Circuit breaker and quick tripping device thereof

A tripping device of a circuit breaker, comprising an operating mechanism and a contact system, wherein the contact system comprises a moving contact mechanism and a static contact which are used cooperatively;

• the moving contact mechanism comprises a contact support rotatably disposed around a first center, and a moving contact disposed on the contact support and capable of rotating relative to the contact support;
• the moving contact mechanism further comprises a contact spring, and two ends of the contact spring are connected with the moving contact and the contact support respectively;
• the tripping device further comprises a first transmission structure rotatably disposed on the contact support and being in driving fit with the operating mechanism;
• the first transmission structure is in driving fit with the contact spring and rotates along with the contact spring;
• when a short-circuiting current flows through the contact system, the moving contact is repelled by an electric repulsion force between the moving contact and the static contact, so that the moving contact rotates relative to the contact support;
• the moving contact drives the first transmission structure to rotate through the contact spring;
• and the first transmission structure drives the operating mechanism to trip.