WATERCRAFT HAVING LOW CAVITATION DRIVE
A watercraft comprises a hull which is bouyant in water, and a propulsion system coupled to the hull for for propelling the hull in the water. The propulsion system comprises a propulsion disc and at least one drive input coupled to the propulsion disc. The propulsion disc is rotatable by the drive input about an axis of rotation and comprises a cavitation-reducing ring and a plurality of paddles extending radially outwards from the cavitation-reducing ring, The cavitation-reducing ring is configured to reduce cavitation in the water during rotation of the propulsion disc.
This patent application claims the benefit of the filing date of U.S. patent application Ser. No. 60/851,321, entitled “Turbo Boat”, filed Oct. 13, 2006, and U.S. patent application Ser. No. 60/851,322, entitled “Stingray Boat”, filed Oct. 13, 2006.
FIELD OF THE INVENTIONThe invention described herein relates to a self-propelled watercraft. In particular, the invention relates to a pedal-powered watercraft.
BACKGROUND OF THE INVENTIONConventional pedal-powered watercraft are typically implemented as a kayak or a catamaran, and comprises a human-powered propulsion system. The propulsion system comprises a paddlewheel which is supported on a rotatable crankshaft. The paddlewheel creates cavitation in the water as the paddlewheel is rotated. As a result, the transfer of input pedal energy to watercraft movement is inefficient.
SUMMARY OF THE INVENTIONThe invention relates to a watercraft propulsion system that includes an inertial cavitation reduction mechanism.
In accordance with one aspect of the invention, there is provided a propulsion system that comprises a propulsion disc and a plurality of paddles. The propulsion disc has a central axis and comprising a cavitation-reducing ring. The paddles extend radially outwards from the cavitation-reducing ring. The cavitation-reducing ring is configured to reduce cavitation in water during rotation of the propulsion disc about the central axis.
In accordance with another aspect of the invention, there is provided a watercraft that comprises a hull which is bouyant in water, and a propulsion system coupled to the hull for propelling the hull in the water. The propulsion system comprises a propulsion disc and at least one drive input coupled to the propulsion disc. The propulsion disc is rotatable by the drive input about an axis of rotation and comprises a cavitation-reducing ring and a plurality of paddles extending radially outwards from the cavitation-reducing ring, The cavitation-reducing ring is configured to reduce cavitation in the water during rotation of the propulsion disc.
In one implementation, the propulsion disc has a pair of opposing sides, and comprises at least one aperture disposed radially outwards from the axis of rotation and extending axially between the opposing sides. The cavitation-reducing ring is disposed radially outwards from the at least one aperture, and comprises a pair of cylindrical walls each extending axially outwards from a respective one of the opposing sides.
Further, the propulsion disc also comprises a support ring that is disposed around a circumference of the disc. Each paddle includes an outer end and extends radially outwards from the cavitation-reducing ring and terminates at the respective outer end. The support ring is coupled to the paddles at the outer ends thereof.
The drive input may comprise comprises a pedal provided on a crankshaft, and the propulsion disc may comprise a keyed centre that is configured for receiving the crankshaft therein. The keyed centre is concident with the axis of rotation.
The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
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Preferably, the watercraft uses a dual independent drive system that allows for the left and right peddlers to pedal independently of each other and at their own pace. The dual independent drive system comprises a pair of turbo propulsion discs 4 and a pair of crankshafts 5. Each crankshaft 5 is supported by a pair of crankshaft bearings 32, 33, and is secured at one end to a corresponding propulsion disc 4.
Preferably the crankshaft bearings 32, 33 are tapered inwardly adjacent their open end to thereby retain the crankshafts 5 within the crankshaft bearings 32, 33. Further, preferably the crankshaft bearings 32, 33 are dimensioned relative to the recesses 23, 24 such that, when the crankshaft bearings 32, 33 are inserted into the recesses 23, 24, and the crankshafts 5 are installed into the crankshaft bearings 32, 33, the crankshafts 5 urge the crankshaft bearings 32, 33 slightly outwards to thereby retain the crankshaft bearings 32, 33 in the recesses 23, 24.
The propulsion disc 4 is best shown in
One variation of the propulsion disc is shown in
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The hood 2 also includes a tongue 53 at the rear portion thereof, and a pair of lock lips 52 disposed on opposite sides of the hood 2. When the hood 2 is rotated from the retracted position into the closed position (
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The bimini assembly 43 is depicted in
Claims
1. A watercraft comprising:
- a hull bouyant in water; and
- a propulsion system coupled to the hull for propelling the hull in the water, the propulsion system comprising a propulsion disc and at least one drive input coupled to the propulsion disc, the propulsion disc being rotatable by the drive input about an axis of rotation and comprises a cavitation-reducing ring and a plurality of paddles extending radially outwards from the cavitation-reducing ring, the cavitation-reducing ring being configured to reduce cavitation in the water during rotation of the propulsion disc.
2. The watercraft according to claim 1, wherein the paddles are substantially resilient.
3. The watercraft according to claim 1, wherein the propulsion disc has a pair of opposing sides, and comprises at least one aperture disposed radially outwards from the axis of rotation and extending axially between the opposing sides, and the cavitation-reducing ring is disposed radially outwards from the at least one aperture.
4. The watercraft according to claim 3, wherein the cavitation-reducing ring comprises a pair of cylindrical walls each extending axially outwards from a respective one of the opposing sides.
5. The watercraft according to claim 4, wherein the drive input comprises comprises a pedal provided on a crankshaft, and the propulsion disc comprises a keyed centre configured for receiving the crankshaft therein, the keyed centre being concident with the axis of rotation.
6. The watercraft according to claim 4, wherein the propulsion disc further comprises a support ring disposed around a circumference of the disc.
7. The watercraft according to claim 6, wherein each said paddle includes an outer end and extends radially outwards from the cavitation-reducing ring and terminates at the respective outer end, and the support ring is coupled to the paddles at the outer ends thereof.
8. A propulsion system for watercraft, the propulsion system comprising:
- a propulsion disc having a central axis and comprising a cavitation-reducing ring; and
- a plurality of paddles extending radially outwards from the cavitation-reducing ring, the cavitation-reducing ring being configured to reduce cavitation in water during rotation of the propulsion disc about the central axis.
9. The propulsion system according to claim 8, wherein the paddles are substantially resilient.
10. The propulsion system according to claim 8, wherein the propulsion disc has a pair of opposing sides, and comprises at least one aperture disposed radially outwards from the central axis and extending axially between the opposing sides, and the cavitation-reducing ring is disposed radially outwards from the at least one aperture.
11. The propulsion system according to claim 10, wherein the cavitation-reducing ring comprises a pair of cylindrical walls each extending axially outwards from a respective one of the opposing sides.
12. The propulsion system according to claim 11, wherein the propulsion disc comprises a keyed centre configured for receiving a crankshaft therein, the keyed centre being concident with the central axis.
13. The propulsion system according to claim 11, wherein the propulsion disc further comprises a support ring disposed around a circumference of the disc.
14. The propulsion system according to claim 13, wherein each said paddle includes an outer end and extends radially outwards from the cavitation-reducing ring and terminates at the respective outer end, and the support ring is coupled to the paddles at the outer ends thereof.
Type: Application
Filed: Oct 15, 2007
Publication Date: Jul 24, 2008
Inventor: David Lekhtman (Beaconsfield)
Application Number: 11/872,503