Reverse-Thread Nut Locking Assembly for Vibration Resistance
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Solution Overview
Problem
Existing locking devices with reverse-direction threads face difficulties in assembly and locking due to limited angle of rotation, making them difficult to mount and dismantle, and are prone to unlocking under vibrations.
Innovation Solution
The locking device features identical and constant thread pitches for all threads and tappings, with increased radial clearances and standardized ISO triangular profiles, allowing for a wider range of rotation and incorporating a visual marking system and positive locking mechanism with a washer for secure engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different pitches are used between the thread of the assembly 'ring/nut' and the threads of the 'screw/nut' and 'screw/ring' assemblies, then the ring can rotate relative to the nut over a fairly wide angle, but the assembly becomes difficult to mount and lock
Solution Approach 1:
The patent applies parameter changes by using identical and constant thread pitches for all threads and tappings (first, second, and third tappings), which resolves the contradiction between achieving wide rotation angle and ease of assembly. This uniform pitch parameter allows the ring to rotate freely relative to the nut while maintaining simple assembly procedures, eliminating the need for different pitch values that would complicate mounting.
2Adaptability or versatility
If finer or wider pitches are used, then the angle of rotation is increased, but the locking device becomes difficult to mount and lock due to limited rotation angle
Solution Approach 1:
The patent maintains identical and constant thread pitches for all threading elements, which simplifies manufacturing while still achieving the required angle of rotation. This uniform pitch parameter allows for easier manufacturing compared to using finer or wider varying pitches, while the increased radial clearances compensate to enable sufficient rotation freedom.
Solution Approach 2:
The patent introduces radial clearance as an additional dimensional parameter to achieve rotation freedom without relying on pitch variations. By increasing the radial clearances between threading elements, the patent enables angular movement in a different dimensional space, allowing the ring to rotate relative to the nut while maintaining constant pitch values for ease of manufacture.
3Reliability
If the thread flanks are in contact, then the locking device maintains secure engagement, but the device is prone to unlocking under vibrations
Solution Approach 1:
The patent applies preliminary anti-action by designing the locking mechanism to automatically counteract unscrewing forces before they can cause unlocking. The reverse-direction thread of the ring/nut assembly creates opposing wedge forces that push the nut against the screw head, maintaining contact and preventing vibration-induced loosening. This built-in counteracting mechanism ensures stability under vibrational conditions.
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 design enhances the locking device's ability to maintain secure engagement over a wider angle range, simplifies assembly, and provides a visual indication of correct locking, while withstanding high torque without unlocking, exceeding standard torque requirements.
Implementation Method 1
the first, second and third tappings and the first and second threads have an identical and constant thread pitch; and each of the second and third radial clearances is greater than the first radial clearance
Implementation Method 2
the thread flanks 'screw/nut' and 'ring/screw' undergo wedge forces in opposite directions due to the reverse-direction thread of the 'ring/nut' assembly
Implementation Method 3
the second thread is able to cooperate with the second tapping so as to define a second radial clearance; each of the second and third radial clearances is greater than the first radial clearance
Data Source
AI summary
The invention concerns a unit (210) for a locking device, comprising: a nut (212) comprising two coaxial taps in opposite directions; and a ring (213); said ring including a third tap (38); the first (18) and third (38) taps being capable of engaging with a single first thread (22); said ring including a second thread (40) capable of engaging with the second tap (20) of the nut. The unit further comprises a washer (214) configured (274) so as to be inserted around one (212) of the nut and the ring, the washer comprising an elastic engagement means (272) for engaging with the other (213) of the ring and the nut in an installation position of the unit, so as to prevent the ring and the nut from rotating relative to each other.