Insertion-Extraction Mechanism for Medium-Voltage Switchgear

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Solution Overview

Problem

Existing medium-voltage switchgear insertion-extraction mechanisms are cumbersome, requiring significant time and effort to establish connections between movable and stationary contacts, often necessitating high precision and physical exertion to overcome elastic clamping resistance.

Innovation Solution

A structurally simple insertion-extraction mechanism utilizing a driving-lever and displacing means, including extracting protrusions and a transmission shaft, which provides mechanical advantage to reduce the physical effort required for inserting or extracting a circuit breaker, facilitating quick-type clamping connections while ensuring safety and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bolts and nuts are used to fasten movable and stationary contacts, then reliability and safety are improved, but operation time and complexity increase significantly

Engineering Contradiction:
Improveconnection reliabilityVSAvoidconnection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the traditional bolt-nut fastening system with a spring-loaded contact system. The movable contact carries a spring that exerts elastic force to clamp the stationary contact, eliminating the need for threaded fasteners. This substitution maintains reliable electrical connection while dramatically reducing connection time and operational complexity.

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

Solution Approach 2:

The spring-loaded contact system is self-adjusting and self-maintaining. The spring automatically maintains constant contact pressure between movable and stationary contacts, compensating for wear and dimensional variations without requiring manual adjustment or tightening operations, thus ensuring continuous reliable connection.

Inventive Principle:
Principle #25Self-service

2Productivity

If tulips-contacts or pliers-contacts are used with worm-screw-mechanism, then connection speed is improved, but alignment precision requirements increase

Engineering Contradiction:
Improveconnection speedVSAvoidalignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs a dynamic spring-loaded contact system where the spring allows for automatic adjustment and absorption of misalignment. The elastic element provides compliance that accommodates dimensional variations and assembly tolerances, reducing the stringency of alignment precision requirements while maintaining quick connection capability.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If manual pushing is used for quick-type-connection, then structural complexity is reduced, but physical effort required increases

Engineering Contradiction:
Improvemechanism complexityVSAvoidoperator effort
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The patent introduces a lever mechanism as an intermediary between the operator and the contact system. The lever acts as a force amplifier, converting a small operator input force into a large clamping force through mechanical advantage. This intermediary device maintains structural simplicity while eliminating the need for operator to directly apply large forces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The lever mechanism utilizes curved or angled geometries to create mechanical advantage. By positioning the fulcrum and applying force at strategic points along the lever arm, the system amplifies the operator's input force to generate sufficient clamping pressure for reliable contact engagement.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 mechanism significantly simplifies the insertion and extraction processes, reducing operator effort and ensuring reliable engagement/disengagement of contacts with minimal external force, enhancing safety and efficiency in medium-voltage switchgear operations.

Implementation Method 1

a spring (23) arranged for exerting on the movable contact (7) an elastic force

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A structurally simple insertion-extraction mechanism utilizing a driving-lever and displacing means, including extracting protrusions and a transmission shaft, which provides mechanical advantage to reduce the physical effort required

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP3167518B1Insertion-extraction-mechanism
Publication Date: 2018.05.23 ABB (SCHWEIZ) AG
  • EP3167518B1 patent drawingFigure 1~2
  • EP3167518B1 patent drawingFigure 3~4
  • EP3167518B1 patent drawingFigure 5~7

AI summary

An insertion-extraction-mechanism (1) for inserting/extracting a switching-device (2) in/from a switchgear (3), comprises: - displacing-means (4, 14) configured for exerting on the switching-device (2) a force (5) so as to move in a first direction (6) movable contacts (7) of the switching-device (2) with respect to stationary contacts (8) of the switchgear (3), and - driving-lever-means (9) configured for operating, through an external-driving-force (12) the displacing-means (4, 14). The driving-lever-means (9) are further configured for exerting on the switching-device (2), upon an external-motion-force (13), a respective force (10) so as to move in a second direction (11), opposite the first direction (6), the movable contacts (7) with respect to the stationary contacts (8).