Engine exhaust apparatus for water-jet propulsion boat
A propulsion apparatus is described for a water jet propulsion boat having a hull, a water jet pump casing with the hull, and an impeller in the pump casing driven by an engine in the hull, the propulsion apparatus comprising: means in the pump casing defining a converging passage for increasing water flow velocity and having a smaller diameter section within which water jet pressure is reduced due to the increase in velocity; a hollow impeller shaft defining an exhaust passage within an inner wall of the impeller shaft. The exhaust passage is communicated at a forward end portion of the impeller shaft with an exhaust port of the engine; means connecting the impeller to the impeller shaft: an exhaust outlet communicating with the exhaust passage formed in the impeller shaft and located rearward of the impeller and within the smaller diameter section of the pump casing. This discharges exhaust into a water jet portion of higher velocity and reduced pressure within the section, that exhaust outlet communicating at a rear end surface of the impeller shaft, and a centrifugally operated stop valve for the outlet operated by the impeller shaft.
- Assignee:
- Kawasaki Jukogyo Kabushiki Kaisha, Kobe
- Patent Number(s):
- US 4631032
- OSTI ID:
- 6973922
- Resource Relation:
- Patent File Date: Filed date 22 Jan 1985
- Country of Publication:
- United States
- Language:
- English
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