Propulsion device with conditioned inertia

Claim 1

Hydrojet propelling device including: a pump section comprising an elongated hollow housing with an inlet opening at one end and an outlet opening at the opposite end said housing containing at least a vaned rotor member in which a peripheral annular diverging passageway is defined between the inlet opening end and the outlet opening end through which water flow is associated, said rotor being keyed on a driving shaft; and, a discharge section comprising a stationary cup shaped wall projecting from the outlet opening of the pump section, said wall having a concave face curving oppositely to divergence of a surface forming the outer passageway of the pump section, this face having a variable curvature which is substantially tangent to the flow exhausted at the outlet opening of the pump section and substantially parallel to a straight direction along an axis of elongation at its free end, this concave face being provided with curved vanes having smooth curvatures in the axial direction providing arcuate surface portions whereby the flow exhausting from the pump section is divided in a plurality of water jets progressively and smoothly straightened from their diverging trajectory to a trajectory substantially parallel to said straight direction, said vanes being constituted by internal surfaces of tubes extending along said cup shaped wall.