PURPOSE: To miniaturize and lighten a device by integrally combining a high reduction gear ratio gear mechanism composed of a planet gear mechanism connected to one of the shaft of a motor and driving section, a terminal of which is mounted to the other of the shaft and into which a driver circuit is incorporated.

CONSTITUTION: A shaft 4 is projected to one side of a motor 1, and a high reduction gear ratio gear mechanism 2 consisting of a planet gear mechanism is bonded. The planet gear mechanism is formed by a sun external gear 6 having tooth number Z1=15 installed to the shaft 4, a carrier 7, three planet gears 9 having tooth number Z2=23, and a first sun internal gear 10 having tooth number Z3=60, fitted into the stepped section 1A of the case of the motor 1, and covered with a case 12. A second sun internal gear 14 having tooth number Z4=65 is engaged simultaneously with the sun internal gear 10 and the planet gear 9, and low-speed revolution at a reduction gear ratio 105 is output from a shaft 15. A driver circuit 18 connected to terminals J1-J6 at the other end of the shaft 4 is covered with a case 17, thus forming driving section 3. Accordingly, the motor 1, the high reduction gear ratio gear mechanism 2 and the driving section 3 are unified, and miniaturized and lightened. The title unit is suitable for an electrically-driven toy.