STERN STRUCTURE FOR SHIP

PURPOSE:To reduce the hull resistance, improve the propulsion efficiency, and decrease oscillation by setting the flowing direction of the seawater induced by a pump from an outlet port provided on the external surface of a bossing that supports a propeller shaft to an inlet port, in the direction opposite to the rotation of the propeller. CONSTITUTION:When a propeller is turned in A direction and a seawater pump 12 is actuated at navigation, the seawater is sucked from respective inlet ports 3 and 4 through a suction pipe 9 and a connection pipe 11 and then ejected from outlet ports 5 and 6 through an ejecting recessed section 8 by the pump 12. Consequently, the flow of the seawater in the B direction is generated toward the inlet ports 3 and 4 from the outlet ports 5 and 6 and a seawater stream is advanced toward the propeller by the effect of the flow while it is turning in direction B opposite to the direction A of propeller rotation. As a result, the thrust of the propeller is improved and the propulsion efficiency is increased. In addition, since vortexes are collected on the surface of the propeller, the oscillation of the hull resulting from the propeller is reduced and cavitation and the generation of corrosion resulting from the cavitation can be prevented.