| 摘要 |
Disclosed herein is a ship rudder (4) disposed behind a propeller (2) at a stern of a ship (1) to control a movement direction of the ship. The rudder includes a middle blade (4a) located around an axis of the propeller and upper and lower blades (4b, 4c) located at upper and lower sides of the middle blade. The middle blade has a leading edge part having a bilaterally symmetrical shape with respect to a plane passing through the axis of the propeller and a perpendicular centerline of the rudder. The upper blade (4b) has a leading edge part twisted with respect to the plane passing through the axis of the propeller and the perpendicular centerline of the rudder to be biased in a reverse rotational direction of the propeller. The lower blade (4c) has a leading edge part twisted with respect to the plane passing through the axis of the propeller and the perpendicular centerline of the rudder to be biased in a forward rotational direction of the propeller. The leading edge part of the middle blade does not form a step, with respect to the leading edge parts of the upper and lower blades, at sides of the rudder in twisted directions of the upper and lower blades, but forms steps, where the leading edge part of the middle blade meets the leading edge parts of the upper and lower blades, at sides of the rudder in directions opposite to the twisted directions of the upper and lower blades, respectively. |
