Seal Groove Cooling Flow for Fire-Resistant Hydraulic Seals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft engine components with elastomer and PTFE seals face challenges in withstanding high temperatures during fire tests without leaking, as existing cooling methods either require excessive cooling flow or impractical rerouting, and additional solutions like shields or thermal blankets add weight and cost.
Innovation Solution
A seal arrangement that routes cooling hydraulic fluid through seal grooves, providing direct cooling to the seals, which reduces their maximum temperature during fire tests by configuring the coolant flow passages to intersect with the seals in a manner that ensures consistent fluid flow around them.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling flow path is routed closer to seals, then seal temperature is reduced, but device complexity increases due to impractical rerouting
Solution Approach 1:
The seal channel is segmented into a first region for seal seating and a second region for coolant flow, separated by a step feature. This segmentation allows the seal to be positioned in a cooler zone while the coolant flows in an adjacent zone, directly addressing the seal temperature issue without requiring complex rerouting of the cooling flow path.
Solution Approach 2:
The invention introduces a radial dimension to the cooling strategy by creating a step feature that establishes different radial levels within the seal channel. The first region at one radial level houses the seal while the second region at a different radial level carries the coolant flow, enabling direct cooling without increasing axial or circumferential complexity.
2Temperature
If increased cooling flow is used, then seal temperature is reduced, but engine efficiency decreases
Solution Approach 1:
The cooling strategy is localized to only where it is needed - the second region of the seal channel where coolant flow directly contacts or closely approaches the seal. This localized cooling approach reduces the overall cooling flow requirement compared to cooling the entire structural component, thereby minimizing energy loss while still achieving the goal of keeping seal temperature below leakage threshold.
3Temperature
If shields or thermal blankets are employed, then seal temperature is reduced, but weight and cost increase
Solution Approach 1:
The invention extracts the cooling function from separate thermal protection components (shields or thermal blankets) and integrates it directly into the seal channel structure itself. By incorporating the cooling flow path and seal positioning features within the existing structural component, the need for additional thermal protection components is eliminated, reducing weight while maintaining the temperature control function.
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 approach effectively keeps the seals below the leakage temperature for extended periods, meeting fire test standards without compromising engine efficiency or adding weight, as demonstrated by a 23% reduction in seal temperature during fireproof tests compared to conventional cooling methods.
Implementation Method 1
cooling flow is routed through the seal grooves that contain the seals, which has been found to significantly reduce the maximum temperature of the seals during a fire test
Implementation Method 2
The first part of the first coolant flow passage is configured to provide hydraulic fluid to the first seal channel such that, at the first point, a first portion of the hydraulic fluid flows in a first direction around the first loop
Data Source
AI summary
Disclosed are seal arrangements in a hydraulic device. The seal arrangement includes a seal channel defining a loop. A seal is seated within the seal channel. A coolant flow passage has a first part intersecting with the seal channel at a first point and a second part intersecting with the seal channel at a second point. The first part of the coolant flow passage is configured to provide hydraulic fluid to the seal channel such that, at the first point, a first portion of the hydraulic fluid flows in a first direction around the loop and a second portion of the hydraulic fluid flows in a second direction opposite to the first direction around the loop. At the second point, the first portion of hydraulic fluid and the second portion of hydraulic fluid are configured to flow into the second part of the coolant flow passage.