PROPULSION UNIT

摘要

PROBLEM TO BE SOLVED: To provide a propulsion unit which includes a rudder plate with a valve and sufficiently improves the propulsion efficiency of a ship with an easy structure.SOLUTION: A propulsion unit 1 includes: a rudder plate 21 which is provided at the rear side of a propeller 11 so as to steer a hull; a valve 22 which is provided at the rudder plate facing a propeller boss; and a cover member 12 which is provided at the propeller boss 14 and covers a front end surface of the valve 22 expanding a diameter toward the rear side of the propeller. The cover member is curved into a dome shape so as to form a substantially fusiform surface with the valve.