Water injection propulsion unit
AssigneeSanshin Kogyo Kabushiki Kaisha
InventorsHiroshi Tasaki, Kazumasa Ito, Makoto Toyohara
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Abstract
An arrangement is provided for variably adjusting the effective flow area along a region within a water injection propulsion unit. The invention is adapted to be embodied in a small watercraft of the type that is designed to be operated by a single rider sitting in straddle fashion on the watercraft. The flow area adjustments may be made in response to the value of a selected operating variable, or several variables, which may be measured during the operation of the watercraft. The invention allows attainment of optimum accelerability at low to medium speeds, and optimum accelerability and top speed at high speeds.
Claims33
A water injection propulsion unit for a jet powered watercraft comprising a water flow pathway defined by a water inlet portion for admitting water to said unit, an impeller portion for containing an impeller for pumping water, and a discharge portion for discharging water from said impeller portion back to the body of water in which the watercraft is operating, wherein said discharge portion is provided with an outlet at an extreme rearwardmost region thereof;
- said water injection propulsion unit further comprising an adjustment mechanism for variably adjusting the effective flow area of one of said portions to adjust the performance of said unit, wherein said adjustment mechanism is located upstream of said outlet throughout said adjustment mechanism's operative range of movement;
- and wherein said adjustment mechanism is movable outside of said water flow pathway.
Dependencies are inferred from the claim text.