EDDY-CURRENT BRAKE

Since a speed reducer includes: a brake disk that is fixed to a rotation shaft of a vehicle; permanent magnets that are disposed not only oppositely relative to a principal surface of the brake disk but also circumferentially in such a manner that each magnet is magnetized in reverse polarity to adjacent ones; a rotational member that retains the permanent magnets, has a switch brake disk, and is rotatably supported by the rotation shaft; a switch brake caliper that has brake pads sandwiching the switch brake disk therebetween, and is fixed to an irrotational portion of the vehicle; and an electric linear actuator that causes the brake pads to be linearly driven by converting rotational motion of the electric motor into linear motion, the speed reducer can realize a reduction in size, and thus can be installed even in a small- to mid-size vehicle not especially equipped with a compressed air tank or the like.