Captive Connector Assembly for 3D Vibration-Damped Mounting

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Solution Overview

Problem

Conventional connections fail to provide a vibration-safe and shock-decoupled connection that absorbs vibrations in all directions, is easily fastened and released, and has a captive, detachable lock that can only be tightened with a defined torque, especially when mounting vibrating devices like motors or fans on fixed bearings.

Innovation Solution

A connection system comprising a threaded sleeve, damping washers, and a bolt that sandwiches the second part to provide axial damping, with a threaded portion acting as a counter nut to prevent relative rotation, and a circumferential damping cord for lateral damping, allowing for three-dimensional decoupling and easy detachment with a specific torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a conventional connection is used to mount a vibrating device on a fixed bearing, then the connection is simple and easy to manufacture, but the connection does not provide adequate vibration damping in all directions

Engineering Contradiction:
Improvevibration transmissionVSAvoidconnection structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The connection system is divided into multiple functional components: a connector with threaded engagement for secure attachment, a separate damping element with viscoelastic material for vibration absorption, and a fastening mechanism. This segmentation allows each component to specialize in its function while maintaining overall system simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The damping element incorporates viscoelastic material that combines viscous and elastic properties, enabling simultaneous energy dissipation through hysteresis and elastic recovery. This composite material approach provides multi-directional vibration damping without requiring complex structural arrangements

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a vibration-damped connection is implemented, then vibration attenuation is improved, but the connection becomes more complex and harder to manufacture

Engineering Contradiction:
Improveshock transmissionVSAvoidconnection assembly
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The damping function is merged directly into the connector body through integration of the viscoelastic damping element with the connector structure. This merging eliminates the need for separate damping components and complex assembly procedures, allowing the damping function to be manufactured as a single integrated piece

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The damping element acts as an intermediary between the vibrating device and the fixed bearing, absorbing and dissipating shock and vibration energy. This intermediary approach protects the fixed bearing from harmful vibrations while maintaining a straightforward manufacturing process for each component

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a captive connector is used to prevent losing the bolt, then connection reliability is improved, but the ease of operation for fastening and release is reduced

Engineering Contradiction:
Improvebolt retentionVSAvoidfastening and release
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The captive connector design allows the bolt to remain attached to the connector body through threaded engagement, enabling the connector to service itself by preventing bolt loss. The bolt threads engage with both the connector and the workpiece, creating a self-retaining mechanism that maintains reliability while allowing tool-assisted removal when needed

Inventive Principle:
Principle #25Self-service

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 effectively attenuates vibrations in all directions, ensuring secure fastening while allowing for easy detachment and adjustable damping properties, overcoming the limitations of conventional connectors by providing a secure, detachable, and vibration-damped connection.

Implementation Method 1

The one or more damping washers are configured to receive the treaded sleeve and to sandwich the second part to provide a damping in the axial direction

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The damping cord extends in at least one lateral direction between the second part and the first part to provide a lateral damping between the first part and the second part

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4074988B1Connection system and method of connecting
Publication Date: 2024.10.23 HENSOLDT SENSORS GMBH
  • EP4074988B1 patent drawingFigure 1
  • EP4074988B1 patent drawingFigure 2
  • EP4074988B1 patent drawingFigure 3

AI summary

A captive connector for establishing a captive connection between a first part (50) and a second part (60), one of which being a fixed bearing and the other a support element is disclosed. The first part (50) includes a threaded hole (55) and the second part (60) includes an opening (65). The connector comprises: a threaded sleeve (110), one or more damping washers (120), and a bolt (130). The threaded sleeve (110) extends in an axial direction (Z) and configured to be inserted into the opening (65) of the second part (60) with a radial margin (112). The one or more damping washers (120) is/are configured to receive the treaded sleeve (110) and to sandwich the second part (60) to provide a damping in the axial direction (Z). The bolt (130) is configured: to threadedly engage the hole (55) of the first part (50), to threadedly engage the treaded sleeve (110), and to secure the one or more damping washers (120) together with the sandwiched second part (60) at the first part (50). Both treaded engagements prevent losing the bolt (130).