US 3,993,015 A · Hydraulic jet propulsion system

Abstract

An hydraulic propulsion system for watercraft involving the forming of a parallel-sided, open-ended inlet intake tunnel with a recessed intake screen at the rear of the craft, which tunnel directs the incoming water flow into a single or multi-stage cylindrical axial pump having multi-vaned matched impellers and straighteners for driving the flow into an unobstructed acceleration chamber which converges the flow according to the rule of minimal flow losses, and discharges it as a jet through a cylindrical opening with controls thereat to propel and steer the craft. The intake tunnel and the acceleration chamber may be formed of fiberglass, with the former being laminated or molded into the hull of the craft, and the overall system may be of simplified, light-weight, compact construction while producing at least 15% greater thrust than conventional propulsion systems, and much greater thrust than prior hydraulic jets, of comparable power, installed in the same craft.

Claims30

Dependent claims

In an hydraulic jet propulsion system for watercraft of the type comprising:

a. an intake section for directing incoming water from under the craft;
b. a pump section for receiving incoming water from said intake section and increasing the energy thereof;
and
c. a discharge section for accelerating and discharging the increased energy water as a jet;
the improvement comprising:
d. an intake passage within said intake section comprising:
i. two substantially vertical side walls having lower edges at the same level and substantially parallel to each other;
ii. an aftwardly inclined front wall laterally joined to said side walls, and having a lower front portion cooperating with the lower edges of said side walls to form a parallel-sided intake opening with an aftward open end;
and
iii. a rear edge member disposed above the level of and at the aftward open end of said intake opening, which member is joined to said sidewalls and cooperates with said side walls and said front wall to form a substantially cylindrical outlet opening to said pump section.

7 more elements

In an hydraulic jet propulsion system for watercraft the combination comprising:

an intake means for directing incoming water from under the craft, said intake means comprising:
i. means for defining an intake passage;
ii. means for defining in the underside of the craft a parallel-sided intake opening to said intake passage with an aftward open end;
and
iii. means disposed above said aftward open end for defining a cylindrical outlet opening from said intake passage;
b. a pump means for receiving incoming water from said intake section and increasing the energy thereof, said pump means comprising:
i. a cylindrical casing disposed aft of and in axial alignment with said cylindrical outlet opening;
ii. at least one set of straightener vanes fixed in said casing;
iii. at least one rotatable impeller disposed upstream of said straightener vanes;
and
iv. drive means for rotating said impeller;
and
c. a discharge means for accelerating and discharging the increased energy water as a jet, said discharge means comprising:
i. an annular casing disposed aft of and axially aligned with said cylindrical casing;
ii. means for defining an acceleration chamber with an aftwardly diminishing interior diameter within aid annular casing;
iii. an outlet end integral with said annular casing;
and
iv. means within said outlet end for defining a cylindrical opening at the exit of said acceleration chamber.

15 more elements

An hydraulic jet propulsion system for watercraft comprising:

a. an intake passage comprising:
i. two substantially vertical parallel sidwalls;
ii. an aftwardly inclined front wall with the lower portion of said front wall joining the lower edges of said side walls to form an intake opening;
and
iii. a rear edge member disposed at the transom of said watercraft above the level of said intake opening and joining with said side walls in such manner that said edge member, said front wall and said side walls form a cylindrical opening aft of said transom;
b. a pump assembly disposed at said outlet opening and comprising:
i. a cylindrical casing axially aligned with said cylindrical outlet opening;
ii. a plurality of straightener vanes mounted within said cylindrical casing;
iii. an impeller disposed upstream of said straightener vanes;
and
iv. drive means for mounting and rotating said impeller;
and
c. a discharge chamber disposed aft of said pump assembly comprising:
i. an acceleration chamber axially aligned with said cylindrical casing and formed of an annular wall of aftwardly diminishing cross-section;
and
ii. a cylindrical outlet end at the exit of said acceleration chamber.

13 more elements

Dependencies are inferred from the claim text.

Hydraulic jet propulsion system

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Hydraulic jet propulsion system

Life of this patent

Abstract

Claims30