An output shaft to which the rotational force of a motor is transferred is housed in a case. One end side of the output shaft protrudes from a side surface of the case. A pinion gear is fixed to one end side of the output shaft. Teeth that mesh with the pinion gear are formed on the outer circumferential surface of cables. Cable guide surfaces for guiding the cables to mesh with the pinion gear are provided on the side surface of the case.