Electromagnetic Contact Load Support for Low-Voltage Switch Separation

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Solution Overview

Problem

Existing low-voltage switching devices face challenges in maintaining effective contact load support as current increases, leading to increased repulsive forces that complicate contact separation and result in higher manufacturing costs and energy consumption, while also suffering from contact erosion issues that require complex mechanics and frequent adjustments.

Innovation Solution

The implementation of a low-voltage switching device with a dual electromagnetic contact load support system using U-shaped ferromagnetic sheets and spring plates, where the magnetic flux induces a high attractive force at low currents and saturates quickly at high currents, allowing for efficient contact separation, and the angled pole surfaces compensate for wear and tolerances, maintaining consistent force throughout the device's lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the device is dimensioned to handle higher currents, then the rated current capacity increases, but the device dimensions, energy consumption, and manufacturing costs increase disproportionately

Engineering Contradiction:
Improverated current capacityVSAvoiddevice dimensions
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent changes the magnetic properties of the contact load support by using a ferromagnetic material with specific permeability characteristics. This allows the support to be magnetically attracted to the contact carrier under normal conditions, providing adequate contact pressure without requiring oversized mechanical components. The parameter change in magnetic permeability enables the same device to handle higher currents without proportionally increasing device dimensions.

Inventive Principle:
Principle #35Parameter changes

2Force

If ferromagnetic bodies are used to increase contact pressure through magnetic attraction, then contact load support improves, but contact separation becomes increasingly difficult at higher currents

Engineering Contradiction:
Improvecontact pressureVSAvoidcontact separation
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The contact load support features a locally optimized geometry with a specific pole surface area and air gap distance to the contact carrier. This local quality design ensures that the magnetic attraction force is sufficient for contact pressure but can be overcome by the electromagnetic drive force during separation. The localized magnetic field concentration at the pole surface provides high contact pressure without creating excessive overall magnetic binding that would prevent separation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically balances magnetic attraction and electromagnetic drive forces. During normal operation, the ferromagnetic contact load support is statically attracted to the contact carrier, providing stable contact pressure. During switching operations, the dynamic electromagnetic drive force overcomes this magnetic attraction to separate the contacts. The design ensures the magnetic bond is strong enough for contact pressure but weak enough to allow controlled separation by the drive mechanism.

Inventive Principle:
Principle #15Dynamics

3Force

If U-shaped ferromagnetic elements are used to amplify contact load, then contact load support improves, but the system requires complex mechanics and frequent adjustments for contact erosion

Engineering Contradiction:
Improvecontact load amplificationVSAvoidmechanical complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent extracts the magnetic field generation function from complex mechanical adjustment systems and concentrates it in a simple ferromagnetic contact load support element. By using the inherent magnetic properties of ferromagnetic materials and the current flowing through the contact carrier, the system achieves contact load amplification without requiring complex U-shaped ferromagnetic element mechanisms or frequent mechanical adjustments. The solution takes out the essential magnetic attraction function and implements it through a simplified single-element design.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This solution provides easy-to-implement electromagnetic contact load support that maintains effective contact separation and compensates for wear, reducing manufacturing costs and energy consumption while ensuring consistent performance over the device's lifespan.

Implementation Method 1

the current flowing in the contact carrier induces a magnetic flux in the ferromagnetic contact load support

Methodology Applied
Scientific EffectMagnetic flux induction: Electromagnetic Induction

Implementation Method 2

This solution exploits the magnetic attraction that the magnetic field of the current flowing through the contact exerts on a ferromagnetic body

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP3494585B1Low-voltage switching device having an electromagnetic contact load support
Publication Date: 2023.09.06 SIEMENS AG
  • EP3494585B1 patent drawingFigure 1
  • EP3494585B1 patent drawingFigure 2~4
  • EP3494585B1 patent drawingFigure 5~6

AI summary

The invention relates to a low-voltage switching device comprising an electromagnetic drive having a coil (1), a fixedly positioned yoke (2), and an armature (3), which is movable relative to the yoke (2), and also comprising a contact system consisting of a fixedly positioned switch piece carrier (4) having a movable switch piece carrier (5) arranged opposite thereto, wherein the movable switch piece carrier (5) is acted upon by a contact load spring (7). The invention is characterized in that a first means for electromagnetic contact load support is positioned on the fixedly positioned switch piece carrier (4).