Hybrid Piston Seal Ring Structure for Lower Contact Stress Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piston seal rings in gas turbine engines experience severe wear mechanisms such as adhesive galling, impact wear, and abrasive fretting due to high rotation rates, leading to undesirable wear and damage at the interface with rotor borefoot surfaces.
Innovation Solution
The development of a hybrid piston seal ring comprising a lightweight core, typically made of titanium alloys or carbon-carbon composites, and a shell made of nickel or cobalt alloys, with optional solid lubricant coatings, to reduce contact stress and wear, using manufacturing techniques like additive manufacturing and spark plasma sintering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional heavy seal ring materials are used, then sealing reliability is maintained, but contact stress on rotor borefoot surfaces increases causing severe wear
Solution Approach 1:
The patent applies composite materials by creating a hybrid seal ring structure consisting of a titanium alloy core (providing lightweight properties) combined with a nickel or cobalt alloy shell (providing wear resistance). This composite structure reduces the overall density and contact stress on rotor surfaces while maintaining the sealing reliability through the hard, wear-resistant outer shell that directly contacts the rotor borefoot.
Solution Approach 2:
The patent implements local quality by applying different materials to different regions of the seal ring. The core uses lightweight titanium alloy to reduce overall mass and contact stress, while the outer shell uses hard nickel or cobalt alloy to provide localized wear resistance at the contact interface with the rotor. This spatial differentiation of material properties optimizes both weight reduction and wear protection.
2Object-affected harmful factors
If lightweight materials are used for the seal ring, then contact stress is reduced, but wear resistance may be compromised
Solution Approach 1:
The patent resolves this contradiction by using composite materials where the titanium alloy core provides lightweight properties to reduce contact stress, while the nickel or cobalt alloy shell provides the necessary wear resistance. The composite structure allows both lightweight and wear-resistant properties to coexist in different parts of the same component.
Solution Approach 2:
The patent applies local quality by concentrating wear-resistant material (nickel or cobalt alloy shell) only in the regions that require it (the outer contact surface), while using lightweight material (titanium alloy core) in the interior regions where weight reduction is beneficial but wear resistance is not critical.
3Object-affected harmful factors
If hybrid composite structures are implemented, then weight and wear resistance are optimized, but manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the seal ring into two distinct segments: an inner core made of titanium alloy and an outer shell made of nickel or cobalt alloy. This segmentation allows each material to be optimized for its specific function and enables manufacturing through sequential processes (forming the core first, then adding the shell), which simplifies the overall manufacturing complexity compared to creating a fully integrated complex structure.
Data Source
Figure 1~3
Figure 4~6
Figure 7
AI summary
A piston seal ring (22) for sealing between an inner and an outer radial component (12, 14) includes a core having a shell, wherein the core includes a material selected from the group consisting of titanium alloy, titanium-based metal matrix, carbon-carbon composite, electro-graphitic carbon, ceramic matrix composite and combinations thereof, and wherein the shell includes a material selected from the group consisting of nickel alloy, cobalt alloy and combinations thereof.