CMC Blade Retention Assembly With Diffusion-Bonded Disk Attachment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in effectively coupling ceramic-matrix composite (CMC) blades with metallic disks in gas turbine engines, as existing designs face difficulties in securely attaching these high-temperature components while allowing for efficient assembly and maintenance.
Innovation Solution
The solution involves a blade retention assembly with a clamp block and mount post forming a diffusion joint, where the clamp block defines a stem cavity for the blade stem, and the mount post extends radially from the disk, allowing for secure attachment through a diffusion-brazed bond, enabling secure mounting and potential removal during overhauls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If CMC blades are coupled with metallic disks using conventional attachment methods, then the blades can be secured to the disk, but the attachment creates high stress concentrations and complicates assembly and maintenance
Solution Approach 1:
The attachment system is segmented into distinct functional components: the CMC blade with integrated root, the metallic disk with mount posts, and the retention assembly with clamp blocks. This segmentation allows each component to be optimized independently and simplifies assembly/disassembly during maintenance while maintaining strong attachment through the retention mechanism
Solution Approach 2:
The invention uses composite material architecture where CMC blades are attached to metallic disks through a retention assembly that interfaces with both material types. The mount posts and clamp blocks are designed to accommodate the different mechanical properties of CMC and metal, reducing stress concentrations at the interface while maintaining secure attachment
2Strength
If conventional attachment methods are used for CMC blades, then the blades can be secured to the disk, but stress distribution is uneven and blade integrity is compromised
Solution Approach 1:
The retention assembly implements local quality by providing enhanced support and stress distribution specifically at the blade-root attachment zone. The clamp blocks and mount posts are designed to distribute loads evenly across the CMC blade root, preventing stress concentrations that would compromise blade integrity while allowing the rest of the blade to maintain its optimized CMC structure
3Temperature
If CMC blades are attached to metallic disks, then high-temperature performance is achieved, but maintenance and blade replacement become difficult
Solution Approach 1:
The retention assembly provides a dynamic attachment system that allows blades to be securely fixed during operation but easily removed during maintenance. The clamp blocks can be positioned to secure blades under centrifugal load, yet can be quickly released for blade replacement, enabling the system to transition between fixed and accessible states without compromising high-temperature performance
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 provides a strong, low-weight attachment that reduces stress on the blades, aligns mechanical stresses with the CMC architecture, and allows for efficient assembly and maintenance, enhancing the operational efficiency and durability of the turbine components.
Implementation Method 1
The clamp block may be arranged about the blade stem and joined with the at least one mount post of the disk by a diffusion joint formed between the at least one mount post and the clamp block
Data Source
AI summary
A turbine blade is secured with a turbine disk by a retention assembly. The turbine blade includes a blade stem and the disk includes at least one mount post for mounting of the turbine blade. The retention assembly is secured with the disk by forming a diffusion joint with the disk.