Three-jaw chuck mechanism for revolving body cover-shaped part

The utility model relates to the technical field of three-jaw chuck structures, in particular to a three-jaw chuck mechanism for a revolving body cover-shaped part. The three-jaw chuck is used for clamping a rotary body cover-shaped part body, a plurality of protruding ribs distributed in a circumferential array mode are arranged on the outer circumferential face of the rotary body cover-shaped part body, the three-jaw chuck is characterized by comprising a three-jaw chuck body, the three-jaw chuck body comprises three clamping petals, the three clamping petals are each provided with an arc-shaped limiting part, and the arc-shaped limiting parts are arranged on the three clamping petals. A limiting groove matched with the shape of the revolving body cover-shaped part body is formed among the arc-shaped limiting parts of the three clamping petals, and the radian of the limiting groove is the same as that of the convex rib; a plurality of arc-shaped grooves distributed in a circumferential array are formed in t