The utility model discloses a
vacuum arc-extinguishing chamber for a
circuit breaker, which comprises a
ceramic shell, a movable end cover plate arranged at the top of the
ceramic shell and a static end cover plate arranged at the bottom of the
ceramic shell, a movable conducting rod is slidably mounted in the middle of the movable end cover plate, one end of the movable conducting rod penetrates through the movable end cover plate and extends into the ceramic shell, and the other end of the movable conducting rod penetrates through the static end cover plate. The middle of the static end cover plate is fixedly connected with a static conducting rod, one end of the static conducting rod penetrates through the static end cover plate and extends into the ceramic shell, the adjacent ends of the dynamic conducting rod and the static conducting rod are provided with a
dynamic contact and a static contact respectively, the bottom of the static conducting rod is connected with a static conducting block, and the inner wall of the ceramic shell is provided with a main shielding cover. According to the utility model,
metal particles can be prevented from flying out of the upper and lower openings of the main shielding case through the material blocking cylinder, the cleaning ring and the auxiliary shielding case, and the
metal particles are prevented from splashing to the inner wall of the ceramic shell to influence the insulating property of the ceramic shell, so that the service life of the ceramic shell is prolonged.