Floating Support Ring for Adjustable Blade Outer Air Seal
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Solution Overview
Problem
Existing blade outer air seal systems in gas turbine engines face challenges in quickly and precisely adjusting the radial position of shrouds to minimize gas leakage, as they often require indirect movement of the case or support structure, limiting rapid and precise control.
Innovation Solution
An adjustable blade outer air seal apparatus with a support ring non-rigidly mounted on spring connections, allowing the support ring to float and enabling direct radial adjustment of blade outer air seal segments, utilizing a threaded shaft and actuation arm for fine control, and an adjustable spacer with stacked washers for initial positioning, along with anti-rotation features to prevent misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the shroud is indirectly moved by moving the case or support structure, then the structural integrity is maintained, but the ability to move the shroud quickly and precisely is inhibited
Solution Approach 1:
The air seal system is segmented into a stationary support ring and a movable air seal segment. This allows the air seal segment to be adjusted independently without moving the entire case or support structure, enabling quick and precise adjustment while maintaining structural integrity of the stationary components.
Solution Approach 2:
The movable air seal segment is extracted from the stationary support structure. The air seal segment can be radially adjusted relative to the stationary support ring through threaded shafts and actuation arms, allowing independent movement of the sealing function while the support structure remains fixed and structurally sound.
2Reliability
If the air seal segment is radially adjustable relative to the support ring, then the gas leakage control is improved, but the device complexity increases
Solution Approach 1:
The air seal segment is made dynamically adjustable through threaded shafts that can be rotated by actuation arms. This allows the radial position of the air seal segment to be changed as needed, improving gas leakage control. The dynamic adjustment capability is achieved through simple threaded mechanisms rather than complex systems.
Solution Approach 2:
The radial position parameter of the air seal segment can be changed by rotating the threaded shafts. This parameter change allows precise control of the clearance between the air seal and blade tips, optimizing gas leakage control. The adjustment is achieved through straightforward threaded motion conversion.
3Adaptability or versatility
If the support ring is non-rigidly mounted on spring connections, then the radial floating capability is enabled, but the positioning stability is reduced
Solution Approach 1:
The support ring is mounted with spring connections that allow radial floating movement, enabling the system to adapt to thermal expansion and operational variations. The springs provide dynamic compliance while maintaining stable positioning through their elastic properties, balancing adaptability with stability.
4Measurement precision
If the threaded shaft and actuation arm mechanism is used, then the fine control capability is improved, but the manufacturing complexity increases
Solution Approach 1:
Complex electronic or hydraulic control systems are replaced with a simple mechanical threaded shaft and actuation arm mechanism. This mechanical system provides fine control capability through the inherent precision of threaded motion, while being easier to manufacture and maintain compared to more complex control systems.
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
Enables rapid and precise adjustment of blade outer air seal positions in response to flight conditions or temperature changes, reducing rub and extending seal lifetime by allowing direct mechanical movement, thereby improving gas leakage control and operational efficiency.
Implementation Method 1
a support ring non-rigidly mounted to the case on spring connections radially inwards of the case, whereby the support ring radially floats with respect to the case
Data Source
AI summary
An adjustable blade outer air seal apparatus includes a case that extends circumferentially around an axis, a support ring non-rigidly mounted to the case on spring connections radially inwards of the case, whereby the support ring floats with respect to the case, and at least one blade outer air seal segment that is radially adjustable relative to the support ring.