| 摘要 |
PURPOSE: To decrease exhaust resistance by forming an exhaust passage on a first propeller device on the front side, and forming the outside diameter of a hub member of a second propeller device on the rear side smaller than the inside diameter of an outer hub member of the first propeller device in a ship propulsion device provided with two propeller devices on the front and rear sides. CONSTITUTION: In a contra-rotating type ship propulsion device 10, an outer shaft 13 and an inner shaft 14 are respectively rotated in the reverse directions by the rotation of an output shaft 22 of an engine through vertical bevel gears 20, 21, and propeller devices 11, 12 are also rotated in the reverse directions, so as to generate thrust in the advancing direction. At this time, exhaust gas from the engine is discharged to the outside through exhaust passages 3, 4 formed on a lower case 1c and the propeller device 11. Since the outside diameter of a hub member 12a of the propeller device 12 is formed smaller than the inside diameter of an outer hub member 11b, exhaust gas is allowed to flow along propeller blades 12b of the propeller device 12, and resistance of water in the propeller device 12 is drastically decreased. |
