Circuit Breaker Contact Structure With Ribbed Cooling Paths

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Solution Overview

Problem

Existing contact structures in circuit breakers suffer from ineffective heat rejection due to non-detachable annular rings, leading to inefficient cooling of contact arms, and the inability to replace damaged components.

Innovation Solution

A detachable connecting means with ribs is introduced on the contact arm, allowing for improved heat dissipation through streamlined airflow and increased surface area, using a nut and bolt assembly for attachment and made of high thermal conductivity materials to ensure effective heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If annular rings are provided around each contact arm for heat rejection, then heat dissipation is achieved, but the heat is dispersed rather than streamlined resulting in ineffective cooling

Engineering Contradiction:
Improveheat dissipationVSAvoidcooling effectiveness
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The contact arm is segmented into multiple parallel ribs that create distinct cooling paths. This segmentation allows cool air to flow through multiple channels simultaneously, improving cooling effectiveness while maintaining a compact structure. The ribs divide the heat dissipation function into multiple parallel pathways rather than relying on a single annular ring.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a two-dimensional annular ring configuration to a three-dimensional ribbed structure with multiple cooling paths. The parallel ribs extend in the longitudinal direction, adding a dimensional aspect that enables streamlined airflow through the structure, converting dispersed heat rejection into directed thermal management.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If annular rings are provided around contact arms, then heat rejection is achieved, but the contact structure size must be enlarged

Engineering Contradiction:
Improveheat rejectionVSAvoidcontact structure size
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

Instead of using a single large annular ring that would increase overall structure size, the heat rejection function is segmented into multiple smaller parallel ribs. This segmentation allows the same heat dissipation capacity to be achieved within a more compact footprint, as the ribs can be arranged closely in parallel without requiring the circumferential space of an annular ring.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple ribs are nested within the cross-sectional area of the contact arm, utilizing the internal space efficiently. This nesting approach allows the cooling structure to be embedded within the existing contact arm dimensions rather than adding external annular rings that would increase the overall envelope size.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Temperature

If annular rings are provided on contact arms, then heat dissipation is improved, but the rings are not detachable and cannot be replaced when damaged

Engineering Contradiction:
Improveheat dissipationVSAvoidcomponent replaceability
Core Design Contradiction:
TemperatureVSEase of repair

Solution Approach 1:

The contact arm is segmented into modular ribs that can be independently manufactured and attached. This segmentation enables the cooling ribs to be produced as separate replaceable components rather than being integral to the contact arm, allowing damaged ribs to be replaced without replacing the entire contact arm assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces dynamic replaceability to the previously static contact arm structure. The ribs are designed to be attachable and detachable, transforming the contact arm from a fixed monolithic structure to a modular assembly where cooling components can be dynamically added, removed, or replaced based on operational needs or damage.

Inventive Principle:
Principle #15Dynamics

4Productivity

If multiple parallel ribs are used to streamline cool air flow, then cooling effectiveness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The complex cooling function is segmented into multiple simple parallel ribs rather than attempting to create a single complex annular structure. This segmentation simplifies manufacturing by breaking down the cooling function into repetitive, standardized rib elements that can be produced using conventional machining or molding processes, then assembled together.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of designing a single optimized complex cooling structure, the invention uses multiple simpler rib elements that collectively achieve the cooling function. This partial action approach allows each rib to be manufactured independently using standard processes, and the cumulative effect of multiple ribs provides the desired cooling performance without requiring advanced manufacturing capabilities.

Inventive Principle:
Principle #16Partial or excessive action

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 solution enhances heat dissipation from contact arms, allowing for increased temperature ratings and improved performance without enlarging the contact structure, maintaining proper insulation and preventing current leakage.

Implementation Method 1

The ribs are arranged on the detachable connecting means to define one or more cooling paths. For example, the ribs are arranged parallel to each other and a cool air flow is introduced onto the ribs. The ribs streamline the cool air flow such that the cool air flows between the ribs arranged in parallel.

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The contact structure includes a contact piece with one or more contact arms attached to the contact piece... At least one contact arm comprises two sidewalls with surfaces... The detachable connecting means is provided on the contact arm... to enhance heat dissipation from contact arms

Methodology Applied
Scientific EffectThermal Radiation: Thermal Radiation

Data Source

PatentEP3171381B1Contact structure of a circuit breaker
Publication Date: 2024.09.04 SIEMENS AG
  • EP3171381B1 patent drawingFigure 1
  • EP3171381B1 patent drawingFigure 2
  • EP3171381B1 patent drawingFigure 3A~3B

AI summary

To create a contact structure (5) of a circuit breaker, which provides the contact structure (5) with improved heat rejection from contact arms of the circuit breaker, it is suggested, that a detachable connecting means (6) is provided on the at least one contact arm (3) and a plurality of ribs (7) is formed on the detachable connecting means (6); wherein the plurality of ribs (7) define at least one cooling path (9).