Air-blowing tripping mechanism and molded case circuit breaker

An air-blowing tripping mechanism, comprising a housing and a push rod rotationally connected to the housing, the housing is provided with a sealing cavity provided with an air-blowing channel, the air-blowing channel is blocked by an insulating partition plate, and a gas is able to blow the insulating partition plate to move, so as to enter into the sealing cavity;

• wherein the push rod comprises a rotating arm and a reset arm which are integrally arranged;
• the rotating arm is rotationally connected and a rotational joint of the rotating arm is on one side of the sealing cavity;
• a rotating center which is rotatably connected to the housing is provided in a middle of the rotating arm, one end of the rotating arm is provided with an operating portion opposite to an operating mechanism of a circuit breaker, and another end of the rotating arm is provided with an air-blowing end;
• the air-blowing end extends into the sealing cavity, is located on one side of the insulating partition plate and can drive the rotating arm to rotate under an action of the gas;
• and the reset arm, which is elastic, is disposed on one side of the rotating arm and used for driving the push rod to reset;
• an opening through which the air-blowing end extends is formed on one side of the sealing cavity;
• the air-blowing end extends into the sealing cavity through the opening;
• a sealing portion is disposed between the rotating center and the air-blowing end, a sealing protrusion is disposed at the opening, a matching groove is correspondingly formed in a sidewall between the sealing portion and the air-blowing end;
• and during a swing course of the push rod, the matching groove is in sliding fit with the sealing protrusion, the sealing portion blocks the opening to keep the sealing cavity in a sealed state;
• a length of an arc-shaped surface of the sealing portion that blocks the opening is greater than an opening length of the opening, and during the swing course of the push rod, the sealing portion always blocks the opening, or always blocks a side of the opening close to the air-blowing channel.