Variable Thickness Contactor for High Current Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Switching devices, such as those used for smart metering or power control, face issues with high short circuit currents causing sparking and damage due to inadequate contact pressure and electromagnetic repulsion, leading to potential hazards and poor connections.
Innovation Solution
A switching device with a contactor comprising a variable thickness design, featuring a relatively thick and thin portion integrally formed with a transition portion for smooth load transfer, and an actuator system that balances forces to prevent torsional distortions, ensuring reliable connection and disconnection under high current conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contactor uses a standard uniform thickness design, then the manufacturing is simple, but the contact pressure is insufficient under high current conditions causing poor connections
Solution Approach 1:
The contactor member is designed with variable thickness, having a first portion with a first thickness and a second portion with a second thickness that is greater than the first thickness. This local variation in geometry allows the contactor to provide adequate contact pressure at the contact interface while maintaining structural integrity, directly resolving the contradiction between connection reliability and manufacturing simplicity.
2Reliability
If the actuator provides high contact pressure to maintain connection, then the connection reliability improves, but the contacts may be welded together by current passing therethrough
Solution Approach 1:
The variable thickness design changes the mechanical parameters of the contactor member, creating an optimal balance between contact pressure and heat dissipation. The thicker second portion provides structural support and heat sinking capability, while the thinner first portion allows sufficient contact pressure, preventing both poor connections and contact welding under high current conditions.
3Ease of manufacture
If the contactor member has uniform thickness, then the manufacturing is easier, but electromagnetic repulsion forces cause blade separation and sparking under high currents
Solution Approach 1:
By implementing variable thickness in the contactor member with a thicker second portion and a thinner first portion, the design locally optimizes the structure to resist electromagnetic repulsion forces at the contact interface while maintaining manufacturability through a straightforward geometrical variation.
4Weight of moving object
If the contactor member is made thinner to reduce weight, then the actuation force required decreases, but the mechanical strength and contact pressure capability are reduced
Solution Approach 1:
The variable thickness design concentrates the material where it is most needed - the thicker second portion provides the mechanical strength and contact pressure capability, while the thinner first portion reduces weight and allows easier actuation, optimally balancing these conflicting requirements.
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 a reliable and safe switching mechanism capable of handling high currents and short circuit loads, preventing welding of contacts and reducing mechanical stress, thus enhancing the device's durability and operational safety.
Implementation Method 1
The actuator can be activated, such as by pulsing the solenoid coil, to provide a force sufficient to overcome an attractive force between the contacts
Implementation Method 2
Electromagnetic repulsion between the moving blade and the bus-bar, such as due to Lorenz forces, may force the moving blade away from the bus-bar
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A switching device (10) comprising a contactor (14) and an actuator (12). The contactor (14) comprises at least a first contactor member (16) and a second contactor member (18). The actuator (12) is configured to actuate the contactor (14). At least one of the contactor members (16, 18) comprises a varying or variable thickness along its length such that the at least one of the contactor members (16, 18) comprises a relatively thick portion (26) and a relatively thin portion (20).