Cowl Hoop Latch Assembly to Reduce Panel Radial Displacement
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Solution Overview
Problem
Conventional cowl panels in propulsion assemblies experience radial movement and deformation during flight, leading to air gaps and erosion, which affect the operation and integrity of the propulsion system.
Innovation Solution
A latch assembly with a pin and pin guide mechanism, including a solenoid coil and spring, is used to secure the cowl panels in a closed position, preventing radial movement and maintaining panel alignment with the nacelle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cowl panels are used without a latch assembly, then the structure is simpler, but radial movement and deformation occur during flight causing air gaps and erosion
Solution Approach 1:
The latch assembly is divided into separate functional components: a latch mechanism with movable latch members, a pin assembly with spring-loaded pins, and a control system. This segmentation allows each component to perform its specific function independently, improving reliability while keeping the overall system manageable in complexity.
Solution Approach 2:
The patent replaces purely mechanical latch systems with an electro-mechanical system that incorporates solenoids and spring-loaded pins. This substitution provides more reliable engagement and disengagement control, preventing radial movement during flight, while the modular design keeps the added complexity acceptable.
2Ease of operation
If the cowl panel is made moveable for access, then maintenance capability is improved, but radial movement during flight causes air gaps and erosion
Solution Approach 1:
The latch assembly is designed to engage the cowl panel in a predetermined closed position before flight, using spring-loaded pins and latch members that automatically secure the panel. This preliminary action ensures the panel is properly positioned and secured against radial movement, preventing air gaps and erosion during flight while still allowing moveability for maintenance when needed.
Solution Approach 2:
The system changes the state parameter of the cowl panel from moveable to securely fixed during flight operation through the engagement of the latch mechanism. The spring-loaded pins transition from retracted to extended positions, and latch members engage to change the panel's radial position parameter, eliminating air gaps and erosion risks while maintaining ease of operation for maintenance when the latch is disengaged.
3Reliability
If multiple latch assemblies are distributed circumferentially, then panel securing is improved, but the number of components increases
Solution Approach 1:
Each latch assembly is designed as a universal, multi-functional unit that combines latch members, spring-loaded pins, and control mechanisms in a single integrated package. This universality allows multiple identical assemblies to be distributed circumferentially around the cowl panel, improving securing effectiveness without proportionally increasing overall system complexity, as each unit performs multiple functions independently.
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 latch assembly effectively reduces radial displacement of cowl panels, minimizing air gaps and erosion, thereby enhancing the operational efficiency and durability of the propulsion system.
Implementation Method 1
The first latch portion may include a frame and a spring. The frame may extend circumferentially about the pin axis and surround the pin. The spring may be positioned between the frame and the pin. The spring may be configured to bias the pin in the extended position.
Implementation Method 2
The first latch portion may include a solenoid coil surrounding the pin. The solenoid coil may be configured to effect translation of the pin along the pin axis from the extended position to the retracted position with the solenoid coil in an energized condition.
Data Source
AI summary
A nacelle for a gas turbine engine includes a fixed nacelle portion, a cowl panel, and a latch assembly. The fixed nacelle portion extends circumferentially about an axial centerline. The cowl panel is axially adjacent the fixed nacelle portion. The cowl panel is moveable relative to the fixed nacelle portion between an open position and a closed position. The latch assembly includes a first latch portion and a second latch portion. The first latch portion is mounted to the cowl panel. The first latch portion includes a pin configured for translation along a pin axis between an extended pin position and a retracted pin position. The second latch portion is mounted to the fixed nacelle portion. The second latch portion includes a pin guide. The pin guide is configured to receive and engage the pin with the pin in the extended position and the cowl panel in the closed position.