Magnetic Switch Contact Structure for Stronger Arc Interruption
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Solution Overview
Problem
Conventional switches face challenges in increasing the arc driving force and improving arc discharge interruption performance, especially during current interruption, regardless of the energization direction of the current flowing through the movable contactor.
Innovation Solution
A switch design featuring a first and second fixed contactor, a movable contactor with permanent magnets of identical polarity sandwiching it, and a magnetic yoke with protrusions to enhance magnetic flux density and arc driving force, allowing for improved arc discharge interruption performance regardless of current direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent magnets are arranged to sandwich the movable contactor with identical polarity surfaces facing the movable contactor, then the arc driving force is increased and arc discharge interruption performance is improved, but the device complexity increases due to additional magnetic components
Solution Approach 1:
The magnetic field generation is segmented into multiple permanent magnets arranged in pairs on opposite sides of the movable contactor. Each pair generates a localized magnetic field that contributes to the overall arc driving force, allowing the system to achieve enhanced performance through distributed magnetic components rather than a single complex magnetic system.
Solution Approach 2:
The invention changes the magnetic field parameters by using permanent magnets with identical polarity surfaces facing the movable contactor. This configuration creates a specific magnetic field distribution that enhances the arc driving force. The magnetic field strength and distribution are optimized by adjusting the number, size, and positioning of the permanent magnet pairs.
2Reliability
If a yoke with protrusion is added to concentrate magnetic flux at the contactor end, then the arc driving force is further enhanced, but the manufacturing complexity and cost increase
Solution Approach 1:
The yoke is designed with a protrusion that locally concentrates magnetic flux at the end portion of the movable contactor where the first movable contact is located. This localized flux concentration enhances the arc driving force specifically at the contact separation point without requiring uniform magnetic enhancement throughout the entire contactor structure, optimizing manufacturing efficiency.
Solution Approach 2:
The yoke acts as an intermediary magnetic component that bridges the permanent magnets and the movable contactor. The protrusion on the yoke serves as a flux concentrator that directs and intensifies the magnetic field at the critical contact region, mediating between the distributed permanent magnets and the specific location where arc interruption is needed.
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 effectively increases the arc driving force and improves arc discharge interruption performance immediately after current interruption, achieving higher interruption efficiency compared to conventional techniques.
Implementation Method 1
at least a pair of permanent magnets arranged to sandwich the movable contactor and to cause their surfaces facing the movable contactor in a third direction perpendicular to the first direction and the second direction of the movable contactor to have an identical polarity
Implementation Method 2
a yoke made of a magnetic material surrounding a periphery of the movable contactor in the first direction and the third direction and connected to surfaces of the permanent magnets on opposite sides
Implementation Method 3
the yoke includes a protrusion protruding toward the movable contactor at a position facing the first end portion of the movable contactor in the first direction
Implementation Method 4
the arc driving force for driving the arc discharge generated immediately after the start of the current interruption can be increased
Data Source
AI summary
A switch includes a first fixed contactor, a second fixed contactor, a movable contactor, permanent magnets, and a yoke. The movable contactor extends in a first direction, includes a first movable contact at a first end portion, and is provided to be contactable with and separatable from the first fixed contactor in a second direction. The permanent magnets are arranged to sandwich the movable contactor, and to cause their surfaces facing the movable contactor in the third direction of the movable contactor to have the same polarity. The yoke surrounds a periphery of the movable contactor in the first direction and the third direction and is connected to surfaces of the permanent magnets on opposite sides of their surfaces facing the movable contactor. The yoke includes a protrusion protruding toward the movable contactor at a position facing the first end portion of the movable contactor in the first direction.