Anti-Loosening Screw Pair Using Segmented Thread Contact

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Solution Overview

Problem

Threaded connections in mechanical systems are prone to loosening under conditions like vibration and alternating temperatures, leading to reduced connecting force and potential safety hazards.

Innovation Solution

An anti-loosening screw pair is designed with a first screw component having an inner screw thread and a second screw component with an outer screw thread, featuring force-bearing and non-force-bearing fitting faces with stoppers to prevent radial displacement, ensuring secure engagement and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional threaded connection is used, then the connection is easy to assemble and disassemble, but the connection is prone to loosening under vibration and alternating temperatures

Engineering Contradiction:

Improveanti-loosening performanceVSAvoidthreaded connection structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The threaded connection is divided into force-bearing fitting faces and non-force-bearing fitting regions, with stoppers positioned in the non-force-bearing regions. This segmentation allows the connection to maintain simplicity while adding anti-loosening functionality through discrete stopper elements that prevent radial displacement without interfering with the primary force-bearing surfaces.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Stoppers act as intermediary elements between the force-bearing fitting faces and the external environment. These stoppers prevent radial displacement and loosening under vibration and temperature changes without directly interfering with the force transmission paths, thus maintaining connection reliability while preserving the simplicity of the threaded structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If stoppers are added to prevent radial displacement, then anti-loosening performance is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveradial displacement preventionVSAvoidthreaded component production

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Stoppers are strategically positioned only in non-force-bearing fitting regions where they do not interfere with load transmission. This local quality approach ensures that the majority of the threaded surface maintains its original manufacturing simplicity while adding anti-loosening functionality only where needed, minimizing the impact on ease of manufacture.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of modifying the entire threaded surface, stoppers are applied partially only in non-force-bearing regions. This partial action approach adds the necessary anti-loosening function without requiring complete redesign or modification of the entire threaded component, thus maintaining relatively simple manufacturing processes.

Inventive Principle:

Principle #16Partial or excessive action

3Force

If force-bearing fitting faces are used for connection, then connecting force is maximized, but radial displacement cannot be prevented without affecting force transmission

Engineering Contradiction:

Improveconnecting forceVSAvoidradial displacement control

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The fitting surfaces are segmented into force-bearing regions that maximize connecting force transmission and non-force-bearing regions that accommodate stoppers for radial displacement control. This segmentation allows both functions to operate independently without interfering with each other, maintaining maximum connecting force while effectively preventing loosening.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Stoppers serve as intermediary elements that control radial displacement without directly interfering with the force-bearing fitting faces. By positioning stoppers in non-force-bearing regions, they mediate between the need for radial displacement prevention and the need to maintain optimal force transmission paths, allowing both objectives to be achieved simultaneously.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11268564B2Anti-loosening screw pair and anti-loosening screw component

Publication Date: 2022.03.08 BEIJING INST OF TECH

AI summary

The present disclosure provides an anti-loosening screw pair and an anti-loosening screw component. The screw pair includes a first screw component provided with a first screw thread and a second screw component whose outer wall surface is provided with a second screw thread. The first and second screw components are in threaded connection. In a direction of the first screw component being screwed into the second screw component, sides of the first and second screw threads pressing against each other are formed into force-bearing fitting faces respectively, and opposite sides thereof are formed into non-force-bearing fitting regions respectively. At least one of the force-bearing fitting faces and the non-force-bearing fitting regions of the first and the second screw components is provided with a stopper so as to prevent radial displacement between the first and the second screw components.