Circuit Breaker Cam Rotation Delaying Mechanism

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Solution Overview

Problem

Existing circuit breakers face instability due to excessive cam rotation, which interferes with the toggling operation of the link mechanism and prevents complete return of the closing spring, leading to incomplete closing operations.

Innovation Solution

A cam rotation delaying mechanism is introduced, comprising a delay link and a delay spring that attenuate the rotational force of the cam, using a supplementary cam with a contact groove and a rotation pin to control and slow down the cam's rotation, preventing excessive rotation and ensuring stable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the closing spring force is increased to ensure complete closing operation, then the closing reliability is improved, but the cam rotates excessively beyond its original location causing interference with the driving lever return

Engineering Contradiction:
Improveclosing operation reliabilityVSAvoidcam rotation stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

A cam delaying mechanism is introduced as an intermediary component between the cam and the driving lever. This mechanism includes a delay link rotatably connected to the cam, which mediates the transmission of rotational force and delays the cam's return rotation, preventing excessive rotation while maintaining reliable closing operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cam delaying mechanism performs preliminary action by预先 controlling the cam's rotation speed and position. The delay link and delay spring work together to regulate the cam's return rotation before it can interfere with the driving lever, ensuring stable operation throughout the cycle.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If the cam rotation is delayed to prevent excessive rotation, then the operational stability is improved, but the device complexity increases due to additional components

Engineering Contradiction:
Improveoperational stabilityVSAvoidmechanism complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The cam delaying mechanism employs dynamic elements including a rotatable delay link and a delay spring that provides elastic restoring force. These dynamic components adapt to the cam's rotation throughout the operating cycle, providing delayed rotation control without requiring complex rigid structures or multiple control mechanisms.

Inventive Principle:
Principle #15Dynamics

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 cam rotation delaying mechanism stabilizes the toggling operation of the link mechanism and allows for smooth returning of the closing spring, preventing excessive cam rotation and ensuring more stable and complete circuit breaker operations.

Implementation Method 1

a delay spring (154) installed between the delay link (151) and each plate (100) for elastically supporting the rotation of the delay link (151)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a closing operation for connecting a movable contact to a terminal by an elastic restoring force of the closing spring

Methodology Applied
Scientific EffectElastic energy storage: Elasticity

Data Source

PatentEP2204827B1Circuit breaker with delayed rotatable cam for spring motor
Publication Date: 2016.06.01 LG INDUSTRIAL SYSTEMS CO LTD
  • EP2204827B1 patent drawingFigure 1
  • EP2204827B1 patent drawingFigure 2
  • EP2204827B1 patent drawingFigure 3

AI summary

Disclosed is a circuit breaker having a cam rotation delaying function employed to block current, the circuit breaker performing a charging operation and a charting operation, the circuit breaker including a closing spring having one end portion rotatably coupled to each of plates, a driving lever rotatably installed at each of the plates and connected to another end portion of the closing spring so as to be rotated responsive to compression and extension of the closing spring, a cam rotatably installed at each of the plates and configured to press the driving lever for rotation, a link mechanism having a plurality of links rotatably installed at each of the plates and connected to the driving lever for operation, a movable contact rotatably installed at a side of each of the plates and contactable with a terminal by an operation of the link mechanism, and a cam delaying mechanism installed at each of the plates and configured to attenuate a rotational force of the cam due to a restoring force of the closing spring, whereby an excessive rotation of the cam can be prevented by the cam delaying mechanism so as to allow stable and complete toggling operation of the link mechanism and a smooth restoring operation of the closing spring, thereby providing more stable operation of the circuit breaker.