Electromagnetic Contactor L-Shaped Contact Conductor Lorentz Force
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Solution Overview
Problem
Existing electromagnetic contactors face challenges in reducing size due to increased height caused by C-shaped fixed contact terminals and suffer from unstable contact and decreased short circuit resistance due to electromagnetic repulsion forces, requiring higher urging forces for the contact spring.
Innovation Solution
The design incorporates L-shaped or C-shaped contact conductor portions with a connecting plate portion extending to the upper plate side, generating a Lorentz force that counters electromagnetic repulsion, allowing for a reduced contact spring urging force and smaller device size, while also forming a magnetic field to enhance contact stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If C-shaped fixed contact terminals are used to support a permanent magnet, then the permanent magnet can be positioned in a corner portion, but the height increases and the size of the contact device cannot be reduced
Solution Approach 1:
The contact conductor portion is configured with a connecting plate that extends in a direction substantially perpendicular to the contact portion, creating an L-shaped or C-shaped structure. This dimensional arrangement allows the permanent magnet to be positioned effectively while reducing the overall height of the contact device by utilizing horizontal space instead of vertical space.
2Power
If large current flows through the contacts, then the electromagnetic contactor can handle high power, but electromagnetic repulsion force is generated that destabilizes contact and decreases short circuit resistance performance
Solution Approach 1:
The patent utilizes the electromagnetic repulsion force generated by large current flow and converts it into a beneficial effect. The connecting plate portion of the contact conductor is positioned to generate a Lorentz force that acts in the contact closing direction, counteracting the harmful electromagnetic repulsion force and maintaining stable contact even under high current conditions.
3Reliability
If electromagnetic repulsion force is countered by increasing contact spring urging force, then contact stability can be maintained, but the height of the contact device increases
Solution Approach 1:
The patent replaces the purely mechanical contact spring urging force with an electromagnetic Lorentz force generated by the connecting plate portion of the contact conductor. This electromagnetic force counteracts the electromagnetic repulsion force, allowing for reduced mechanical urging force and consequently reduced contact device height while maintaining contact stability.
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
This configuration effectively reduces the size of the contact device, maintains stable contact between movable and fixed contacts, and improves short circuit resistance performance by generating a Lorentz force to counter electromagnetic repulsion, thereby minimizing the contact spring's urging force.
Implementation Method 1
a magnetic field generated by the current flowing through the connecting plate portion
Implementation Method 2
a Lorentz force pressing the movable contact to the fixed contact portion side is generated
Data Source
AI summary
An electromagnetic contactor has a contact device including a pair of fixed contacts disposed maintaining a predetermined distance and a movable contact disposed to be capable of contacting to and separating from the pair of fixed contacts. The pair of fixed contacts each includes a support conductor portion supported by an upper plate of a contact housing case, and a contact conductor portion connected to an end portion of the support conductor portion. The contact conductor portion includes a contact plate portion formed with a contact portion, and a connecting plate portion formed on an outer end portion of the contact plate portion and extending to the upper plate side. The movable contact is mounted onto a connecting shaft connected to a drive portion through a contact spring on an end portion on the upper plate side, and disposed to face the contact portion of the pair of fixed contacts.