Stator Vane Bearing Seal with Labyrinth Ridges for Leakage Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In gas turbine engines, the adjustable bearing journals of stator vanes often result in leakage flows due to component tolerances and wear, reducing the mass flow within the engine core.

Innovation Solution

A stator vane assembly with a sealing element featuring radially extending sealing ridges and nonlinear slots is used to create a labyrinth seal within the bearing opening, reducing or eliminating leakage flows by deflecting air and accommodating thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a bearing journal is provided with clearance for rotatable mounting, then ease of operation and adjustment are improved, but leakage flow increases and mass flow decreases

Engineering Contradiction:

Improveadjustability of bearing journalVSAvoidmass flow in engine core

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

A sealing element is introduced as an intermediary component between the bearing journal and the bearing opening. This sealing element has a sealing surface that contacts the bearing journal while being mounted in the bearing opening, thereby mediating between the need for clearance (ease of operation) and the need to prevent leakage (mass flow maintenance). The sealing element allows rotational movement while blocking the leakage path.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing element functions as a flexible barrier that can accommodate the clearance necessary for bearing journal rotation. The sealing surface of the sealing element maintains contact with the bearing journal during rotation, creating a flexible seal that prevents leakage while allowing the bearing journal to rotate within the bearing opening.

Inventive Principle:

Principle #30Flexible shells and thin films

2Quantity of substance

If a sealing element is added to reduce leakage flow, then mass flow is improved, but device complexity increases

Engineering Contradiction:

Improvemass flow in engine coreVSAvoidcomplexity of bearing journal assembly

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The sealing element is designed to perform multiple functions: it seals the bearing opening to prevent leakage, allows rotational movement of the bearing journal, and can be mounted in a relatively simple manner in the bearing opening. By combining these functions in a single component, the overall device complexity is minimized while achieving the mass flow improvement.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If the sealing element is made as a single solid piece, then sealing effectiveness is improved, but ease of assembly and thermal expansion accommodation deteriorate

Engineering Contradiction:

Improvesealing effectivenessVSAvoidassembly ease and thermal expansion

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing element is segmented by providing at least one longitudinal slot that divides the sealing element into separate sections. This segmentation allows the sealing element to be assembled more easily (the sections can be installed separately or as flexible segments) and accommodates thermal expansion (the sections can move independently relative to each other). Despite the segmentation, the sealing effectiveness is maintained through the configuration of the sealing surfaces.

Inventive Principle:

Principle #1Segmentation

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 proposed solution effectively reduces or eliminates leakage flows through the bearing opening, maintaining a high mass flow within the engine core while allowing for easy assembly and temperature-induced expansion of the sealing element.

Implementation Method 1

A section of a sealing element, on which at least one sealing ridge extending radially in relation to the longitudinal axis is formed and/or which has a nonlinear slot passing longitudinally through the section, is provided within the bearing opening

Methodology Applied

Scientific EffectLabyrinth seal:

Implementation Method 2

particularly for easier assembly and to enable temperature-induced expansion of the sealing element, it is possible, along the circumferential direction and in the radial direction, for the sealing element to have a slot passing longitudinally through the sealing element section provided within the bearing opening

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS11187108B2Guide vane assembly with sealing element

Publication Date: 2021.11.30 ROLLS ROYCE DEUT LTD & CO KG

AI summary

The proposed solution relates to a stator vane assembly for an engine, having at least one stator vane of a stator vane row and a casing for the at least one stator vane row, wherein the at least one stator vane is mounted adjustably on the casing by means of a bearing journal, which is rotatably mounted in a bearing opening in the casing and passes through this bearing opening along a longitudinal axis.A section of a sealing element, on which at least one sealing ridge extending radially in relation to the longitudinal axis is formed and/or which has a nonlinear slot passing longitudinally through the section, is provided within the bearing opening.