Overhead Line Dropper With Threshold-Activated Vibration Damping

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Solution Overview

Problem

Existing droppers for overhead lines face issues with complex design, high temperature dependence of damping properties, wear due to mechanical friction, jerky response behavior, and increased maintenance requirements, particularly due to permanent damping leading to loss of contact and arcing.

Innovation Solution

A dropper with a spring-damper element where the spring and damping elements are not positively connected, featuring a tension or compression spring with an impact head that contacts a damping element to absorb vibrations, utilizing damping rings with adjustable preload and shape to minimize temperature dependence and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If permanent damping is applied to the dropper, then vibrations are suppressed, but contact loss and arcing occur when the pantograph is distanced from the contact wire

Engineering Contradiction:
Improvevibration suppressionVSAvoidcontact loss and arcing
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The dropper transitions from a permanently damped system to a dynamic system where damping is activated only when needed. The damping element remains disengaged during normal operation and only contacts the impact head when vibrations exceed a certain threshold, making the damping action conditional and dynamic rather than permanent.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The damping mechanism operates periodically rather than continuously. The impact head contacts the damping element only during vibration events, creating intermittent damping action that suppresses vibrations when they occur while maintaining contact wire connection during normal operation.

Inventive Principle:
Principle #19Periodic action

2Reliability

If permanent damping is applied to the dropper, then vibrations are suppressed, but increased pressure is exerted on the contact wire when the pantograph is raised

Engineering Contradiction:
Improvevibration suppressionVSAvoidpressure on contact wire
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The system dynamically adjusts the force applied to the contact wire by engaging damping only when vibrations occur. During normal operation, the spring element provides only tension without additional damping force, reducing the pressure on the contact wire compared to permanent damping systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spring element is pre-tensioned to provide the necessary contact force, while the damping element is positioned to engage only when vibration-induced movements exceed a threshold. This preliminary setup allows the system to maintain adequate contact force without adding permanent damping pressure.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If solid-state friction damping is used, then damping is provided, but wear occurs and jerky response behavior is generated

Engineering Contradiction:
ImprovedampingVSAvoidwear and maintenance
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The invention replaces solid-state friction damping with impact-based damping. Instead of relying on continuous friction between sliding surfaces, the system uses controlled impact between the impact head and the damping element, which reduces wear and eliminates the jerky response characteristic of friction-based systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The damping element is designed as a replaceable component with a service life longer than friction elements. Once the damping element wears out from impact contact, it can be easily replaced without affecting other components, reducing overall maintenance requirements compared to friction-based systems where wear occurs continuously.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Reliability

If hydraulic or air-filled damper elements are used, then damping is provided, but complicated design and precise axial alignment are required

Engineering Contradiction:
ImprovedampingVSAvoiddesign complexity and alignment requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the damping function from complex hydraulic or air-filled systems and implements it through a simple mechanical impact mechanism. The damping element is a straightforward mechanical component that requires no fluid systems, seals, or precise alignment, significantly reducing design complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The damping element is designed as a simple, inexpensive mechanical component that can be easily manufactured and replaced. This eliminates the need for complex hydraulic or pneumatic systems with multiple moving parts, seals, and alignment requirements, reducing both initial design complexity and maintenance burden.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 provides rapid response to contact pressure changes, reduces maintenance needs, and minimizes high-frequency vibrations, ensuring consistent damping performance with low temperature dependence and reduced wear, leading to improved operational reliability and cost-effectiveness.

Implementation Method 1

a spring-damper element comprising a spring element (7) and a damping element (10)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a damping element (10), arranged to be movable relative to the spring element (7) in the axial direction of the spring element (7), with a frictional connection between the spring element (7) and the damping element (10)

Methodology Applied
Scientific EffectFriction damping: Friction

Data Source

PatentEP4249322A1Dropper with a spring-damper element for overhead lines
Publication Date: 2023.09.27 MOSDORFER
  • EP4249322A1 patent drawingFigure 1~2
  • EP4249322A1 patent drawingFigure 3~4
  • EP4249322A1 patent drawingFigure 5~6

AI summary

The invention relates to a dropper for catenary wires has a spring-damper element, the spring and the damping element not being positively connected to one another, as a result of which, after a pure spring travel, an impact head comes into contact with the damping element, which damps the vibrations of the catenary wire.