Contactor Assembly Using Opposing Electromagnetic Forces
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Solution Overview
Problem
In contactors, electromagnetic repulsion forces can prevent or cause improper closure or opening of contacts, leading to increased size requirements for relays and contactors to counteract these forces, which is undesirable.
Innovation Solution
A contactor assembly that generates opposing electromagnetic forces between a contact bridge and conductive pads to resist electromagnetic repulsion forces, allowing for reliable contact engagement and reduced arcing by controlling the mating process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large spring force is provided to overcome electromagnetic repulsion, then contact pressure is maintained and contacts remain closed, but the size of the spring and electromagnet must be increased
Solution Approach 1:
The patent applies the counterweight principle by generating opposing electromagnetic forces between the contact bridge and conductive pads to counteract the electromagnetic repulsion forces. This allows the use of smaller spring forces to maintain contact pressure, thereby reducing the size of the spring and electromagnet components while still keeping contacts properly closed during operation.
Solution Approach 2:
The patent converts the harmful electromagnetic repulsion force into a beneficial effect by using the same electromagnetic field to generate opposing forces that hold the contacts together. The repulsion force that was previously problematic is now harnessed to create the holding force needed to maintain contact closure, eliminating the need for oversized mechanical components.
2Force
If the size of the spring is increased to increase contact pressure, then electromagnetic repulsion is counteracted, but the force generated by the electromagnet must also be increased
Solution Approach 1:
The opposing electromagnetic forces act as a counterweight to the electromagnetic repulsion, allowing the spring force to be reduced while maintaining adequate contact pressure. This consequently reduces the power requirement of the electromagnet since it only needs to overcome the reduced spring force rather than a large spring force designed to counteract repulsion.
Solution Approach 2:
The electromagnetic field that creates repulsion is also used to generate the opposing holding forces, converting what was previously a power-consuming problem into a power-saving solution. The same electromagnetic energy that caused repulsion now provides the holding force, reducing the net power required from the electromagnet.
3Force
If larger electromagnet is used to increase contact pressure, then electromagnetic repulsion is overcome, but the size of the entire structure is increased
Solution Approach 1:
The opposing electromagnetic forces provide a counterbalancing effect that allows the use of a smaller electromagnet to achieve the required contact pressure. This directly reduces the volume of the electromagnet and consequently the overall structure size while maintaining adequate contact force to counteract electromagnetic repulsion.
Solution Approach 2:
By converting the repulsive electromagnetic force into a beneficial holding force, the patent eliminates the need for oversized electromagnets and structural components. The same electromagnetic field serves dual purposes, allowing for a more compact overall structure while maintaining sufficient contact pressure.
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 solution maintains contacts in a closed position without increasing the assembly size, reduces arcing, and allows for more predictable and controlled contact mating, even with large transient pulses, using softer and more conductive materials for the pads.
Implementation Method 1
Opposing electromagnetic forces are generated between the contact bridge and the conductive pads to resist electromagnetic repulsion forces generated between the current carrying contacts and the conductive pads
Implementation Method 2
When an electric current is passed through the coil assembly it generates a magnetic field that attracts the armature
Data Source
AI summary
A switch assembly adapted and a method for switching power to a circuit having a power source. The switch assembly includes current carrying contacts and a coupling member. The coupling member has conductive pads for engaging the current carrying contacts and a contact bridge extending between the conductive pads. An actuator assembly moves the coupling member between a closed position in which the conductive pads of the coupling member engage the current carrying contacts and an open position in which the conductive pads of the coupling member are disengaged from the current carrying contacts. Opposing electromagnetic forces are generated between the contact bridge and the conductive pads to resist electromagnetic repulsion forces generated between the current carrying contacts and the conductive pads as the actuator assembly approaches or is in the closed position.