Rotor Seal Flexible Brush Elements Thermal Expansion

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Solution Overview

Problem

In rotary machines, such as gas turbine engines, the thermal expansion mismatch between the rotor and stator often leads to fluid leakage due to the spacing required to accommodate thermal growth, which existing seals fail to adequately address across varying operational temperatures.

Innovation Solution

A seal comprising a first flexible element and a second flexible element, where the first flexible element forms a radial interface and the second flexible element forms an axial interface with the stator, utilizing brush bristles to create a curtain effect and accommodate thermal expansion differences, thereby reducing fluid leakage in both hot and cool states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the rotor and stator are spaced apart to accommodate thermal growth, then the rotor can expand freely with temperature changes, but fluid leakage occurs between the rotor and stator

Engineering Contradiction:

Improvethermal expansion accommodationVSAvoidfluid leakage

Core Design Contradiction:

TemperatureVSLoss of substance

Solution Approach 1:

The patent employs flexible elements comprising brush bristles that can deform and adapt to the changing gap between rotor and stator during thermal expansion. These flexible elements maintain sealing contact while accommodating the relative movement caused by temperature changes, preventing fluid leakage without constraining thermal growth.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing solution transitions from a static seal to a dynamic one where the flexible elements can move and adjust their position. The brush bristles are designed to flex and conform to the varying gap dimensions as the rotor expands or contracts with temperature changes, maintaining effective sealing under dynamic conditions.

Inventive Principle:

Principle #15Dynamics

2Loss of substance

If a seal is provided to prevent fluid leakage, then fluid sealing is improved, but the seal must accommodate varying thermal expansion differences between rotor and stator

Engineering Contradiction:

Improvefluid leakage preventionVSAvoidthermal expansion adaptation

Core Design Contradiction:

Loss of substanceVSAdaptability or versatility

Solution Approach 1:

The flexible elements with brush bristles provide a compliant sealing interface that can adapt to thermal expansion variations. The bristles flex and adjust their configuration based on the gap changes caused by differential thermal expansion between rotor and stator, maintaining sealing effectiveness across a range of operating temperatures.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The seal design allows for changes in the physical parameters of the flexible elements, particularly their deformation and positioning, in response to temperature changes. This enables the seal to maintain its function despite variations in the rotor-stator gap caused by thermal expansion differences.

Inventive Principle:

Principle #35Parameter changes

3Loss of substance

If existing seals are used, then some fluid sealing is achieved, but they fail to adequately address leakage across varying operational temperatures

Engineering Contradiction:

Improvefluid leakage reductionVSAvoidsealing performance consistency

Core Design Contradiction:

Loss of substanceVSReliability

Solution Approach 1:

The flexible brush element seal provides consistent sealing performance across varying temperatures by maintaining contact through its flexibility. Unlike rigid seals that may fail when gap dimensions change, the brush bristles continuously adapt to the changing geometry, ensuring reliable leakage prevention in both hot and cool operating states.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The dynamic nature of the flexible seal allows it to respond to temperature-induced dimensional changes in real-time, maintaining sealing effectiveness. This dynamic adaptation ensures consistent reliability across the full operational temperature range, overcoming the limitations of static seal designs.

Inventive Principle:

Principle #15Dynamics

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 dual flexible element seal effectively minimizes fluid leakage by adapting to thermal expansion changes, ensuring a consistent sealing performance across temperature variations, thereby enhancing the operational efficiency and reliability of rotary machines.

Implementation Method 1

utilizing brush bristles to create a curtain effect

Methodology Applied

Scientific EffectCurtain effect:

Implementation Method 2

utilizing brush bristles to create a curtain effect

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 3

accommodate thermal expansion differences

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

A seal comprising a first flexible element and a second flexible element

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12000296B2Seal for a rotor

Publication Date: 2024.06.04 GENERAL ELECTRIC CO

AI summary

A seal for a rotor is provided. The rotor defines an axial direction, a circumferential direction, and a radial direction. The seal includes a first flexible element coupled to the rotor. The first flexible element extends in a first direction that is within forty five degrees of the axial direction.