Aircraft Blade Plug for Pressure Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft blades experience increased stresses due to differential pressure between trapped ambient air in the blade cavity and altitude air, which is not addressed by existing sealing methods during manufacturing.
Innovation Solution
A blade plug system with a first body and a second body, a plug cap, and fasteners that allow for fluid communication through the blade plug, enabling the creation of a vacuum or pressure adjustment within the blade cavity during manufacturing, thereby minimizing differential pressure stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the blade cavity is sealed during manufacturing to prevent hub oil migration, then sealing reliability is improved, but differential pressure stresses increase during operation
Solution Approach 1:
The patent applies preliminary action by creating a vacuum within the blade cavity during the manufacturing process, before the blade is installed in the aircraft. This advance preparation equalizes the pressure conditions, preventing the harmful differential pressure stresses that would otherwise occur during flight operations at altitude.
Solution Approach 2:
The patent changes the pressure parameter within the blade cavity by establishing a vacuum condition during manufacturing. This parameter change from ambient pressure to vacuum pressure resolves the contradiction by ensuring that when the blade operates at altitude, there is no significant pressure differential between the cavity interior and exterior environments.
2Reliability
If a fixed seal is used to prevent fluid migration, then sealing effectiveness is improved, but adaptability to pressure changes deteriorates
Solution Approach 1:
The patent applies dynamics by making the blade plug removable and adjustable rather than permanently fixed. The plug can be removed during manufacturing to establish a vacuum, then reinstalled to provide sealing while allowing for future removal if pressure equalization is needed. This dynamic capability provides adaptability to changing pressure conditions throughout the blade's service life.
Solution Approach 2:
The blade plug serves multiple functions: it seals the cavity during normal operation to prevent oil migration, but can be removed to allow pressure equalization or vacuum establishment. This multi-functionality resolves the contradiction between maintaining effective sealing and adapting to pressure changes.
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 solution effectively reduces or eliminates stresses on the blade by allowing fluid communication to or from the blade cavity, enabling the formation of a vacuum or pressure adjustment, thus mitigating the effects of differential pressure during operation.
Implementation Method 1
a differential pressure may exist between the air locked within the blade cavity and the ambient air at altitude
Implementation Method 2
forming a vacuum in the blade cavity during manufacture of the blade
Data Source
AI summary
A blade plug for an aircraft blade is provided. The blade plug includes a first body having a boss extending therefrom and an aperture passing through the boss, the first body configured to sealingly engage with an opening of a blade, a plug cap configured to releasably engage with the boss and move between a first position and a second position, and a passage passing through the first body configured to allow fluid communication through the first body. When the plug cap is in the first position, fluid may not pass through the passage and, when the plug cap is in the second position, fluid may pass through the passage, and the first body has an outer diameter of 4.15 inches (105.37 mm).