Two-Nut Self-Locking Structure for Uniform Bolt Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing self-locking bolts and nuts, such as the Hardlock Nut, apply eccentric pressure leading to uneven thread stress and bending stress on bolts, reducing fatigue strength, making them unsuitable for high-stress applications like engine parts.
Innovation Solution
A self-locking nut design featuring a concave nut with a tapered-cylinder-shaped recess and a matching convex nut with a spiral progressive locking structure, open through grooves, and annular convex-concave pressing reinforcing ribs, ensuring uniform stress distribution and reliable locking without affecting the bolt's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If eccentric pressure is applied to achieve self-locking, then the locking reliability is improved, but the thread stress becomes uneven and bending stress increases, reducing fatigue strength
Solution Approach 1:
The locking function is segmented between two nuts: the first nut provides initial locking, while the second nut with spiral progressive locking structure provides enhanced locking. This segmentation allows each nut to perform its specific function without the first nut bearing the full eccentric load, reducing stress concentration and bending stress on the bolt.
Solution Approach 2:
Instead of applying eccentric pressure directly (which causes uneven stress), the patent uses a spiral progressive locking structure that applies pressure in a reversed sequence - the locking force is gradually applied through the spiral structure, ensuring uniform stress distribution while achieving reliable locking.
2Ease of operation
If a simple locking structure is used, then the ease of operation is improved, but the locking reliability may be insufficient for high-stress applications
Solution Approach 1:
The second nut with spiral progressive locking structure is nested onto the first nut, creating a compact two-nut locking system. This nested design maintains simplicity in installation (both nuts are threaded onto the same bolt sequentially) while achieving high reliability through the combined locking mechanisms of both nuts.
Solution Approach 2:
The spiral progressive locking structure automatically applies locking force as the second nut is threaded onto the first nut, eliminating the need for additional locking operations or tools. The structure serves itself by converting the tightening motion into progressive locking pressure, maintaining ease of operation while ensuring reliable locking.
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 design provides a reliable and efficient locking mechanism that prevents nut loosening without reducing the bolt's fatigue strength, suitable for various applications by distributing stress uniformly and enhancing locking efficiency.
Implementation Method 1
a concave nut (1) having a tapered-cylinder-shaped recess and a matching convex nut (2) having a tapered-cylinder-shaped protrusion
Implementation Method 2
a tapered-cylinder-shaped part of the matching nut is provided with a matching spiral progressive locking structure
Implementation Method 3
matching annular convex-concave pressing reinforcing ribs are arranged on contact faces of the two nuts which match each other
Data Source
AI summary
Provided is a simple and convenient self-locking nut. The simple and convenient self-locking nut consists of a concave nut (1) having a tapered-cylinder-shaped recess and a matching convex nut (2) having a tapered-cylinder-shaped protrusion, wherein a tapered-cylinder-shaped part of the matching nut is provided with a matching spiral progressive locking structure, a convex part of the convex nut is provided with open through grooves, thus forming an intermittent annular progressive locking structure, such that the convex part of the nut locks a bolt (3) while being locked with the concave nut (1), or locking is so tight that intermittent occlusion is formed with a thread of the bolt (3) to enhance the locking efficiency of the bolt (3); and the two nuts and the tapered-cylindrical and annular progressive tightening structure guarantee uniform stress, thus ensuring the reliability of the overall efficacy, and the expected goal that the nut will not come loose after being locked is achieved without affecting the normal characteristics of the bolt.