To store a brake shoe 44 in a space formed by a brake base part 42 and a brake drum 46, by mounting a rear wheel 29 directly in the brake drum 46, providing a cooling fin 58 for heat radiation in an external peripheral surface of the brake drum 46, mounting a seal member 47 in an opening edge of the brake drum 46, and mounting an L-shaped plate 54 for attaching lips 64, 65 of this seal member 47 in the brake base part 42 mounted in a side of a car body 11.

As compared with in the past, a number of parts can be decreased, as compared with mounting of a wheel, for instance, in a hub separate from a drum, a car width can be lessened, and a drum brake is received in the wheel, weight of a vehicle can be lightened. Further, heat radiation of the drum brake can be improved.