Double Bellows Valve for Fail-Open Turbine Cooling Airflow

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Valves in gas turbine engines can fail in undesirable positions, leading to undercooling or other undesirable effects in the turbine due to the inability to control cooling air effectively.

Innovation Solution

A double bellows valve design that ensures the valve remains in an open position by default, even in the event of failure, using a first and second bellows system to maintain airflow to the turbine, preventing failure in the closed position and ensuring continuous cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single bellows valve is used to control cooling air flow, then the device complexity is reduced, but the reliability deteriorates because the valve may fail in either open or closed position

Engineering Contradiction:

Improvevalve position reliabilityVSAvoidbellows valve structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The single bellows valve is divided into two separate bellows: a first bellows and a second bellows. Each bellows is responsible for controlling the valve stem position independently. This segmentation ensures that even if one bellows fails, the other can maintain the valve in the desired open position, thereby improving reliability without requiring a completely complex redundant system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The dual bellows configuration provides a built-in fail-safe mechanism. The second bellows acts as a backup that can compensate for potential failures in the first bellows. This beforehand cushioning approach ensures that the valve will not fail in an undesirable closed position, as the second bellows can maintain airflow and keep the valve open even when the first bellows fails.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Object-affected harmful factors

If the valve is designed to fail closed for safety, then harmful factors are reduced, but the productivity deteriorates due to turbine undercooling

Engineering Contradiction:

Improveturbine overheating riskVSAvoidturbine cooling efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

Instead of designing the valve to fail closed (traditional safety approach), this invention inverts the fail-safe logic by designing the dual bellows system to ensure the valve fails open. The second bellows acts as a backup that maintains the open position even when the first bellows fails, ensuring continuous cooling airflow to the turbine and preventing productivity loss from undercooling.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The potential harm of valve failure is converted into a benefit through the dual bellows design. What would traditionally be a harmful failure mode (valve closing) is transformed into a beneficial fail-open behavior where the second bellows ensures continuous airflow, turning a potential safety issue into a reliability advantage that maintains both safety and productivity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If a redundant bellows system is implemented to prevent failure, then reliability is improved, but the device complexity increases

Engineering Contradiction:

Improvecooling air supply reliabilityVSAvoidactuator system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The redundant actuator system is segmented into two independent but cooperative bellows. Each bellows is a simple, well-understood component that can be manufactured and maintained with existing technology. This segmentation allows the system to achieve high reliability through redundancy while keeping individual components simple and the overall architecture manageable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The two bellows are merged into a single integrated actuator assembly that works together to control the valve stem. This merging approach consolidates the redundant components into a unified structure, reducing the overall system complexity compared to having completely separate backup systems. The bellows share common mounting and control mechanisms, simplifying installation and maintenance.

Inventive Principle:

Principle #5Merging (Combining)

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 double bellows valve design guarantees continuous airflow to the turbine, preventing undercooling and ensuring reliable operation by maintaining the valve in an open position even if components fail, thus enhancing the engine's performance and safety.

Implementation Method 1

The actuator may include a first bellows coupled with the valve stem to define a working fluid chamber and a second bellows coupled with the valve stem and the valve body to define a supply fluid chamber

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12607266B2Double bellows valve for preventing undesired valve failure positions

Publication Date: 2026.04.21 ROLLS ROYCE NORTH AMERICAN TECHNOLOGIES INC

AI summary

A gas turbine engine includes a combustor and a valve coupled to the combustor. The valve includes a valve body, a valve stem, and an actuator. The valve body is formed to define an air chamber. The valve stem is movable between a closed position and an open position. The actuator is configured to move selectively the valve stem between the closed position and the open position.