Water jet propulsion unit with counter-rotating impellers
AssigneeBombardier Motor Corporation of America
InventorClarence E. Blanchard
Life of this patent
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Abstract
A water jet apparatus with counter-rotating impellers for propelling a boat. The impellers are coupled by an assembly comprising an impeller shaft secured to a first impeller and a gear train coupling the impeller shaft to a second impeller for counter-rotation. Preferably the gear train comprises one beveled gear secured to the impeller shaft, another beveled gear secured to the second impeller, and a beveled pinion meshed with the first and second beveled gears. The counter-rotating impellers can be driven by a drive shaft coupled to the first impeller for boats having an inboard motor or by a drive shaft coupled to the pinion for boats having an outboard motor.
Claims37
A water jet apparatus comprising:
- a flow-through housing;
- a hub installed inside said housing;
- a shaft extending inside said hub and rotatable relative to said hub;
- a first impeller secured to said shaft;
- a second impeller rotatable relative to said shaft and relative to said hub, said first and second impellers being coaxial;
- and
- a gear train arranged to cause said second impeller to rotate in a first direction in response to rotation of said shaft in a second direction opposite to said first direction, wherein said gear train is located to the rear of a rearmost one of said first and second impellers.
A water jet apparatus comprising:
- a duct comprising a nozzle having an outlet;
- a hub installed inside said duct and arranged to provide a generally annular flow region between said hub and said duct which is in flow communication with said nozzle outlet;
- a first structure rotatable relative to said hub about an axis, said first structure comprising a first plurality of impeller blades, a first multiplicity of gear teeth, and a shaft which is coaxial with said axis and extends between said first plurality of impeller blades and said first multiplicity of gear teeth;
- a second structure rotatable relative to said hub and relative to said first structure about said axis, said second structure comprising a second plurality of impeller blades and a second multiplicity of gear teeth;
- and
- a mechanism for coupling said first multiplicity of gear teeth to said second multiplicity of gear teeth to cause said second plurality of impeller blades to rotate in a first direction in response to rotation of said first structure in a second direction opposite to said first direction,
- wherein said first and second multiplicities of gear teeth are housed inside said hub and are located to the rear of said first and second pluralities of impeller blades.
A water jet apparatus comprising:
- a duct having an inlet and an outlet;
- first and second impellers rotatably installed within said duct;
- first drive means for rotating said first impeller in a first direction;
- and
- second drive means for rotating said second impeller in a second direction opposite to said first direction concurrently with rotation of said first impeller in said first direction,
- wherein at least a portion of said second drive means is located to the rear of a rearmost one of said first and second impellers.
A water jet apparatus comprising:
- a duct having an inlet and an outlet;
- first and second impellers rotatably installed within said duct;
- and
- an assembly for rotating said first and second impellers in opposite directions, wherein said assembly extends to the rear of a rearmost one of said first and second impellers.
A water jet propulsion unit comprising:
- a duct having an inlet and an outlet;
- a first structure which is rotatably installed within said duct for rotation about an axis, said first structure comprising a first multiplicity of impeller blades, a shaft extending to the rear of said first multiplicity of impeller blades, and a first gear secured to an end of said shaft and located to the rear of said first multiplicity of impeller blades;
- a second structure which is rotatably installed within said duct for rotation about said axis, said second structure comprising a second multiplicity of impeller blades located to the rear of said first multiplicity of impeller blades, and a second gear located to the rear of said second multiplicity of impeller blades, but forward of said first gear;
- and
- a mechanism for coupling said first gear to said second gear in a manner which causes said second structure to rotate in a direction opposite to said first structure.
Dependencies are inferred from the claim text.