To achieve a turning actuator equipped with a small-sized electric motor and a small-sized speed reducer ensuring a large deceleration ratio, and greatly decreased in size; and to ensure turning torque and turning speed necessary and sufficient for the turning action of a propulsion unit.
The turning actuator 11 has the speed reducer 13 provided with a pinion 17 meshed with a turning gear, and the electric motor 12 rotation-driving the speed reducer 13. The speed reducer 13 has a case 15 provided with an inner tooth 20, an outer tooth gear 26 meshed with the inner tooth 20, a crank shaft 24 eccentrically rotating the outer tooth gear 26, and an output portion 25 roratably holding the crank shaft 24 and attached with the pinion 17. The rated engine speed of the electric motor 12 is set to be 1,000-3,000 RPM. A speed ratio in the speed reducer 13 is set to be 50-100, and a speed ratio of the pinion 17 to the turning gear is set to be 10-20.
NAKAO HIROSHI
FUKUI TAKEHIKO
SASAKI YASUHIRO
