Threaded Fastener Lock with Extending Tabs for Gas Turbine Retention
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Solution Overview
Problem
In gas turbine engines and similar applications, blind fasteners often cannot be accessed or removed due to obstructing structures, hindering further disassembly, and existing fastener locks are either expensive or prone to causing foreign object damage.
Innovation Solution
A fastener lock made from 17-7PH stainless steel with a diameter that increases when relaxed, featuring extending tabs and a non-parallel axial plane, is designed to be retained within a lock recess, preventing the fastener from falling back and minimizing thread interference, while being securely engaged with the threaded fastener.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a blind fastener is used in obstructed access applications, then the fastener can be installed and secured, but the fastener cannot be removed or accessed for further disassembly
Solution Approach 1:
The fastener system is divided into separate functional components: the fastener itself and a retention member. The retention member remains in the recess to prevent loss while allowing the fastener to be removed and reused, enabling both secure installation and easy removal.
Solution Approach 2:
A retention member acts as an intermediary component between the recess and the fastener. It provides the removal function by preventing fastener loss without interfering with the fastener's primary fastening function, resolving the contradiction between secure installation and easy removal.
2Reliability
If a traditional fastener lock is used to prevent fastener loss, then the fastener can be retained, but the lock may cause foreign object damage or require expensive materials
Solution Approach 1:
The harmful potential is extracted by designing the retention member with features that prevent it from becoming a foreign object hazard. The non-parallel axial plane and extending tabs ensure the retention member stays securely in place without protruding or loosening, eliminating the risk of foreign object damage while maintaining fastener retention.
Solution Approach 2:
The retention member is designed as a simple, inexpensive component made from standard stainless steel rather than expensive specialized materials. It performs its retention function reliably without requiring costly materials, making the system both safe and economical.
3Reliability
If the fastener lock diameter is increased to improve retention, then the fastener is held more securely, but the lock interferes with thread engagement
Solution Approach 1:
The retention member employs asymmetric geometry with a non-parallel axial plane and extending tabs positioned at specific angles. This asymmetric design allows the retention member to engage securely with the fastener threads while maintaining sufficient clearance to prevent interference with proper thread engagement, resolving the contradiction between retention security and thread compatibility.
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 retains the fastener within the upper recess, allowing for axial removal of components without the risk of foreign object damage and reducing the need for expensive materials, enhancing disassembly capabilities while ensuring secure retention.
Implementation Method 1
a diameter of the fastener lock in a relaxed state is greater than a diameter of the upper recess
Data Source
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AI summary
The present disclosure relates generally to a fastener lock (120) for engaging a threaded fastener. The fastener lock defines a discontinuous circular opening therethrough with at least one extending tab (132) extending into the discontinuous circular opening. When a threaded fastener is disposed in the discontinuous circular opening, the at least one extending tab (132) engages the threads of the threaded fastener.