GB2467364A - A personal water craft or water scooter - Google Patents

Abstract

A personal watercraft or water scooter includes a hull 1, a motor, at least one water intake (8 and 9, Fig 2), two water outlets located between the bow and stern of the hull, at least one impeller (17, Fig 3) for pumping water from the water intake(s) to the water outlets and a displaceable thrust nozzle 6 and 7 provided at each water outlet for directing the outflow of water. Each displaceable thrust nozzle is rotatable through one hundred and eighty degrees (180°) and is independently controllable by position control means 4 for steering the craft. Each thrust nozzle may be rotated by means of a respective electric motor (12, Fig 3). The thrust nozzles may be located centrally of the hull and on opposite lateral sides of a central fore and aft axis, and are normally submerged when the craft is floating on water.

Description

A PERSONAL WATER CRAFT OR WATER SCOOTER

The present invention relates to a highly manoeuvrable personal leisure watercraft with an improved nozzle control and propulsion system.

Watercraft have been referred to previously as a jet-skis' and as marketed by Kawasaki.

According to the present embodiment there is defined a personal watercraft or water scooter including a hull, a motor, at least one water intake, two water outlets located between the bow and stern of the hull (front and rear of the hull), at least one impeller for pumping water from the water intake(s) to the water outlets, a displaceable thrust nozzle provided at each water outlet for directing the outflow of water and rotatable through one hundred and eighty degrees (1800) with each nozzle being independently controllable by position control means for steering the craft. Thus the direction of outflow of water from the impeller is controlled by positioning the respective nozzle, power driven rotational duct or other water jet directing means. Further preferred features are defined in the sub-claims 2 to 4 and described herein.

Preferably the craft has an improved hull design, twin independent thrust outlet nozzles an associated independent control systems. The craft is propelled and controlled by water thrust, from preferably two centrally positioned, power driven thrust outlet nozzles.

The outlet nozzles are preferably centrally positioned to allow manoeuvrability in any direction. The hull unlike other watercraft is smooth to contribute to manoeuvrability. The centrally positioned thrust nozzles allow axle rotation and greater lateral' control.

The thrust nozzles are each controlled independently by joystick/control levers, this arrangement allows a greater degree of manoeuvrability than with previous craft.

The thrust nozzles are under independent control to jointly allow multi-directional control of the craft. The port nozzle is controlled by the left hand of the driver and the starboard nozzle is controlled by the right hand of the driver.

Each nozzle will direct water under pressure from the impeller, this water driven by its impeller -(a water compressor) is directional through 180 degrees of rotational movement. This will allow the water to propel the craft forwards, sideways and reverse.

Preferably a control lever is pushed forward its relevant thrust nozzle rotates to the rear direction of the craft. In this position the thrust nozzle directs the water out towards the rear of the craft and as with Newton's third law For every action, there is an equal and opposite reaction'. The water expelled from the thrust nozzle propels the craft in opposite direction.

As a control lever is pulled back, its relevant thrust nozzle preferably rotates to the forward direction of the craft. In this position the thrust nozzle directs the water out towards the front of the craft.

The control and rotation of the nozzles can be from a stationary position or whilst the craft is in motion. This will allow the craft to new manoeuvres, stunts and competitive challenges.

A variable, adjustable, thrust nozzle rotation speed system is incorporated to allow training and a customisation with the craft.

The invention will be described further, by way of example, with reference to the accompanying drawings and diagrams, in which:-Figure 1 is a schematic elevation of a personal water craft with the following reference numerals identifying the following components:-1, Hull, 2, Control tower, 3, Instrument display, 4, Joystick lever, 5, Seating, 6,7, Thrust nozzles; Figure 2 is a schematic inverted plan of the main hull with the following reference numerals identifying the following components:- 8, Water intake starboard, 6, Thrust nozzle starboard, 10, Thrust nozzle inset area starboard, 1B, Hull, 11, Thrust nozzle inset area port, 7, Thrust nozzle port, 9, Water intake port; Figure 3 is a schematic partial transverse section illustrating a thrust housing with the following reference numerals identifying the following components:- 1A, Hull exterior, 12, Thrust nozzle motor and gear drive, 1 3, Thrust nozzle drive shaft, 14, Drive shaft bearing and seal, 6,7, Thrust nozzle, j 15, Water flow from thrust nozzle, 16, Impeller and thrust nozzle housing, 17, Impeller, 18, Impeller drive shaft seal and bearing, 19, Impeller drive shaft, 8,9, Water intake and water flow, 20, Pressurised water flow Figure 3A is a schematic inverted plan of the underside of a dish-shaped thrust nozzle 6,7; Figure 3B is an elevation of a thrust nozzle 6,7 looking thereinto via the outlet opening; Figure 3C is a plan of a thrust nozzle 6,7 from above looking into the dish-like shaped with drive shaft in the centre; and Figure 3D is an elevation of a thrust nozzle 6, 7 from the side of the outlet opening thereof; Figure 4 is a schematic illustration of the gearbox with the following reference numerals identifying the following components:- 21, Gearbox housing, 22, seal, 23, bearing, 24, bevel gear, 25, output' drive shaft', 26, input drive shaft Hull The craft has a hull 1 which is of similar dimensions and resembles a conventional personal leisure watercraft or water scooter, such as a Jet Ski" as marketed by Kawasaki, and is manufactured from fiberglass or other composite material.

The craft has a water tight upper section incorporating seating 5 and control tower 2 with handlebar carrying some controls.

The craft has an inner hull which houses the fuel tank, engine, battery, thrust nozzle control mechanism, electronic control systems (not shown).

The control tower 2 contains direction control levers 4, electronic LED displays showing fuel tank level, engine temperature, battery condition, power switch, nozzle position indicators, engine start and stop buttons, emergency engine stop safety system.

The underside of the hull is a smooth un-ribbed or none contoured profile, this is to allow 360 degree rotation of the craft and sideways manoeuvrability through minimised water resistance.

The hull 1 has two independent water intakes 8,9 below the water line, one for each impeller intake and two power driven water ducting outlets 6,7 -thrust nozzles' 6,7.

The hull 1 has two indented areas around and to protect the thrust nozzles 6,7.

The hull I has shaped protrusions positioned midway between front and rear of the craft and spaced to port and starboard and the protrusions accommodate the rotating thrust nozzles 6,7 below the water line.

Each protrusion will be shaped to contain the thrust nozzle 6,7 in the event of mechanical failure.

Steering thrust nozzles A unique property of the craft is that its steering or directional control is effected in the example via the two independently controlled thrust nozzles' 6,7.

The craft has two rotating thrust nozzles 6, 7 mounted to port and starboard, midway between the front and rear of the craft, below the waterline.

Each nozzle protrudes externally with a minimal profile to minimise drag resistance.

Each nozzle 6,7 is of a round, smooth dome shape with an opening for the pressurised water to exit.

The nozzle 6,7 is a power driven rotational duct, it controls the direction of pressure driving water which propel the craft in the desired direction.

Each thrust nozzle 6,7 is mounted on a load bearing rotating shaft 13.

The shaft 13 passes through a watertight seal mounted in the impeller housing, it is then passes through a bearing mount. The shaft is firmly attached to the hull by the bearing housing 12.

The shaft 13 is connected to an enclosed worm/spur' gear drive, the gear drive is a speed reduction mechanism that converts the high speed low torque rotation of an electric motor drive shaft into a high torque lever arm movement.

The gear drive 12 is driven by a twelve volt electric motor 12. the motor is power by the electronic control system. The electronic control system can under the control of the driver, activate the motor to rotate in a clockwise or counter clockwise direction as a response the position of the joystick lever 4.

When no power is applied to the motor it remains stationary.

The 12 volt motor 12 drives and rotates thrust nozzle drive shaft 13 and the attached thrust nozzle 15. The thrust nozzle directs the pressurised water to match the position selected by its handlebar control joystick 4.

Under control of the motor 12, the nozzle 6,7 can be controlled to rotate through one hundred and eighty degrees of horizontal rotation.

A transducer is attached to the shaft and the transducer converts the rotational movement of the shaft to control feedback voltage representing the position of the joystick 4.

Engine (not shown) The engine is a standard four-stroke internal combustion design.

The engine speed is controlled by a standard handlebar mounted trigger leaver.

The engine controls are mounted on the control tower.

Drive from engine is linked to a gearbox.

Gearbox A conventional drive shaft 26 from the engine is connected to a one into two tee' gearbox' 2.

The single input to the gearbox 24 is split into two output shafts 25 by a tee' gearbox 24.

The two output shafts 25,25' exit at ninety degrees to the input shaft.

The two drive shafts are then connected to the two individual water intake impellers 17,17.

Impeller 17 Each impeller 17 is provided in the form of a high speed rotating water compression propeller', the impeller 17 inducts water and "compresses" it to create thrust. The impeller 17 is contained in a watertight housing 16, the housing is an integral part of the hull. The impeller 17 is mounted on a drive shaft 19, the drive shaft is mounted on bearings 18 and has a water tight seal 18 at the point it passes through impeller housing.

The impeller housing is mounted in an enclosure over a grille protected intake in the hull.

The impeller housing 1A has a removable, re-sealable hatch to allow construction and maintenance.

The impeller 17 driven at high speed by the engine, compresses water as it inducted.

The impeller 17 is connected to the gearbox drive shaft 19 through a water proof seal 18 through the wall if the impeller housing.

The impeller drive shaft 19 is mounted on thrust load bearings 18 attached to the inner hull.

The water compressed by the impeller 17 is in an enclosed water tight housing and directed towards the steering thrust nozzle 15 in the same housing assembly.

Deflection baffle (not shown in Figs. 1 to 4) When the thrust nozzle 15,16 is in a neutral position water is ejected sideways from each nozzle allowing sideways movement of the craft.

A deflection baffle (not shown) can be manually lowered in front of the ejected water by a foot operated controlled peddle.

In the lowered position the water is deflected by the baffle equally forwards and backward.

In the lowered position the equally deflected water helps keep the craft in a station-keeping mode.

The amount of sideways movement or sideslip can be varied by the selected position of the thrust nozzle and the position of the baffle.

Independent and individually controlled baffles are associated to each port and starboard thrust nozzle The deflection baffle can be used during engine start-up, engine maintenance or in general use to enhance the craft manoeuvrability.

Joystick -control position The joystick/levers 4 are mounted on the craft immediately in front of the driver as with a conventional jet ski. One joystick for each thrust nozzle.

The joystick levers 4 are to be of a firm and strong construction as this will be the main support on point for the driver The joystick levers 4 are attached to the control tower 3 on bearing mounted shaft.

Each joystick 4 controls its individual thrust nozzle 6,7 located approximately below the lever in the inner hull.

When at rest, the joystick 4 self-centres by a spring loaded mechanism, the thrust nozzles 6,7 then direct the water side ways directly to port or starboard.

Encased in a waterproof housing within the control tower are transducers attached to the joystick lever shaft.

The transducer is a variable voltage output device, it converts the movement of the joystick lever into an electrical voltage representing the position of the joystick.

As the lever 4 is pushed forward the voltage changes to match the degree of movement of the lever.

The transducer signal is connected the main electronic control circuit by insulated wire.

The varying electric voltage signal is processed by the electronic control system to control the position of the individual thrust nozzle.

As the joystick lever is pushed forward the thrust nozzle is rotated to direct the opening of the thrust nozzle to face the rear of the craft, in this position the thrust is expelled out from the rear direction.

As the joystick lever 4 is pulled back the thrust nozzle 6,7 is rotated to direct the opening of the thrust nozzle to face the front of the craft, in this position the thrust is expelled out from the forward direction.

Electronic Control System (ecs The ecs incorporates two identical circuits, one each for the port and starboard thrusters.

The ecs is powered by the onboard l2volt battery.

The ecs is contained in a waterproof housing within the inner hull.

The ecs is designed to control the direction of the thrust nozzles.

It is an electronic interface between the driver controlled joystick levers and the position of the thrust nozzles.

Inputs are from the hand operated joystick lever transducers and the feedback signal from the thrust nozzle position transducers.

The output of the ecs controls the position of the thrust nozzle through the power switching transistors.

The electronic control system consists of - 1, A differential operational amplifier.

A differential operational amplifier in the present configuration has two inputs and one output.

Input one is the joystick control signal is from the manually controlled joystick lever transducer.

Input two is the thrust position feedback signal is generated by the transducer mounted on the thrust nozzle drive shaft.

The varying voltage control signals from the joystick lever and the thruster position feedback transducers are connected to the differential operational amplifier (op-amp) inputs.

The differential operational amplifier, compares two input control voltages and outputs a changing voltage if the inputs are at different levels.

The output of the differential operational amplifier is a voltage that changes in response to the changes of the input voltages.

2, Two comparator operational amplifiers.

A comparator has two inputs, one input is connected at a fixed voltage, the other input is connected the output of the differential op-amp. The comparator compares the fixed voltage input with the varying voltage input and changes its output voltage accordingly.

The comparators are configured as Schmitt triggers. This configuration ensures rapid and clean switching from high (+ supply voltage) to low (0 supply voltage) and vice versa.

This voltage change is used to switch the required power transistors.

One comparator is configured to switch at above a pre-set level the other comparator is configured to switch below a pre-set level, in response to the changing voltage from the differential op-amp The present design allows only one comparator to be switched on at any time.

3, Bi-directional power transistor switches module.

The power transistors the present design are in a H' bridge configuration.

The transistor H' bridge configuration forms an electronic switch' allows bi-directional flow current to the load (motor).

Four Mosfet transistors in a H-bridge configuration form the power control switch for an individual motor.

The outputs from the comparators switch on only two of four power transistors in the H' bridge.

This is half of the switch allows current to flow to the motor in one direction.

When the opposite side of the switch' is selected The power transistors in the H' bridge form an electronic tn-state switch, the switch positions' being -1, Off 2, On -motor on in clockwise direction 3, On -motor on in counter clockwise direction The power transistors directly control the power to thruster nozzle drive motors.

When two of the selected power transistors are turned on, the motor rotates in a clockwise direction, when the two opposite transistors are turned, on the motor rotates in an anti-clockwise direction. When no transistors are turned on the motor remains in the same position.

The H-bridge switch responds to the selected direction of the joystick lever and feedback from the thrust nozzle transducer.

When activated, the motor rotates the thruster drive shaft As the drive shaft position moves, the feedback transducer sends back a signal of changing voltage, when the comparator receives a voltage at the same level as the joystick transducer, the power transistor switch turns off and the motor position remains at the same position selected by the joystick.

As the thrust nozzle is rotated by the motor, water is ejected in the required direction set by the joystick lever, propelling the craft in said direction.

4, Voltage regulation A monolithic voltage regulator is used to keep the electronic control system at a stable voltage.

Surge arresting capacitors and zener diodes are used to suppress transient voltages.

5, Speed governing system pulsed width modulation A pulse width generator consisting of a unijunction transistor and associated components, operational amplifier buffer and Mosfet power transistor is used to control the speed of rotation of the thrust nozzle.

This is controlled by potentiometer mounted on the control tower.

A speed control system is employed to allow testing and driver training.

Overview of operation-When a joystick lever is pushed forward by the driver, the transducer voltage changes accordingly, this action turns on the selected power transistors that directs power to the motor.

As the motor and shaft rotate, the position transducer attached to the shaft outputs a changing voltage accordingly. When the compared voltages from the joystick and the thrust nozzle transducers become equal, the transistor power switch is turned off.

This system is designed so that the thrust nozzle position matches the position of the joystick lever.

Some unique properties of the water craft according to the invention: 1. Two independently controlled power driven water direction thrust nozzles, centrally mounted between front and rear of the craft, spaced at maximum distance apart within hull design.

2. New hull design to accommodate thrust nozzle spacing, a smooth hull aspect to minimise drag, to allow the high manoeuvrability afforded by the thrust nozzle direction control.

3. Electronic interface converts 90 degrees movement from full forward to full reverse of joystick movement into 180 degrees of rotation of the thrust nozzle.

4. Each nozzle has a feedback system, allowing accurate positioning of the thrust nozzle mirroring the position of the joystick lever 5. The concept is to afford rapid changes of direction, under driver control. The control system is to afford the craft 360 degrees of rotational movement, pivoted directly about the drivers position creating an extreme sport personal leisure watercraft (jet-ski)'.

Claims (18)

1. CLAIMS1. A personal watercraft or water scooter including a hull, a motor, at least one water intake, two water outlets located between the bow and stern of the hull (front and rear of the hull), at least one impeller for pumping water from the water intake(s) to the water outlets, a displaceable thrust nozzle provided at each water outlet for directing the outflow of water and rotatable through one hundred and eighty degrees (1800) with each nozzle being independently controllable by position control means for steering the craft.
2. 2. A craft as claimed in claim 1, in which each thrust nozzle is controllably rotatable by means of a respective electric motor.
3. 3. A craft as claimed in claim 2, in which the output shaft of each electric motor is connected to a thrust nozzle.
4. 4. A craft as claimed in any of claims 1 to 3, in which each nozzle is rotatable about a vertical axis or substantially vertical axis.
5. 5. A craft as claimed in any of claims 1 to 4, in which the thrust nozzles are located centrally of the hull and on opposite lateral sides of a central fore and aft axis and are normally submerged when the craft is floating on water.
6. 6. A craft as claimed in any of claims 1 to 5, in which the hull has enlargements or protuberances to accommodate each nozzle.
7. 7. A craft as claimed in any of claims 1 to 6, in which the control means for steering has left-hand and right-hand portions or individual sections which respectively control the left-hand (port) or right-hand (starboard side) nozzles.
8. 8. A craft as claimed in claim 7, in which a respective control means for steering is linked to a respective one of the two nozzles such that forward movement of a control means moves a respective one of the nozzles to direct water to the rear and rearward movement directs water to the front.
9. 9. A craft as claimed in claims 7 or 8, in which each control means has two portions each comprising a control joystick or lever and a throttle or engine speed control means such as a trigger.
10. 10. A craft as claimed in any of claims 1 to 9, in which each nozzle is pivotable/rotatable for directing outflow of water between a rearward direction through a laterally outward direction and to a forward direction for respectively carrying forward, sideways and rearward motion of the craft.
11. 11. A craft as claimed in any of claims 1 to 10, in which each thrust nozzle is substantially of the shape of an inverted dome or dish or cup shaped member rotatable in the circular orifice of the outlet nozzle and to receive water from the nozzle in its main opening with circular periphery, and has an outlet aperture in its side wall such that water is directed outwardly in a horizontal or substantially horizontal direction to propel the craft.
12. 12. A craft as claimed in any of claims Ito ii, in which two impellers are provided.
13. 13. A craft as claimed in claim 13, in which two water intakes are provided or preferably a single central one.
14. 14. A craft as claimed in any of claims ito 13, in which the position control of the steering control means functions such as to be proportional such that the rotational position of a nozzle is proportional to the position of its control lever means.
15. 15. A craft as claimed in any of claims 1 to 14, in which each nozzle has a displaceable deflection baffle optionally displaceable to deflect water emanating from its associated nozzle equally forwardly and rearwardly when the nozzle is directing water laterally or at 9Q0 to the longitudinal, forwardly/rearwardly extending axis of the craft.
16. 16. A craft as claimed in claim 15, in which the position of each displaceable baffle is controlled by means of one or two respective foot operable pedals.
17. 17. A craft as claimed in any of claims 1 to 16, wherein two position control means are provided -one for each nozzle.
18. 18. A craft substantially as herein described with reference to the accompanying drawings.