Nut and Washer Assembly for Aircraft Landing Gear
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Solution Overview
Problem
Conventional nut and washer assemblies in aircraft landing gears are prone to improper installation, leading to safety issues and costly repairs due to the washer being easily misplaced during wheel servicing, as it can get stuck to the old wheel due to grease or dirt buildup, making it difficult to detect visually or by feel.
Innovation Solution
A nut and washer assembly where the washer is integrated within a mechanical sleeve housing that is swaged to capture and lock the washer, allowing rotational movement while preventing separation from the nut, ensuring the washer and nut are installed and removed as a single unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the washer is used as a separate component during wheel installation, then the washer can be easily misplaced or lost during servicing, but integrating the washer with the nut increases the complexity of the fastener assembly
Solution Approach 1:
The patent combines the washer and nut into a single integrated fastener assembly. The washer is positioned within the nut structure, and the swaged housing captures both components together, ensuring they are installed and removed as one unit. This merging eliminates the risk of washer omission while maintaining operational simplicity.
Solution Approach 2:
The washer is nested within the nut assembly, specifically positioned inside the swaged housing that forms part of the nut structure. This nesting arrangement allows the washer to be contained within the larger nut component, ensuring they remain associated during handling and installation without requiring separate storage or tracking.
2Reliability
If the washer is integrated within the nut assembly, then the washer cannot be separated from the nut, but this may interfere with the independent function of the washer
Solution Approach 1:
The swaged housing is designed to allow rotational movement of the washer relative to the nut while preventing axial separation. This dynamic capability enables the washer to rotate independently during wheel installation and servicing, maintaining its load-distributing function, while the swaged portions ensure the washer remains contained within the assembly and cannot be lost.
3Ease of operation
If the washer is located between the wheel and nut, then it is difficult to detect visually or by feel whether the washer is present, but making the washer more visible may increase the overall size of the assembly
Solution Approach 1:
The washer and/or housing portions can be configured with contrasting colors or visual features that make the presence of the washer assembly visible during installation. This allows mechanics to easily confirm proper installation without increasing the functional dimensions of the fastener, as the visual indication is achieved through surface characteristics rather than added volume.
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
Prevents washer omission during reassembly, ensuring proper installation and reducing the risk of damage and safety hazards, thereby enhancing aircraft safety and reducing maintenance costs.
Implementation Method 1
the mechanical sleeve housing is fitted (e.g., swage fitted) to capture and lock the washer onto the mechanical sleeve housing
Data Source
AI summary
A nut and washer assembly includes a washer unit that is coupled to a nut. The washer unit includes a housing and a washer that is disposed within a sleeve on an inner surface of the housing such that the washer is inseparable from and axially rotatable with respect to the housing. The housing is attached to the nut such that the washer captured within the housing of the washer unit and the nut operate as a single unit.