CMC Mid-Turbine Frame with Spring Biased Tie-Rods
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Solution Overview
Problem
Current mid-turbine frames in gas turbine engines face challenges in withstanding high thermal and pressure loads, leading to potential delamination and leakage issues due to thermal expansion and axial deflection, which existing technologies have not adequately addressed.
Innovation Solution
A mid-turbine frame constructed using Ceramic Matrix Composite (CMC) materials with a ring-strut-ring structure and spring biased tie-rod assemblies that apply compressive force to maintain the frame in a state of compression, reducing thermal expansion effects and minimizing stress risers, thereby enhancing structural integrity and leak-proofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials and structures are used in the mid-turbine frame, then manufacturing simplicity is maintained, but the frame cannot adequately resist thermal and pressure loads leading to delamination and leakage
Solution Approach 1:
The patent applies composite materials by constructing the mid-turbine frame using Ceramic Matrix Composite (CMC) materials with a ring-strut-ring structure. This composite structure provides enhanced resistance to thermal and pressure loads while maintaining structural integrity, directly resolving the contradiction between reliability and structural complexity.
Solution Approach 2:
The patent segments the mid-turbine frame into distinct functional components: an inner ring, outer ring, and strut elements. This segmentation allows each component to be optimized for specific functions (thermal resistance, pressure containment, structural support) while working together to solve the overall reliability issue.
2Stability of the object's composition
If the mid-turbine frame is designed to resist thermal expansion, then structural stability is improved, but axial deflection and delamination risks increase under high thermal loads
Solution Approach 1:
The patent changes the material parameters by using CMC materials with specific thermal expansion characteristics that match the operational environment. This parameter change allows the frame to resist thermal expansion while maintaining strength and preventing delamination under high thermal loads.
Solution Approach 2:
The composite CMC material structure provides both thermal stability and strength resistance simultaneously. The material composition is designed to withstand thermal expansion stresses while maintaining structural integrity, resolving the contradiction between stability and strength.
3Reliability
If spring biased tie-rod assemblies are added to apply compressive force, then leak-proofing is improved, but device complexity increases
Solution Approach 1:
The spring biased tie-rod assemblies are designed to automatically maintain compressive force on the frame elements without requiring external control systems. The springs self-regulate to maintain the necessary compressive force for leak-proofing, achieving reliability through self-service mechanisms.
Solution Approach 2:
The compressive force from the spring biased tie-rod assemblies is applied in advance to counteract potential thermal expansion and pressure-induced separation. This preliminary anti-action prevents leakage before it occurs, improving reliability while adding controlled complexity.
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 CMC mid-turbine frame effectively resists thermal and pressure loads, reducing axial deflection and delamination risks, ensuring a stable and leak-proof structure that maintains structural integrity under varying operational conditions.
Implementation Method 1
spring biased tie-rod assemblies that apply compressive force to maintain the frame in a state of compression
Implementation Method 2
reducing thermal expansion effects
Implementation Method 3
Ceramic Matrix Composite (CMC) materials with a ring-strut-ring structure
Implementation Method 4
resists thermal and pressure loads
Data Source
Figure 1
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AI summary
A static structure of a gas turbine engine (20) includes a multiple of airfoil sections (90) between an outer ring (94) and an inner ring (92). A spring biased tie-rod assembly (80) is mounted through at least one of the multiple of airfoil sections (90).