Retaining Structure for High Voltage Dead Tank Breaker Linkage

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Solution Overview

Problem

High voltage dead tank circuit breakers face the challenge of losing factory pretension on their linkage structure when the operating mechanism is removed, posing safety risks during shipping and servicing.

Innovation Solution

A linkage structure with a lever, connection rod, and open spring is designed, along with a retaining structure that redirects the spring force from the lever to a screw, allowing safe servicing and maintenance while maintaining pretension, and then restoring it after servicing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the operating mechanism is removed from the linkage for shipping or servicing, then the circuit breaker can be transported more easily and workers are protected from injury, but the factory pretension spring setting on the linkage is lost

Engineering Contradiction:

Improveease of shippingVSAvoidfactory pretension spring setting

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The retaining structure is divided into separate components: a retaining member that engages with the lever, and a screw that adjusts the retention force. This segmentation allows the pretension to be maintained in discrete, adjustable portions rather than as a fixed continuous force.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining structure acts as an intermediary element between the spring and the lever. It intercepts the spring force and redirects it, preventing the force from acting on the linkage components during shipping while allowing easy installation and removal.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the pretension spring setting is maintained during operating mechanism removal, then the factory settings are preserved, but forces remain on the linkage which could injure workers during removal or servicing

Engineering Contradiction:

Improvefactory pretension spring settingVSAvoidworker injury risk

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The harmful spring force is extracted from the linkage system by introducing the retaining structure. The retaining member intercepts and holds the spring force separately, removing the dangerous loading from the linkage components while preserving the spring's pretension capability for later use.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The potentially harmful spring force is converted into a beneficial retained tension. The screw mechanism allows the spring force to be controlled and directed, transforming what would be a dangerous uncontrolled force into a manageable pretension that can be applied safely when needed.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Stability of the object's composition

If the connection rod remains under tension during servicing, then the factory pretension is maintained, but the connection rod cannot be safely serviced or removed

Engineering Contradiction:

Improvefactory pretension spring settingVSAvoidconnection rod servicing

Core Design Contradiction:

Stability of the object's compositionVSEase of repair

Solution Approach 1:

The retaining structure serves as an intermediary that takes over the load-bearing function from the connection rod. By engaging the retaining member with the lever and using the screw to apply retention force, the spring force is redirected away from the connection rod, allowing it to be serviced without bearing tension.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables safe removal and reattachment of the operating mechanism without losing factory pretension, ensuring worker safety and maintaining the circuit breaker's operational settings during shipping and maintenance.

Implementation Method 1

The spring structure includes an open spring providing a spring force on the lever for opening the electrical contact

Methodology Applied

Scientific EffectSpring force: Spring

Implementation Method 2

The retaining structure is adjusted to ensure that the spring force of the open spring, exerted on the lever, is directed to the retaining structure so that tension on the connection rod is removed

Methodology Applied

Scientific EffectMechanical force: Mechanical Force

Data Source

PatentUS8975548B2Retaining structure for maintaining factory settings of gang-style linkage for high voltage dead tank breaker while operating mechanism is removed

Publication Date: 2015.03.10 HITACHI ENERGY LTD

AI summary

Linkage structure is connected between an operating mechanism and an actuating assembly of a circuit breaker for opening and closing an electrical contact of a pole assembly. The linkage assembly includes a lever to connect with the actuating assembly. A connection rod is coupled to one end of the lever and is associated with a close spring for closing the electrical contact. A spring structure is coupled to another end of the lever. The spring structure includes an open spring providing a spring force on the lever for opening the electrical contact. The open spring places the connection rod in tension. Retaining structure is associated with the lever and the spring structure to ensure that the spring force of the open spring, exerted on the lever, is directed to the retaining structure so that tension on the connection rod is removed, enabling the connection rod to be serviced.