THSA Lower Attachment with Adjustable Sheet Plate Failure Indication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing lower attachment systems for trimmable horizontal stabiliser actuators have complex and expensive sheet plates that require precise fitting and interfere with failure detection, making them time-consuming and costly to manufacture and install, while also not providing a clear indication of primary load path failure.
Innovation Solution
A lower attachment system with an adjustable sheet plate that uses an adjustment mechanism to set the spacing between mounting points, which breaks upon primary load path failure, allowing the secondary load path to be loaded and indicating failure through physical change, thereby simplifying installation and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional fixed sheet plate is used in the lower attachment system, then the secondary load path can be maintained, but the sheet plate becomes complex and expensive to manufacture, requires precise fitting, and interferes with failure detection
Solution Approach 1:
The sheet plate is divided into two separate components: a fixed mounting bracket attached to the actuator body and a separate adjustable positioning plate attached to the stabilizer. This segmentation simplifies each individual component while maintaining the overall function of the lower attachment system.
Solution Approach 2:
The positioning plate is made adjustable rather than fixed, allowing it to be positioned at different locations along the stabilizer arm. This dynamic adjustment capability simplifies the manufacturing process and eliminates the need for complex precise fitting while still maintaining reliable load path engagement.
2Reliability
If a traditional fixed sheet plate is used in the lower attachment system, then the secondary load path can be maintained, but it becomes time-consuming and costly to manufacture and install
Solution Approach 1:
By segmenting the sheet plate into separate mounting bracket and positioning plate components, each can be manufactured independently using simpler processes, reducing manufacturing time and cost. The separate components can also be prepared in advance and assembled quickly during installation.
Solution Approach 2:
The adjustable positioning plate allows for quick adaptation to different installation requirements without requiring custom manufacturing or complex fitting procedures, significantly improving both manufacturing efficiency and installation speed.
3Reliability
If a traditional fixed sheet plate is used in the lower attachment system, then the secondary load path can be maintained, but it does not provide a clear indication of primary load path failure
Solution Approach 1:
The positioning plate is designed with a visual indicator feature that changes its appearance or position when the primary load path fails. This allows maintenance personnel to easily detect failure conditions through simple visual inspection without requiring complex detection equipment.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A lower attachment system for a trimmable horizontal stabiliser actuator comprising: a ballnut 101 for being disposed on a screwshaft of the actuator and forming a part of a primary load path of the lower attachment system; a trunnion 102 connected to the ballnut 101 and forming a part of the primary load path of the lower attachment system; a failsafe plate 150 disposed about the trunnion 102 and forming a part of a secondary load path; a secondary connection 140 connected to the failsafe plate 150 and forming a part of the secondary load path; a sheet plate 120 attached to a first mounting point 144 on the secondary connection 140 and a second mounting point 104 on the ballnut 101; and an adjustment mechanism 122, 125 provided with the sheet plate 120 for adjusting the size or position of the sheet plate 120 to adapt it to fit a distance between the first and second mounting points.