Drum type single-pin wedge brake

The utility model discloses a drum type single-pin wedge brake which comprises a brake bottom plate assembly, a pair of brake shoe and friction plate assemblies, a reset spring, a limiting spring and an expander. The pair of brake shoe and friction plate assemblies is symmetrically arranged on the two sides of the brake bottom plate assembly. An expander is fixed on an inclined mounting surface at the top of the brake bottom plate assembly, a wedge block assembly with a spring on the expander is mounted in a wedge type air chamber, and toothed flange surfaces of two adjusting screw rods of the expander are respectively in contact with the inner sides of the pair of brake shoe and friction plate assemblies; the tops of the pair of brake shoe and friction plate assemblies are connected and fixed through reset springs, and the bottoms are connected and fixed through limiting springs. According to the structure, the brake performance is improved, the problem of return clamping stagnation of the brake shoes is eff