional wiring harnesses are used in gas turbine engines, then electrical components can be connected and controlled, but the harnesses become bulky, heavy, and difficult to manipulate

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidease of manipulation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies composite materials by embedding electrical conductors within a rigid composite raft structure. The raft is formed from composite material layers (such as carbon fiber reinforced polymer) that provide structural strength while encapsulating the electrical harness, transforming the flexible but bulky conventional harness into a rigid, integrated composite structure that is easier to handle and install.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent merges the electrical harness with the structural raft by embedding the conductors directly into the composite material during manufacturing. This integration combines the electrical connection function with the structural support function, eliminating the need for separate harness assembly and manipulation while maintaining electrical reliability.

Inventive Principle:
Principle #5Merging (Combining)

2Object-affected harmful factors

If conventional wiring harnesses with protective sleeves and braiding are used, then mechanical damage can be reduced, but the harnesses become even heavier and more difficult to manipulate

Engineering Contradiction:
Improvemechanical damage protectionVSAvoidharness weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of stationary object

Solution Approach 1:

The rigid composite raft structure provides inherent mechanical protection to the embedded electrical conductors. The composite material layers (such as carbon fiber reinforced polymer) offer high strength-to-weight ratio and damage resistance, eliminating the need for additional heavy protective sleeves and braiding while reducing overall weight compared to conventionally protected harnesses.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The protective function is merged into the structural raft itself. The composite material serves dual purposes: providing structural support for the engine component and simultaneously protecting the embedded electrical conductors from mechanical damage, thereby eliminating redundant protective layers and reducing weight.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If conventional wiring harnesses with multiple components are assembled, then electrical connections can be established, but the assembly process becomes complicated and time-consuming

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidassembly speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The electrical conductors are pre-positioned and embedded within the composite raft during the raft manufacturing process, before the raft is installed in the engine. This preliminary integration of the electrical system into the structural component eliminates the need for separate harness assembly and connection steps during engine assembly, significantly improving productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The electrical connection function is merged with the structural raft manufacturing process. By embedding the conductors during composite layup and curing, the patent combines two previously separate processes (raft fabrication and electrical harness installation) into one, reducing assembly complexity and time while maintaining connection reliability.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of repair

If conventional wiring harnesses are removed and refitted during maintenance, then repairs can be performed, but the process accounts for significant operation time and potential assembly errors

Engineering Contradiction:
Improvemaintenance accessibilityVSAvoidmaintenance time
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The patent enables segmentation of the electrical system by allowing the rigid raft to be removed as a single integrated unit during maintenance. The embedded conductors remain fixed within the raft structure, so the entire electrical assembly can be removed and refitted together, reducing maintenance time and minimizing assembly errors compared to disassembling individual harness components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrical conductors and structural raft are merged into one integrated component that can be removed and installed as a single unit during maintenance. This integration eliminates the need to carefully disconnect and reconnect individual wire harnesses, significantly reducing maintenance time and the risk of assembly errors while maintaining ease of repair.

Inventive Principle:
Principle #5Merging (Combining)

5Ease of manufacture

If co-curing of pre-impregnated layers and electrical harness is performed in one procedure, then a complete rigid raft can be produced, but inspection becomes difficult and defects may be hidden

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidinspection difficulty
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies preliminary action by inspecting the cured base layer for defects before laying up the electrical conductors and completing the raft assembly. This sequential approach allows non-destructive testing (such as ultrasonic or radiographic inspection) to be performed on the structural layers alone, when defects are most detectable, before the conductors are embedded and would obscure the inspection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The manufacturing and inspection process is segmented into stages: first curing and inspecting the base layer, then adding and inspecting the cover layer with embedded conductors. This segmentation allows inspection at optimal points in the manufacturing process, improving defect detection capability while maintaining manufacturing efficiency.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3437844B1Method for producing a rigid raft
Publication Date: 2021.12.01 ROLLS ROYCE PLC
  • EP3437844B1 patent drawingFigure 1
  • EP3437844B1 patent drawingFigure 2
  • EP3437844B1 patent drawingFigure 3A~3D

AI summary

A method is provided of producing a rigid raft comprising electrical conductors enclosed in the raft. The method includes: providing a cured, composite material base layer; laying up electrical conductors on the base layer; and overlaying the laid-up electrical conductors with a cover layer, thereby producing a rigid raft in which the electrical conductors are enclosed in the raft.