110kV CT126-1 Circuit Breaker Spring Operating Mechanism

The 110kV CT126-1 porcelain column SF6 gas circuit breaker is the "safety gate" of high-voltage distribution networks. Its dedicated spring operated mechanism serves as the core power component, with "high-voltage adaptation, high reliability, and fast response" as the design core. Through customized energy storage and transmission systems, it accurately matches the opening and closing requirements of the circuit breaker, and is widely used in 110kV substations, cross regional transmission lines, and large industrial high-voltage distribution systems to ensure reliable on/off and fault isolation of high-voltage circuits.
1、 Core Working Principle: Energy Storage Transmission Logic in High Voltage Scenarios
1. Customized dual spring energy storage system
In response to the high operating power demand of 110kV circuit breakers (closing operation power ≥ 450J), the mechanism adopts a dual spring combination design of "main closing spring+auxiliary energy storage spring":
Main spring: Made of 60Si2MnA high-strength alloy spring steel with a diameter of 28mm, quenched at 1050 ℃ and tempered at 450 ℃, the tensile strength reaches 2100MPa, and can store 520J of energy at a maximum deformation of 35mm, providing core power for closing action;
Auxiliary spring: Made of φ 12mm 50CrVA spring steel, compressed synchronously with the main spring to assist in load sharing, reduce fatigue loss of the main spring, and extend the overall spring component life (≥ 15000 energy storage cycles).
The energy storage method supports dual modes of "electric+manual" and is suitable for emergency needs in high-voltage scenarios
Electric energy storage: Equipped with a 2.2kW three-phase asynchronous motor (AC380V, speed 1450r/min), the energy storage shaft is driven to rotate through three-stage helical gear reduction (reduction ratio 1:150), and the cam mechanism pushes the spring to compress. After the energy storage is completed, it is mechanically locked by the double pawl, and the travel switch triggers the motor to cut off power. The whole process takes ≤ 25s
Manual energy storage: In emergency situations, insert a Z-shaped extended rocker handle (650mm in length, designed with a labor-saving lever). When the rocker handle rotates at 20r/min, energy storage can be completed within ≤ 60 turns, meeting the emergency operation needs during power outages

2. Coordination of high-voltage opening and closing actions
The transmission connection between the mechanism and CT126-1 circuit breaker has been precisely calibrated to ensure precise operation in high-voltage scenarios
Closing process: After receiving the closing signal, the DC220V closing electromagnet (suction force ≥ 90N) pushes the release pin, and the double claws are synchronously released. The main spring instantly releases energy, and the main shaft of the circuit breaker is driven to rotate through the chrome molybdenum steel transmission connecting rod (φ 20mm, yield strength ≥ 800MPa), and the moving contact quickly closes. The closing time is ≤ 80ms, ensuring the rapid restoration of power supply to the 110kV line; At the same time, the opening spring synchronously stretches and stores energy, and the pre tightening force can be fine tuned within the range of 50-80N by adjusting the nut, adapting to the opening speed requirements of different arc extinguishing chambers.
Opening process: When the system detects faults such as short circuit (short circuit current ≤ 40kA), overload, etc., the opening electromagnet (or manual opening handle) will act, the opening lock will release, the opening spring will release energy, and the transmission mechanism will drive the moving contact to open. The opening time is ≤ 30ms, and it will cooperate with the arc extinguishing chamber of the circuit breaker to quickly cut off the high-voltage arc, avoiding the expansion of the fault. The opening rebound amount is ≤ 2mm, which meets the requirements of GB/T 1984-2014 "High Voltage AC Circuit Breaker" standard.