To suppress a production cost and a power consumption energy to a lower level.

A disk part 31b vertical relative to a rotating shaft is formed on an input shaft 31, and a frictional surface for clutch 31c is formed on the output side of the vertical disk part 31b. A coil assembly 36 is fixed to the input side of a case 35 and a projected part 35a is provided on the output side to form a frictional surface for brake 39. A hub 40 is fixed to an output shaft 33, and an armature for clutch 42 and an armature for brake 44 are fitted to the output shaft 33 opposedly to the frictional surface for clutch 31c and the frictional surface for brake 39, respectively, so as to be displaceable in the axial direction. Both armatures are connected to each other with stepped bolts 45, and energized to the output side by a coiled spring 46. While a coil is energized, the armature for clutch 42 is attracted to the frictional surface for clutch 31c to transmit the rotation of the input shaft 31 to the output shaft 33. When the coil is not energized, the armature for brake 44 is brought into contact with the frictional surface for brake 39 to apply a brake to the rotation of the output shaft 33.