Overhead Contact Line Conical Clamping and Thermal Compensation

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Solution Overview

Problem

Existing overhead contact line systems experience disruptions in power transmission, sparking, and arcing when vehicles traverse tunnels or structures, leading to interference with radio communications and increased mechanical wear due to uneven conductor rail levels.

Innovation Solution

The overhead contact line system incorporates conically tapering projections on crossbeams for improved clamping, pivot bolts with adjustment devices for superelevation compensation, spring-connected support arms for vibration damping, a connecting device for level maintenance, and an electrical connector for gradual rigidity increase, ensuring stable and efficient power transmission with reduced sparking and arcing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional clamping fittings are used to secure the overhead conductor rail, then the structure is simple, but the electrical contact is poor leading to disruptions in power transmission and sparking

Engineering Contradiction:
Improvepower transmission stabilityVSAvoidclamping structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs conically tapering projections on the crossbeam that fit into corresponding recesses in the clamping fitting. This conical geometry creates a form-fitting connection that ensures stable electrical contact and reliable power transmission while maintaining structural simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent modifies the clamping fitting design by incorporating conically tapering projections with specific geometric parameters. These parameter changes in the connection geometry improve the electrical contact quality and power transmission stability without significantly increasing overall device complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the overhead conductor rail is fixed rigidly to the structure, then the position is stable, but thermal expansion causes the rail to run wavy and creates potential differences leading to sparking

Engineering Contradiction:
Improveelectrical contact continuityVSAvoidrail position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces movable support arms with pivot bolts that allow the overhead conductor rail to rotate and adjust its position. This dynamic capability enables the rail to accommodate thermal expansion and contraction while maintaining stable electrical contact, preventing the rail from running wavy and avoiding potential differences that cause sparking.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent explicitly addresses thermal expansion by designing the support system with pivot bolts and adjustment devices that allow the rail to expand and contract along its length. The movable support arms compensate for thermal effects, maintaining rail position stability and electrical contact continuity despite temperature variations.

Inventive Principle:
Principle #37Thermal expansion

3Reliability

If the support arms are fixed without adjustment capability, then the installation is simple, but the axis misalignment in superelevated sections causes vibrations and poor power transmission

Engineering Contradiction:
Improvepower transmission qualityVSAvoidinstallation simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent incorporates adjustment devices between the structure and pivot bolts that enable the axis of rotation to be aligned perpendicular to the rail head contacting point. This adjustment capability ensures proper alignment in superelevated sections, reducing vibrations and improving power transmission quality while maintaining reasonable installation simplicity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent provides adjustment mechanisms that allow modification of the support arm orientation parameters. By changing the angular parameters of the support arms through adjustment devices, the system achieves proper alignment in curved and superelevated sections, improving power transmission without excessive installation complexity.

Inventive Principle:
Principle #35Parameter changes

4Strength

If the conductor rail is allowed to move freely to compensate thermal expansion, then thermal stress is reduced, but the rail becomes unstable and creates potential differences with holders

Engineering Contradiction:
Improvethermal stress resistanceVSAvoidelectrical contact stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces clamp fittings as intermediary elements between the overhead conductor rail and the support structure. These fittings provide stable electrical contact while allowing the rail to move freely for thermal compensation. The clamp fittings act as a mediator that decouples the mechanical support function from the electrical contact function, enabling thermal expansion without creating potential differences.

Inventive Principle:
Principle #24Intermediary (Mediator)

5Reliability

If additional components are added to improve clamping and reduce sparking, then the electrical contact improves, but the device complexity increases

Engineering Contradiction:
Improvecurrent transmission efficiencyVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the clamping function and electrical contact function into an integrated clamp fitting design. The conically tapering projections on the crossbeam that fit into recesses in the clamping fitting simultaneously provide mechanical retention and stable electrical contact. This merging of functions improves current transmission efficiency without significantly increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 system achieves enhanced current transmission, minimized sparking and arcing, improved driving dynamics, and reduced mechanical wear by providing a stable and level contact interface between the conductor rails and the pantograph, ensuring reliable power delivery and communication integrity.

Implementation Method 1

The spring presses with its free spring arms on the top of the overhead conductor rail. This dampens the vibrations of the power rail

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 2

The conically tapering projections of the crossbeams and the corresponding recesses in the clamping fittings enable a good form-fitting connection with high holding power and low electrical resistance

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

thermal expansion of the busbar can be compensated for by a simple rotation of the pivot pin

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2878480B1Overhead line system
Publication Date: 2018.11.14 SIEMENS MOBILITY GMBH
  • EP2878480B1 patent drawingFigure 1
  • EP2878480B1 patent drawingFigure 2~3
  • EP2878480B1 patent drawingFigure 4~6

AI summary

The invention relates to an overhead contact line system with ceiling conductor rails (1, 16), each of which is fixed in its central region to a structure (14) by a fixed point and otherwise connected to the structure (14) via movable support arms (11). It is provided that at least one of the ceiling conductor rails (1, 16) has a crossbeam (2) on its upper side, from which two downward-pointing tension arms (8) extend at connection points for holding a guide wire (9), and that the crossbeam (2) has conically tapered projections (3) on both sides from the connection points of the tension arms (8), which can be inserted into corresponding recesses (4) of a clamping fitting (5).