The utility model discloses a self -sustaining formula arresting gear, the device include the casing, one side opening of casing is used for covering this open -ended apron in the opening part installation, sets up communicating rotary axocoel and slide chamber in the casing, the outer revolving axle of casing inserts foretell revolving axle intracavity can be at free rotation wherein, foretell slide chamber expert to the opening part of casing can respectively be provided with a spring cavity in the both sides of slide at gliding slide wherein in the setting of slide intracavity. The utility model discloses a self -sustaining formula arresting gear, a built -in spring's spring cavity respectively is provided with in the both sides of slide, when rotatory extremely its bulge of cam supports tight cam groove, in the spring cavity under spring force's the effect, protruding contacting with the revolving axle on the slide sliding -tongue makes it unable rotatory, realize the braking of revolving axle, protruding the contacting with the revolving axle that spring force can remain throughout on the slide sliding -tongue this moment makes it unable rotatory, thereby realize not consuming energy self -sustaining braking state.