Keystoning Ceramic Blade Track Segments
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Solution Overview
Problem
The single-piece construction of blade tracks in gas turbine engines presents manufacturing challenges and gaps between adjacent segments, which can affect the engine's performance and reliability.
Innovation Solution
The use of ceramic matrix composite blade track segments with circumferentially-extending metallic splines that form a tight fit within spline-receiving slots, creating a keystone effect to provide a self-supporting, full hoop assembly that resists movement and maintains contact across operating temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-piece construction of blade track is used, then manufacturing simplicity is improved, but gaps between adjacent segments cannot be avoided and structural integrity deteriorates
Solution Approach 1:
The blade track is divided into multiple segments that can be manufactured separately and then assembled together using keystone segments and splines. This segmentation allows each piece to be manufactured independently while maintaining overall structural integrity through the keystone configuration that prevents gap formation between segments.
2Adaptability or versatility
If multiple segments are used to construct blade track, then manufacturing flexibility is improved, but gaps between adjacent segments occur and reliability worsens
Solution Approach 1:
The keystone segment is designed with an asymmetric geometry where one end has a different configuration than the other, allowing it to wedge tightly between adjacent segments. This asymmetric design creates a self-locking mechanism that prevents gap formation while maintaining manufacturing flexibility through modular assembly.
3Object-affected harmful factors
If ceramic matrix composite materials are used, then heat shielding capability is improved, but manufacturing complexity increases
Solution Approach 1:
The ceramic matrix composite blade track is segmented into multiple pieces that can be manufactured using additive manufacturing techniques. This segmentation reduces the complexity of manufacturing large monolithic ceramic components while maintaining the superior heat shielding properties of the ceramic material throughout the structure.
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
This configuration enhances the structural integrity and heat shielding of the blade tracks, ensuring uninterrupted support and reduced manufacturing complexities while withstanding high temperatures, thus improving the engine's efficiency and reliability.
Implementation Method 1
The circumferentially-extending spline may be tight fit in the spline-receiving slot of the second blade track segment to couple the first blade track segment to the second blade track segment and resist circumferential movement
Implementation Method 2
A circumferentially-extending spline that extends from the first blade track segment into the spline-receiving slot of the second blade track segment
Implementation Method 3
A circumferential end of the runner included in the second blade track segment may contact a circumferential end of the runner included in the first blade track segment so that the second blade track segment provides a keystone for circumferentially supporting the first blade track segment
Implementation Method 4
The first blade track segment may be shaped to include a runner that extends partway around a central axis... comprising ceramic matrix composite materials
Implementation Method 5
across the range of operating temperatures of the blade track
Data Source
AI summary
A blade track used in gas turbine engines to define an outer boundary of the primary gas path through a turbine section of a gas turbine engine is disclosed. The blade track includes segments comprising ceramic matrix composite materials that are assembled such that the blade track segments keystone against one another to provide a self-supporting full hoop assembly. Circumferentially-extending splines may be used to couple adjacent segments to one. Also disclosed are other heat shielding assemblies used in gas turbine engines that share features with the illustratively disclosed blade track.