To provide a device capable of withstanding the overhung load of an output shaft and reducing the number of part items as a whole without increasing the size thereof by reducing the number of the points requiring a gap adjustment by shims.

In a yoke 36 fixed to an axial intermediate position inside a case 35, a brake coil 38 and a clutch coil 37 are assembled on the input and output sides thereof, respectively. To an output shaft 33 supported by a first bearing 39a disposed in the case 35 and a second bearing 39b disposed on the inner periphery of the yoke 36, a brake hub 40 and a rotor 41 are fixed on the output and input sides thereof, respectively. A brake armature 40a is installed on the brake hub 40 opposedly to the brake frictional surface 38a of the yoke 36. An input shaft 31 is fitted to the input side of the output shaft 33 through a third bearing 39c, and a clutch armature 31a is installed on a rotor opposedly to a clutch frictional surface 41a.