Dual-Pitch Nut Locking Assembly to Prevent Bolt Loosening
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Solution Overview
Problem
Existing arrangements for securing a nut on a threaded bolt fail to effectively prevent the nut from coming loose, despite attempts to increase friction between the nut and bolt threads.
Innovation Solution
The implementation of a nut-locking element with a threaded portion that engages a second threaded portion on the bolt, featuring a smaller pitch than the primary threaded portion, combined with a friction portion to restrain the nut from rotating relative to the nut-locking element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If friction between nut and bolt threads is increased, then the nut is prevented from loosening, but the device complexity increases
Solution Approach 1:
The nut-locking element is nested within the nut structure, with the locking element fitting inside the nut's internal geometry. The friction portion of the locking element contacts the nut's internal surface, creating a nested configuration that prevents loosening without adding external complexity to the assembly.
Solution Approach 2:
The nut-locking element combines multiple functions into a single component: it engages with the bolt threads for positioning, provides friction contact with the nut to prevent rotation, and maintains the locking function through integrated design. This merging eliminates the need for separate locking mechanisms.
2Reliability
If a nut-locking element is added to prevent loosening, then the nut security is improved, but the ease of operation deteriorates
Solution Approach 1:
The nut-locking element is designed to be installed and removed using the same tool and procedure as the nut itself. The locking element engages automatically with the bolt threads when the nut is screwed on, and releases automatically when the nut is unscrewed, eliminating the need for additional manual operations or specialized tools.
3Reliability
If the second threaded portion has a smaller pitch than the first threaded portion, then the nut is pressed against the nut-locking element to prevent loosening, but the manufacturing precision requirements increase
Solution Approach 1:
The invention changes the thread pitch parameter of the second threaded portion relative to the first threaded portion. The smaller pitch of the second portion creates a mechanical advantage that generates axial force pressing the nut against the locking element, transforming a geometric parameter change into a functional locking mechanism.
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
This solution ensures that the nut is pressed against the nut-locking element, preventing it from loosening, even when attempting to screw the nut outward, thereby maintaining a secure connection between the nut and the bolt.
Implementation Method 1
the nut-locking element being provided with a friction portion arranged to rest supportingly against a corresponding friction portion on the nut
Implementation Method 2
The different pitches result in the fact that if an attempt is made to screw the nut outwards, it thereby trying to pull the nut-locking element along in the rotation, the nut will have a greater axial movement than the nut-locking element. The nut is thereby pressed against the nut-locking element
Data Source
AI summary
An arrangement is for securing a nut on a threaded bolt comprising a bolt shaft projecting from a bolt head and being provided, in an opposite end portion, with a first threaded portion arranged to engage with an internal threaded portion of the nut. The nut and the bolt head are arranged to abut against adjacent elements. A nut-locking element is provided with a threaded portion arranged to engage with a second threaded portion of the threaded bolt. The second threaded portion is arranged externally on a stepped end portion of the threaded bolt and is concentric with and having a smaller pitch than the first threaded portion. The nut-locking element is provided with a friction portion arranged to rest supportingly against a corresponding friction portion on the nut.