Fan Guard Fastening Sleeve Clamping Mechanism

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Solution Overview

Problem

Existing fastening solutions for fan protection grilles are inadequate in absorbing transverse force loads, often being one-piece and cohesive, which can lead to instability and breakage under the high loads generated by fan motor operation and vibrations.

Innovation Solution

A fastening device with a fastening sleeve that forms a clamping region for a first leg extending over multiple grille bars, featuring a collar to border the clamping area and an axial bracing mechanism, such as a screw connection, to create a clamping force that exceeds the transverse forces, and is designed to stabilize the free longitudinal end of the fastening strut, potentially in a hairpin shape with two legs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fastening elements are implemented as a single piece or with material bond, then manufacturing is simplified, but transverse force loads are not sufficiently absorbed and fatigue strength is reduced

Engineering Contradiction:
Improvefastening element manufacturingVSAvoidtransverse force absorption
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The fastening element is divided into multiple separate components: a mounting strut and a fastening device. This segmentation allows each component to be optimized independently - the mounting strut for structural integrity and the fastening device for transverse force absorption through its clamping mechanism with friction-based grip.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fastening device acts as an intermediary between the mounting strut and the support surface. It provides a specialized interface that absorbs transverse forces through friction and clamping, protecting the mounting strut from direct exposure to these destabilizing loads.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If fastening elements are implemented as a single piece or with material bond, then structural simplicity is maintained, but fatigue strength properties are reduced

Engineering Contradiction:
Improvefastening structureVSAvoidfastening element service life
Core Design Contradiction:
Device complexityVSDuration of action of stationary object

Solution Approach 1:

The fastening system is segmented into distinct functional components that can be independently optimized. The mounting strut maintains structural simplicity while the separate fastening device provides enhanced fatigue resistance through its clamping and friction-based retention mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fastening device changes the mechanical parameters at the fastening point by creating a clamped connection with controlled friction. This transforms the stress distribution and significantly improves fatigue strength properties compared to simple material bonding or single-piece construction.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If attachment points are designed for high load absorption, then stability is improved, but transverse forces may still cause breakage without proper design

Engineering Contradiction:
Improveattachment point stabilityVSAvoidresistance to transverse forces
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The fastening device serves as a protective intermediary that absorbs and dissipates transverse forces through friction and clamping. This shields the mounting strut from direct exposure to destabilizing transverse loads while maintaining attachment stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fastening device converts potentially harmful transverse forces into beneficial compressive clamping forces. The friction generated by these forces enhances the gripping action, transforming a destabilizing influence into a stabilizing mechanism that prevents breakage.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 solution enhances the fatigue strength and moment capacity of the fastening point, ensuring the fastening device can absorb the actual transverse forces and maintain stability during operation, thereby increasing the service life of the fan protection grille.

Implementation Method 1

a clamping force Fsp for bracing and/or clamping is realized in the clamping area by the fastening sleeve... both the required clamping forces of the clamping area and the absorbable transverse forces are above the actually occurring transverse forces Fq, whereby the transverse forces are formed by Fq = μ * Fsp (μ corresponds to the coefficient of friction between the clamped components)

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3431776B1Fastening of a mounting strut for a protective fan guard
Publication Date: 2024.02.14 EBM PAPST MULFINGEN GMBH & CO KG
  • EP3431776B1 patent drawingFigure 1~2
  • EP3431776B1 patent drawingFigure 3

AI summary

The invention relates to a fastening device for fastening a fastening strut for a fan guard grille (50), which has at least one first leg (11) extending in a longitudinal direction and configured to overlap several grille bars (3) of the fan guard grille (50), wherein the at least one first leg (11) has a free longitudinal end, and the fastening device (13) is arranged in the region of the free longitudinal end of the at least first leg (11), characterized in that the fastening device (13) comprises a fastening sleeve (14) configured such that at least one clamping area (19) receiving at least the first leg (11) is formed and supported.