WO2007072185B1

WO2007072185B1 - A propulsion system for a watercraft

Info

Publication number: WO2007072185B1
Application number: PCT/IB2006/003712
Authority: WO
Inventors: Andrew Bruce Taylor
Original assignee: Stellenbosch Automotive Engine; Andrew Bruce Taylor
Priority date: 2005-12-20
Filing date: 2006-12-20
Publication date: 2007-11-29
Also published as: WO2007072185A2; WO2007072185A3

Abstract

A propulsion system (10) for a watercraft comprises a propeller (12), a drive (14) for driving the propeller, a mounting arrangement for mounting the propeller to the stern of the watercraft and a trim hydrofoil 18 which is disposed at a level lower than the propeller. The system (10) includes a steering sub-system (22) which includes a pair of spaced opposed rudders (24.1 and 24.2) which are located at opposite sides of the propeller (12). The sub-system includes a shroud (26) which extends over the propeller (12) between the rudders. The shroud is pivotally mounted to a mounting plate (19) forming part of the mounting arrangement, in an arrangement permitting pivoting of the steering sub-system and thereby the rudders about a vertical pivot axis to facilitate steering and also tilting forward Iy and rearward Iy to thereby alter the angle of attack of the hydrofoil (18).

Claims

AMENDED CLAIMS [received by the International Bureau on 14 September 2007 (14.09.07)]CLAIMS

1. A propulsion system for a watercraft, including:

propulsion means in the form of a surface-piercing propeller having an upper side and a lower side, which is operable to propel the watercraft along a body of water;

drive means for driving the propulsion means;

propulsion mounting means for mounting the propulsion means at the stern of the watercraft;

a steering sub-system which is mountable to the propulsion mounting means and which includes steering means for altering the direction of travel of the watercraft;

a trim hydrofoil which is disposed at a level operatively lower than the upper side of the propulsion means and which is integrated with the steering means; and

an integrated steering and trim control sub-system for tilting the steering means in a vertical plane for altering the angle of attack of the trim hydrofoil and for pivoting the steering means from side to side thereby to interfere with water moving relative to the watercraft for altering the direction of travel of the watercraft.

2. The propulsion systems as claimed in claim 1 , wherein the trim hydrofoil is disposed of aft of the propulsion means.

3. The propulsion system as claimed in claim 1 , wherein the trim hydrofoil is disposed fore of the propulsion means.

4. The propulsion system as claimed in claim 3, wherein the trim hydrofoil is disposed below the axis of rotation of the propeller.

5. The propulsion system as claimed in claim 4, which includes at least one auxiliary trim hydrofoil which is disposed aft of the propeller operatively above the axis of rotation of the propeller.

6. The propulsion system as claimed in claim 5, wherein the auxiliary trim hydrofoil is disposed at a height between the axis of rotation of the propeller and an upper tip of the propeller.

7. The propulsion system as claimed in any one of claims 1 to 6, wherein the steering means includes at least one rudder and steering mounting means for mounting the rudder to the propulsion mounting means, and rudder control means for controlling the movement of the rudder.

8. The propulsion system as claimed in claim 7, wherein the steering means includes a pair of spaced, opposed rudders which are each located at a different one of the opposite sides of the propeller.

9. The propulsion system as claimed in claim 8, wherein the trim hydrofoil is mounted to and extends between the rudders.

10. The propulsion system as claimed in claim 9, wherein the auxiliary trim hydrofoil is mounted to and extends between the rudders.

11. The propulsion system as claimed in any one of claims 8 to 10, which includes at least one additional auxiliary trim hydrofoil which is mounted to and extends laterally outwardly from one of the rudders.

12. The propulsion system as claimed in claim 11 , which includes two additional auxiliary trim hydrofoils wherein each additional auxiliary trim hydrofoil extends laterally outwardly from a different one of the rudders.

13. The propulsion system as claimed in any one of claims 8 to 12, wherein the steering sub-system includes a shroud which is disposed above the propeller and which extends between the rudders.

14. The propulsion system as claimed in claim 13, wherein the shroud is in the form of a convexly curved panel.

15. The propulsion system as claimed in claim 14, wherein the steering mounting means is hingedly mounted to the shroud, thereby permitting hinged displacement of the shroud and thereby the rudders relative to the watercraft.

16. The propulsion system as claimed in claim 15, wherein the steering mounting means is pivotally connected to the shroud in an arrangement permitting pivotal displacement of the shroud about a pivot axis, the control means being operable to control pivotal displacement of the shroud and thereby the rudders, in use

17. A watercraft having the propulsion system as claimed in any one of claims 1 to 16, mounted to the stern thereof.

AMENDED SHEET (ARTICLE 19)