Transfer Tube Assembly With Conical Retention for Misalignment

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Solution Overview

Problem

Existing fluid transfer systems in gas turbine engines face challenges with misalignment, thermal growth, and fretting due to radial interference, which increase resistance and risk of damage during fluid transfer.

Innovation Solution

A transfer tube assembly with conical and chamfered surfaces that generate opposing axial reaction forces, allowing for smoother sliding and accommodating misalignment, featuring a drain sleeve with a stopper mechanism for axial retention and a sealed cavity for fluid containment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If radial interference is used to retain the transfer tube in the bore, then axial retention is improved, but resistance to axial sliding increases and fretting damage occurs

Engineering Contradiction:
Improveaxial retentionVSAvoidfretting damage and resistance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the geometric parameters of the retention interface by introducing conical surfaces with specific angles (e.g., 15-45 degrees) instead of cylindrical radial interference. This parameter change transforms the retention mechanism from radial to axial component-based, reducing fretting while maintaining retention force.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs conical surfaces with curved profiles instead of flat or cylindrical surfaces. The conical geometry with optimized angles allows for smoother contact and reduced stress concentration, minimizing fretting damage while maintaining reliable axial retention through the chromatic component engagement.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Manufacturing precision

If fixed geometric alignment is used between transfer tube and bore, then manufacturing precision is improved, but adaptability to thermal growth and misalignment deteriorates

Engineering Contradiction:
Improvealignment precisionVSAvoidaccommodation of thermal growth and misalignment
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic adaptability through conical surfaces that can accommodate angular misalignment and thermal growth. The conical geometry allows the transfer tube to self-adjust its position within the bore, maintaining seal integrity and proper alignment despite thermal expansion or installation variations, thus combining precision with adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent explicitly addresses thermal growth by designing the conical interface to accommodate expansion movements. The conical surfaces with appropriate angles allow for axial and angular adjustments that compensate for thermal expansion of the transfer tube or bore, preventing binding or loss of retention while maintaining manufacturing precision standards.

Inventive Principle:
Principle #37Thermal expansion

3Adaptability or versatility

If complex retention mechanisms are used to accommodate misalignment, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveaccommodation of misalignmentVSAvoidretention mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the complexity from multi-component retention mechanisms and replaces it with a simplified conical surface geometry. The single conical interface performs multiple functions: retention, misalignment accommodation, and fretting reduction, eliminating the need for separate adjustment mechanisms or multiple retention elements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The conical surface serves multiple functions simultaneously: it provides axial retention through chromatic components, accommodates angular misalignment, reduces fretting through smooth contact, and compensates for thermal growth. This multi-functionality in a single geometric feature reduces overall device complexity while maintaining high adaptability.

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 reduces resistance to axial sliding, minimizes fretting, and accommodates thermal growth and misalignment, ensuring reliable and efficient fluid transfer in gas turbine engines.

Implementation Method 1

the conical surface and the chamfered edge surface have an axial component along the longitudinal axis of the transfer tube

Methodology Applied
Scientific EffectConical surface geometry: Geometry

Data Source

PatentEP4086496B1Transfer tube assembly
Publication Date: 2024.06.26 PRATT & WHITNEY CANADA CORP
  • EP4086496B1 patent drawingFigure 1
  • EP4086496B1 patent drawingFigure 2
  • EP4086496B1 patent drawingFigure 3

AI summary

A transfer tube assembly (20) comprises a transfer tube (28a) slidably engaged in sealing engagement with a first component (24). The transfer tube (28a) has a shoulder (50) engageable with a stopper (48) for limiting relative axial movement between the transfer tube (28a) and the first component (24). The shoulder (50) has an abutment surface (54) facing a corresponding bore surface (56) of the first bore (34) of the first component (30). The abutment surface (54) and the bore surface (56) are configured to generate axially opposing reaction forces in response to the abutment surface (54) and the bore surface (56) contacting each other.