Propeller for ship
AssigneeMitsui Engineering & Shipbuilding Co., Ltd.
InventorsTakeo Nojiri, Yasuo Irie
Life of this patent
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Abstract
In a propeller for use in a ship of the type comprising 4 or more even number blades, at least one of two adjacent blades is inclined forwardly or rearwardly or one inclined forwardly and the other rearwardly so as to make different the rake angles of the two blades. The pitch angle of the rearwardly inclined blade is made larger than that of the forwardly inclined blade. With this construction the mutual interference between adjacent blades is efficiently utilized to prevent decrease in the efficiency even when operating conditions and the diameter of the propeller vary.
Claims6
A propeller for use in a ship comprising a plurality of pairs of blades having axially overlapping roots anchored to a common hub, at least one of two adjacent blades being inclined forwardly or rearwardly so as to make different the rake angles of the two adjacent blades, and the pitch angle of a rearward blade being made larger than that of a forward blade, the difference in said rake angles being at least 10.degree. to locate the effective area of said rear blade in the accelerated flow from said forward blade.
Dependencies are inferred from the claim text.