A drum brake for braking a wheel disposed on the inside in the radial direction
of an electric motor. The drum of the drum brake and an electric motor are disposed
separate from each other, and thus wear powders of a brake shoe do not adhere to
a permanent magnet of the electric motor. As a result, the wear powders do not
adversely influence the performance of the electric motor, and the performance
of the electric motor is maintained. The electric motor and the drum brake are
disposed concentrically, so that the width of the wheel is reduced. Thus, a small
and compact wheel is realized.
