Oil-Cooled Carbon Seal with Annular Channel for Uniform Heat Dissipation

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Solution Overview

Problem

Existing carbon seal systems in gas turbine engines face challenges in efficiently dissipating frictional heat generated at the sliding interface, particularly due to uneven cooling distribution and potential thermal expansion issues.

Innovation Solution

The implementation of an annular channel in the seat piece of the carbon seal system, which extends radially outward and merges into a plenum, provides a more uniform circumferential cooling effect by ensuring consistent oil flow and residence time, thereby enhancing heat dissipation and reducing thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional oil cooling passageways are used in carbon seals, then heat dissipation is achieved, but uneven cooling distribution and thermal expansion issues occur

Engineering Contradiction:
Improvecooling distribution uniformityVSAvoidthermal expansion control
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent introduces a plenum chamber that distributes cooling oil to multiple cooling passages at different locations around the seal interface. This ensures that different regions of the seal experience uniform cooling, preventing localized thermal expansion and maintaining consistent sealing pressure across the entire interface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cooling system is divided into multiple independent cooling passages that radiate from a central plenum chamber. This segmentation allows for more precise control of cooling oil distribution to different areas of the seal, ensuring uniform heat dissipation and preventing uneven thermal expansion that would occur with a single centralized cooling passage.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If oil cooling is applied to the seal interface, then frictional heat is dissipated, but oil flow consistency and residence time vary

Engineering Contradiction:
Improvefrictional heat dissipationVSAvoidcooling efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The plenum chamber serves as a preliminary distribution point that receives cooling oil before it is distributed to the various cooling passages. This preliminary action ensures that oil is evenly distributed to all cooling zones before contact with the seal interface, optimizing residence time and cooling efficiency across the entire seal surface.

Inventive Principle:
Principle #10Preliminary action

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

This configuration achieves improved heat dissipation and reduced wear by ensuring consistent and uniform cooling across the seal interface, thereby enhancing the operational efficiency and longevity of the gas turbine engine's carbon seal systems.

Implementation Method 1

the oil that flows through the seat cools the seat

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

oil cooling... oil passes through passageways in the seat... oil flows through the seat

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the oil may be delivered through a nozzle and slung radially outward by the rotating component

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 4

the annular carbon seal is spring biased into engagement with an annular seat

Methodology Applied
Scientific EffectElastic force: Spring

Implementation Method 5

The sliding engagement causes frictional heating

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4160059B1Oil-cooled carbon seal
Publication Date: 2025.04.09 RTX CORP
  • EP4160059B1 patent drawingFigure 1
  • EP4160059B1 patent drawingFigure 1A
  • EP4160059B1 patent drawingFigure 2

AI summary

A seal system (100) has: a first member (102); a seal (104) carried by the first member (102) and having a seal face (106); and a second member (110) rotatable relative to the first member (102) about an axis (500). The second member (110) has: a seat (112), the seat (112) having a seat face (114) in sliding sealing engagement with the seal face (106); and a circumferential array of passageway legs. The second member (110) further has an annular channel axially spaced from the seat face (114), the passageway legs connected to the annular channel.