Patent ID: 6086436
Filing Date: 2000-07-11
Classification: B63H

Abstract:
A water jet propulsion apparatus for a ship, comprising:a pump frame having an upper opening, a lower opening and a water passage communicating between said upper and said lower openings, said pump frame joined to a bottom of a ship with said lower opening adapted to be opened into water adjacent to a stern of said ship;a pump casing having an introduction portion and a discharge portion, said pump casing oriented erect above said pump frame, with said introduction portion in communication with said upper opening;an impeller on a main shaft, said shaft orientated erect in a portion of said pump casing and adapted arranged to be rotated, rotation of said the impeller sucking water from below said bottom of said ship through said lower opening so as to pressurize the water;a discharge pipe having a first end connected to said discharge portion of said pump casing, said discharge pipe jetting out water pressurized by said impeller from a second end of said discharge pipe to a position behind said stern;said impeller includes a plurality of blades that are spirally joined to said main shaft, said blades having outer ends disposed adjacent to an inner surface of said pump casing and said blades having outer leading ends disposed adjacent to said introduction portion extending downwards to a position adjacent to a water passage of the pump frame; anda plurality of long and twisted guide blades projecting over a bearing case and disposed more closely adjacent to said discharge portion than said blades of said impeller.