Segmented Airfoil Retention Assembly for Turbomachines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing airfoil attachment methods in turbomachines, such as welding or brazing, hinder the repair or replacement of airfoils due to their inability to withstand extreme temperatures and pressures, and do not allow for easy maintenance.
Innovation Solution
A retention assembly comprising multiple segments with mechanical fasteners and sub-collars that securely hold airfoil assemblies in place while allowing for easy disassembly, utilizing nickel components that grow thermally with the engine components and providing a seal to prevent radial movement and facilitate airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding or brazing is used to attach airfoils, then the airfoil attachment strength is improved, but the ease of repair and replacement deteriorates
Solution Approach 1:
The attachment system is divided into separate components: a retention assembly with multiple retention segments that can be independently removed from the airfoil and support structure. This segmentation allows the airfoil to be easily detached and replaced without affecting the support structure, while maintaining strong attachment during operation through the distributed retention segments.
Solution Approach 2:
The retention assembly acts as an intermediary component between the airfoil and the support structure. Instead of directly welding or brazing the airfoil to the support structure, the retention assembly provides a removable mechanical connection that maintains attachment strength while enabling easy repair and replacement by simply removing the retention assembly.
2Ease of repair
If mechanical fasteners are used to secure airfoils, then the ease of repair and replacement is improved, but the attachment reliability under extreme temperatures and pressures deteriorates
Solution Approach 1:
The retention segments and support structure are designed to accommodate thermal expansion and contraction through their geometric relationships and clearance fits. The retention segments can move relative to each other and to the support structure to accommodate thermal growth, maintaining reliable attachment under extreme temperatures while remaining easily removable for repair.
Solution Approach 2:
The attachment system combines different materials with complementary properties: the retention segments and support structure are made from nickel-based alloys that grow thermally with the engine components, providing high-temperature reliability, while the mechanical fastening mechanism provides ease of repair and replacement.
3Ease of repair
If a retention assembly with multiple segments is used, then the ease of repair and replacement is improved, but the device complexity increases
Solution Approach 1:
The retention assembly is segmented into multiple identical or similar retention segments that can be independently removed and replaced. This segmentation simplifies the repair process by allowing replacement of only the worn segments rather than the entire assembly, and the modular design makes the complexity manageable through standardization.
Solution Approach 2:
The retention segments are designed with universal features that allow them to be used in multiple positions and configurations within the same support structure. The segments can accommodate different airfoil sizes and configurations, providing versatility that reduces the need for multiple specialized components and simplifies the overall system.
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 retention assembly effectively secures airfoils, enabling easy repair and replacement while maintaining structural integrity and sealing, and occupies a small area with a large contact load spread, enhancing the operational efficiency and maintenance of turbomachines.
Implementation Method 1
utilizing nickel components that grow thermally with the engine components
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An airfoil retention arrangement includes a retention assembly (54) having a first retention segment (58) and a second retention segment (62). Each of the retention segments (58, 62) is separately moveable to an installed position relative to an airfoil assembly (46) and a support structure (50). The retention segments (58, 62) each have a portion positioned between a lip (94) of the airfoil assembly (46) and a collar (66) of the support structure (50) when the retention segments (58, 62) are in the installed position. The retention assembly (54) is configured to limit radial movement of an airfoil (46) relative to the support structure (50) when in the installed position.