Reversible Blade Platform Seal for Turbine Hot-Gas Blocking
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Solution Overview
Problem
There is a need for improved sealing capability, ease of installation, and longevity for seals used with rotating parts in turbine engines to prevent hot gases from reaching the rotor and maintain rotor strength.
Innovation Solution
A rotatable sealing structure with slots for receiving blades, where the seal extends axially and is canted at an angle between 0° and 20°, featuring parallelogram-shaped ends and asymmetrical design to engage with rotor shelves, blocking hot gases while allowing cooling air to escape, and can be installed in any orientation to ensure proper assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional seal structure is used, then the sealing capability is limited, but the installation complexity and manufacturing tolerances are not improved
Solution Approach 1:
The seal element features an asymmetrical cross-sectional shape with a first side having a different profile than a second side. This asymmetry enables the seal to be installed in any orientation (0°, 90°, 180°, or 270°) while maintaining proper sealing contact with the blade platform, thereby improving sealing capability without increasing installation complexity
Solution Approach 2:
The seal element is designed to perform multiple functions simultaneously: it provides sealing against hot gases, accommodates centrifugal forces during rotation, allows cooling air to escape, and can be installed in any orientation. This multi-functionality improves reliability while simplifying the overall sealing system design
2Strength
If a seal is designed to prevent hot gases from reaching the rotor, then rotor strength is maintained, but the seal may deform under rotational centrifugal forces
Solution Approach 1:
The seal element is designed to dynamically respond to rotational centrifugal forces. The asymmetrical cross-section and specific material properties allow the seal to deform in a controlled manner during rotation, maintaining sealing effectiveness while accommodating the dynamic loads without permanent deformation or failure
Solution Approach 2:
The seal element's physical parameters (such as cross-sectional geometry and material properties) are optimized to change in response to operational conditions. The asymmetrical shape allows different parts of the seal to experience different stress distributions, enabling the seal to maintain its functional integrity under varying centrifugal forces while preventing hot gas leakage
3Duration of action of stationary object
If the seal is made to accommodate rotational forces, then longevity is improved, but the sealing capability may be compromised
Solution Approach 1:
The asymmetrical cross-sectional design allows the seal to accommodate rotational centrifugal forces while maintaining effective sealing contact. The different profiles on opposite sides of the seal enable it to flex and deform appropriately during rotation without compromising the sealing interface, thereby improving longevity without sacrificing sealing capability
Solution Approach 2:
Different regions of the seal element are designed with different properties to fulfill specific functions. The asymmetrical cross-section creates localized variations in stiffness and flexibility, allowing certain areas to accommodate rotational forces while other areas maintain sealing contact, thus improving longevity without compromising sealing capability
4Reliability
If the seal extends axially and is canted at an angle, then it blocks hot gases effectively, but manufacturing precision requirements increase
Solution Approach 1:
The asymmetrical cross-sectional shape with specific angular features enables the seal to be installed in any orientation while maintaining the correct cant angle relative to the blade platform. This design eliminates the need for precise angular alignment during installation, as the asymmetry itself provides the necessary orientation reference, thereby improving sealing capability without increasing manufacturing precision requirements
Solution Approach 2:
Instead of requiring precise angular alignment during installation, the design inverts the approach by making the seal orientation-independent through asymmetry. The seal's asymmetrical features naturally establish the correct angular relationship with the blade platform regardless of installation orientation, eliminating the need for high-precision angular alignment procedures
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 sealing structure effectively prevents hot combustion gases from reaching the rotor, maintaining rotor strength and ensuring reliable operation by blocking leaks and accommodating rotational centrifugal forces without deforming, thus enhancing the longevity and ease of installation of seals.
Implementation Method 1
the seal is arranged in the pocket and configured to engage the blades to seal the gap
Implementation Method 2
accommodating rotational centrifugal forces without deforming
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
A rotatable sealing structure for a gas turbine engine (20) includes a first blade (64) and a second blade (64). A seal (80) is arranged between the blades (64) and has a body (80) that is configured for operative association with the first and second blades (64) in a first orientation and in a second orientation to seal a gap (76) defined between the blades (64).