Structural Design Of Sf6 Circuit Breaker Operating Mechanism

The sf6 circuit breaker operating mechanism mainly adopts three forms: hydraulic, pneumatic and spring. In the field of ultra-high voltage, hydraulic and pneumatic mechanisms are widely used due to their strong power output, especially in devices above 550kV. Medium-voltage circuit breakers are generally equipped with spring mechanisms, which can significantly reduce the maintenance costs of sf6 circuit breaker spring mechanism while ensuring operating speed. The coordination between the power element and the transmission rod directly determines the contact opening and closing speed, thus affecting the arc extinguishing efficiency.

The internal insulation design of the circuit breaker employs a three-dimensional protection system. The configuration of the porcelain bushing and insulating rod forms the first barrier in the electrical path. The support porcelain bushing is filled with SF6 gas at rated pressure; this sealed gas-filled structure provides reliable insulation protection under high-voltage environments. The opening distance between the moving and stationary contacts is precisely controlled by the mechanism during the opening process. The rated opening distance range of the contacts and the effective length of the insulating rod form a coordinated insulation system.