Pivot-Mounting Nut Structure for Vibration-Resistant Attachment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pivot-mounting devices fail to accommodate varying member thicknesses and prevent loosening due to vibration, especially during repeated attachment and detachment.
Innovation Solution
A pivot-mounting device comprising a bolt and two nuts with a boss and engagement recess, where the boss is eccentric relative to the nut's thread hole, producing perpendicular pressing forces that maintain secure attachment even with varying fit depths, preventing loosening and accommodating different thicknesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single-nut pivot-mounting device is used, then the structure is simple, but it cannot accommodate varying member thicknesses and loosens due to vibration
Solution Approach 1:
The single nut is divided into two separate nuts: a first nut with a boss for supporting one side of the rotatable member, and a second nut with an engagement recess for supporting the opposite side. This segmentation allows each nut to be optimized for specific functions (support and anti-loosening) while together providing stable attachment for varying thicknesses.
Solution Approach 2:
The boss of the first nut is fitted into the engagement recess of the second nut, creating a nested configuration. This nesting mechanism enables the two nuts to work together as an integrated anti-loosening system, where the inner peripheral surface of the engagement recess engages with the outer peripheral surface of the boss to prevent relative rotation and loosening.
2Adaptability or versatility
If the fit depth of the boss with respect to the engagement recess is precisely controlled, then the attachment precision is high, but it cannot accommodate thickness variations
Solution Approach 1:
The engagement between the boss and engagement recess is designed to be dynamic rather than fixed at a precise depth. The inner peripheral surface of the engagement recess and outer peripheral surface of the boss engage circumferentially to produce pressing forces that prevent loosening, while allowing the fit depth to vary within a predetermined range to accommodate different member thicknesses.
Solution Approach 2:
The design allows the fit depth parameter to change within a predetermined range without affecting the anti-loosening function. The pressing forces generated by the eccentric boss-engagement recess interface maintain attachment stability even when the fit depth varies, enabling adaptation to different thicknesses without requiring precise control.
3Reliability
If the outer peripheral surface of the boss and inner peripheral surface of the engagement recess are formed as straight circular shapes, then the device accommodates thickness variations, but the pressing force may be insufficient
Solution Approach 1:
The boss is designed with an outer peripheral surface that is slightly asymmetric relative to the female thread hole axis, and the engagement recess has an inner peripheral surface that is slightly asymmetric relative to its female thread hole axis. This asymmetry ensures that when the boss is fitted into the engagement recess, a circumferential portion engages to generate pressing forces perpendicular to the axis, preventing loosening while maintaining simple straight circular shapes that are easy to manufacture.
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 device provides a simple, reusable configuration that securely attaches rotatable members with varying thicknesses and prevents loosening due to vibration, ensuring stable attachment across different configurations.
Implementation Method 1
an outer peripheral surface of the boss is eccentric relative to the female thread hole of the first nut or an inner peripheral surface of the engagement recess is eccentric relative to the female thread hole of the second nut such that, when the boss is fitted into the engagement recess, a circumferential portion of the outer peripheral surface of the boss engages a circumferential portion of an inner peripheral surface of the engagement recess such that, in each of the first and second nuts, a pressing force in a direction perpendicular to an axis thereof is produced
Implementation Method 2
first and second nuts having female thread holes into which the bolt is screwable
Data Source
AI summary
A pivot-mounting device has a lower nut (4) is fixing a bolt (2) to an object (A), and an upper nut (3) having a boss (32) rotatably supporting a rotatable member (B) is tightened on the bolt (2). A lower nut (4) includes an engagement recess (41) into which the boss (32) can be fitted with the outer peripheral surface of the boss (32) and the inner peripheral surface of the engagement recess (41) each being a straight cylinder shape. The boss outer peripheral surface (32) is slightly eccentric relative to a female thread hole (3a).