Locking Threaded Fastener Assembly for Vibration Loosening Resistance
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Solution Overview
Problem
Threaded fasteners often loosen over time, especially under vibrations or varying loads, and existing locking solutions like nylon lock nuts, thread compounds, and wire locks have drawbacks such as non-reusability, improper application risks, and installation difficulties.
Innovation Solution
A locking fastener assembly comprising a fastener with a threaded portion and a head having a locking washer recess, where a locking washer with a locking tab and stop is disposed within the recess, and a locking member interfaces with the stop to lock the fastener against loosening rotation, providing secure torqueing and loosening resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional locking solutions (nylon lock nuts, thread compounds, wire locks) are used to prevent fastener loosening, then reliability is improved, but ease of operation deteriorates due to non-reusability, improper application risks, and installation difficulties
Solution Approach 1:
The locking mechanism is divided into separate functional components: a locking washer with locking tabs and stops, and a locking member with engagement features. This segmentation allows the locking function to be independently activated during tightening while maintaining ease of removal by simply backing off the fastener, thus improving both reliability and ease of operation
Solution Approach 2:
The locking washer is pre-configured with locking tabs and stops positioned to engage with the locking member before the fastening operation begins. This preliminary arrangement ensures that as the fastener is tightened, the locking mechanism automatically engages without requiring additional steps or tools, improving ease of operation while ensuring reliable locking
2Reliability
If locking mechanisms are added to prevent fastener loosening, then reliability is improved, but device complexity increases
Solution Approach 1:
The locking washer combines multiple locking functions into a single component: it integrates locking tabs for engagement, stops for positioning, and a body that interfaces with both the fastener and the locking member. This merging reduces the number of separate parts needed while maintaining reliable locking, thus improving reliability without proportionally increasing complexity
Solution Approach 2:
The locking washer serves multiple functions simultaneously: it provides a bearing surface, contains the locking tabs and stops, interfaces with the locking member, and prevents fastener loosening. This multi-functionality reduces the need for additional specialized components, thereby improving reliability while controlling overall device complexity
Data Source
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AI summary
A locking fastener assembly comprising a fastener having a threaded portion, and a head having a first end and a second end axially spaced from the first end, the second end comprising a fastening surface and a locking washer recess. The locking fastener assembly further comprises a locking washer disposed at least partially within the locking washer recess, the locking washer comprising a locking tab extending in a first direction and a stop biased in a second direction opposing the first direction, wherein the locking tab is operable to lock rotation of the locking washer relative to an item being secured upon a torqueing rotation and a loosening rotation of the fastener. A locking member is supported by the fastener, and operable to interface with the stop of the locking washer upon the loosening rotation of the fastener to lock the fastener relative to the item being secured.