Single Drive Shaft Cam Actuation for Load Interrupters

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Solution Overview

Problem

Existing medium-voltage switchgear load-break switches have complex and costly designs due to separate drives and shafts for main and clearing contact systems, which complicates their construction and increases costs.

Innovation Solution

A single drive shaft with a cam disk is used to actuate both the main and clearing contact systems, eliminating the need for a second drive and shaft, and incorporating an insulating medium in the housing for reduced dimensions and improved dielectric properties, allowing for a compact and cost-effective structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate drives and drive shafts are used for main and quenching contact systems, then reliable actuation of both contact systems is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvereliable actuationVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate drive systems into a single drive mechanism that actuates both the main contact system and quenching contact system through a shared drive shaft. This merging reduces the number of components, simplifies the overall structure, and lowers manufacturing costs while maintaining the functional reliability of both contact systems through carefully designed cam mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single drive shaft serves multiple functions by incorporating different cam mechanisms that can independently control both the main contact system and quenching contact system. This multi-functional design allows one component to perform the work of what would traditionally require two separate drive systems, reducing complexity without sacrificing actuation reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate drives and drive shafts are used for main and quenching contact systems, then independent control of contact systems is achieved, but manufacturing cost increases

Engineering Contradiction:
Improveindependent controlVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple drive functions into a single drive shaft with integrated cam mechanisms, reducing the number of parts that need to be manufactured and assembled. This consolidation lowers manufacturing costs while the cam design maintains the ability to independently control each contact system's actuation sequence and timing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single drive shaft is segmented into different functional zones with distinct cam mechanisms for controlling the main contact system and quenching contact system. This segmentation allows independent control of each system while using a unified drive structure, achieving cost savings without sacrificing control versatility.

Inventive Principle:
Principle #1Segmentation

3Reliability

If housing is filled with insulating medium, then dielectric properties and compactness are improved, but manufacturing complexity increases

Engineering Contradiction:
Improvedielectric propertiesVSAvoidhousing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent fills the housing with an insulating medium (inert atmosphere) to improve dielectric properties and enhance the reliability of the switching device. This inert environment prevents unwanted electrical breakdown and improves the overall performance of the contact systems while the housing design accommodates this medium.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The housing acts as a flexible container that can be filled with insulating medium, creating a compact enclosed structure. This approach allows the housing to serve both as a mechanical support structure and as a dielectric barrier, improving compactness without requiring additional separate insulation components.

Inventive Principle:
Principle #30Flexible shells and thin films

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 design simplifies the structure, reduces costs, and enhances the switching device's efficiency by enabling a single bushing for the drive shaft, while maintaining effective arc quenching and dielectric isolation during switching operations.

Implementation Method 1

the switching device can be reduced in overall dimensions by using an insulating medium, for example, an insulating gas or an insulating liquid, as such insulating gases or liquids have improved dielectric properties

Methodology Applied
Scientific EffectDielectric properties: Dielectric

Implementation Method 2

a single cam disk for transmitting the drive movement has a main contact system cam track for actuating the main contact system and a quenching contact system cam track for actuating the quenching contact system

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 3

a quenching contact system for extinguishing an arc during a switching operation

Methodology Applied
Scientific EffectArc quenching: Electric Arc

Data Source

PatentEP2810288B1Switching device, in particular load interrupter
Publication Date: 2019.12.04 SIEMENS AG
  • EP2810288B1 patent drawingFigure 1
  • EP2810288B1 patent drawingFigure 2

AI summary

In order to develop a switching device (1), in particular a load interrupter for medium-voltage switchgear assemblies, comprising a main contact system (4) and a quenching contact system (5) connected in series to the main contact system (4), wherein the main contact system (4) and the quenching contact system (5) are arranged linearly one behind the other, said switching device having a simple and compact and thus low-cost design, it is proposed that a single drive is provided for introducing a driving motion into a single drive shaft of the switching device (1), wherein a single cam disk (14) for transmitting the driving motion has a main contact system curved path (16) for actuating the main contact system (4) and a quenching contact system curved path (15) for actuating the quenching contact system (5).