Contact Device Permanent Magnet Arrangement Arc Cutoff
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing contact devices face challenges in achieving stable arc cutoff performance while maintaining a compact size, as the arrangement of permanent magnets can lead to increased size and cost, and the magnetic gap between magnets results in weakened arc cutoff forces.
Innovation Solution
A contact device design featuring a pair of permanent magnets with mutually-opposing surfaces of the same polarity, arranged across the contact point block, and a second yoke between the magnets to enhance magnetic flux density and arc drawing-out forces, allowing for stable arc cutoff performance and size reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent magnets are arranged at lateral sides of the movable contactor to strengthen magnetic fields, then arc cutoff performance is improved, but device size increases
Solution Approach 1:
The patent transitions from lateral arrangement of permanent magnets (horizontal dimension) to longitudinal arrangement at opposite ends (longitudinal dimension), changing the spatial dimension of magnet placement to achieve compact lateral profile while maintaining arc cutoff effectiveness
Solution Approach 2:
The patent employs asymmetric polarity arrangement where one permanent magnet has N-pole facing the contactor and the other has S-pole facing the contactor, creating asymmetric magnetic field distribution that effectively draws arcs toward the center while maintaining compact size
2Volume of moving object
If permanent magnets are arranged at longitudinal opposite ends, then device size is reduced, but magnetic gap increases causing weakened arc cutoff forces
Solution Approach 1:
The patent changes the polarity parameter of the permanent magnets from identical (both N or both S) to opposite (one N and one S), which fundamentally alters the magnetic field distribution to concentrate flux in the center region, compensating for the increased magnetic gap distance
Solution Approach 2:
The movable contactor body acts as an intermediary magnetic conductor that bridges the gap between the two permanently magnets with opposite polarities, channeling and concentrating the magnetic flux toward the contact points to maintain strong arc cutoff force despite the longitudinal separation
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 provides stable arc cutoff performance and reduces the size of the contact device while maintaining cost-effectiveness by optimizing the magnetic field distribution and flux density, preventing arc short-circuiting and enhancing contact point switching reliability.
Implementation Method 1
an arc current generated when contact points comes into contact or out of contact with each other is drawn out by a magnetic force of a permanent magnet
Implementation Method 2
the polarities of the mutually-opposing surfaces of the permanent magnets 46 differ from each other... strengthen the magnetic fields flowing across the contact points
Implementation Method 3
a second yoke arranged between the permanent magnets to enhance magnetic flux density and arc drawing-out forces
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A contact device includes a contact point block 3, a drive unit 2, and permanent magnets 46. The contact point block 3 includes fixed terminals 33 having fixed contact points 32 and a movable contactor 35 having movable contact points 34 arranged side by side on one surface of the movable contactor 35. The movable contact points 34 are configured to come into contact and out of contact with the fixed contact points 32. The drive unit 2 drives the movable contactor 35 such that the movable contact points come into contact and out of contact with the fixed contact points. The permanent magnets 46 are arranged in a mutually opposing relationship across the contact point block 3 along a direction orthogonal to an arrangement direction of the movable contact points 34 and to a direction in which the movable contact points 34 come into contact and out of contact with the fixed contact points 32. The permanent magnets 46 are provided with mutually-opposing surfaces having the same polarity.