WO2006050553A1

WO2006050553A1 - A hydrofoil assembly

Info

Publication number: WO2006050553A1
Application number: PCT/AU2005/001596
Authority: WO
Inventors: Gavin Mair
Original assignee: G-Speed Research Pty Ltd
Priority date: 2004-11-15
Filing date: 2005-10-14
Publication date: 2006-05-18

Abstract

A hydrofoil assembly (10) for a marine vessel having at least two elongate hulls disposed substantially parallel to each other is disclosed. The hydrofoil assembly (10) comprises a first hydrofoil (16) extending during use between an adjacent two hulls (12, 14), a second hydrofoil (18) extending during use between the adjacent two hulls (12, 14) , and means (33, 60, 80) for controllably effecting rotation of the first and second hydrofoils (16, 18) such that during use the lift and trim of the marine vessel is selectable by a user. The first and second hydrofoils (16, 18) are disposed above lower surfaces of the first and second hulls (12, 14) .

Description

A HYDROFOIL ASSEMBLY

Field of the Invention

The present invention relates to a hydrofoil assembly for a marine vessel.

Background of the Invention

It is known to provide a marine vessel which includes two elongate generally parallel hulls and a hydrofoil assembly in the form of two hydrofoils extending between the hulls. The hydrofoils are arranged such that during use the hydrofoils impart lift to the marine vessel which causes the marine vessel to move upwards relative to the waterline thereby reducing the vessel displacement and increasing the speed.

However, the lift obtained by the hydrofoil assembly is often less than optimal for the marine vessel.

In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Summary of the Invention

In accordance with a first aspect of the present invention, there is provided a hydrofoil assembly for a marine vessel having at least two elongate hulls disposed substantially parallel to each other, said hydrofoil assembly comprising: a first hydrofoil extending during use between an adjacent two hulls; a second hydrofoil extending during use between said adjacent two hulls; and means for controllably effecting rotation of the first and second hydrofoils such that during use the lift and trim of the marine vessel is selectable by a user; the first and second hydrofoils being disposed above lower surfaces of the first and second hulls

In one arrangement, the first hydrofoil is disposed at a location generally forwardly of the elongate hulls and the first hydrofoil is of generally V-shaped configuration, with an apex of the V extending in a generally downwardly direction. The first hydrofoil may be formed by fixing two hydrofoil portions together, for example by welding.

The second hydrofoil may be disposed in a location generally rearwardly of the hulls and the second hydrofoil may be of generally linear configuration.

In one arrangement, the second hydrofoil is disposed at a location generally upwardly of the first hydrofoil.

In one arrangement, at least one of the hydrofoils includes an upper surface of generally arcuate shape and a lower surface also of generally arcuate shape, the curvature of the lower surface being shallower than the curvature of the upper surface. Each hydrofoil may include a centre block disposed between the upper and lower surfaces to maintain a desired spacing between the upper and lower surfaces. The hydrofoil may have relatively sharp elongate edges which serve to allow the foil to operate efficiently at the air/water interface and pierce the water with minimum drag during use. In one arrangement, the means for controllably effecting rotation of the hydrofoils includes a fluid pump and a hydraulic ram.

In an alternative arrangement, the means for controllably effecting rotation of the hydrofoils includes an electric motor, a worm drive, and a drive gear.

In one embodiment, the means for controllably effecting rotation of the hydrofoils includes a shaft connected to a hydrofoil, the shaft being rotatably disposed in a sleeve. A bearing which may be a maritex bearing is preferably disposed between the shaft and the sleeve.

In one arrangement, each hydrofoil has an associated end plate and each shaft has an associated mounting plate, each end plate being securely fixable to a mounting plate, for example using bolts.

In an alternative arrangement, each hydrofoil is provided with a first splined portion and each shaft is provided with a second splined portion, the first and second splined portions being engageable with each other such that rotation of the shaft effects rotation of the hydrofoil. The first splined portion may be a female splined portion and the second splined portion may be a male splined portion. The first splined portion may be engageable with the second splined portion by passing the shaft outwardly of a hull towards the second splined portion.

The hydrofoil assembly may further comprise at least one position sensor associated with a hydrofoil, the position sensor being arranged to cooperate with the hydrofoil so as to generate a signal indicative of the angular orientation of the hydrofoil. The position sensor may be arranged to generate an electrical signal indicative of - A - the angular orientation of the hydrofoil and may be disposed on the shaft. The position sensor may include a magnetized counter gear and a hall effect sensor.

The hydrofoil assembly may further comprise a control panel provided with means for visually indicating the angular orientation of one or more of the hydrofoils to a user. The visual indicating means may include light emitting elements such as LEDs which may be arranged in a linear configuration.

The visual indicating means may further comprise at least one numeric position indicator arranged to provide an indication of the angular orientation of at least one hydrofoil in numeric format .

In one arrangement, the hydrofoil assembly further comprises means for generating an audible indication indicative of the degree of rotation of a hydrofoil or of the direction of rotation of a hydrofoil.

The means for controllably effecting rotation of the first and second hydrofoils may be arranged to rotate each hydrofoil at a speed not exceeding substantially 0.1° per second.

In one embodiment, the hydrofoil assembly further comprises a rotation limiting arrangement which causes rotation of a hydrofoil to cease when the angular position of the hydrofoil reaches a predetermined boundary position. The rotation limiting arrangement may comprise a lever arranged to rotate when a hydrofoil rotates, and at least one limiting switch arranged to generate a signal when the lever contacts the limiting switch, the signal causing rotation of the hydrofoil to cease. The hydrofoil assembly may be arranged so as to facilitate storage and subsequent recall by a user of predefined settings for first and second hydrofoil orientations, for recording current settings for first and second hydrofoil orientations, and for sensing current conditions and selecting a most appropriate hydrofoil orientation predefined setting for the current conditions.

In accordance with a second aspect of the present invention, there is provided a vessel including a hydrofoil assembly in accordance with the first aspect of the present invention.

Brief Description of the Drawings

The present invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic plan view of a hull portion of a vessel including a hydrofoil assembly in accordance with an embodiment of the present invention;

Figure 2 is a diagrammatic front view of a forward hydrofoil of the hydrofoil assembly shown in Figure 1;

Figure 3 is a side view of the hull portion shown in Figure 1;

Figure 4 is a diagrammatic end view of a hydrofoil of the hydrofoil assembly shown in Figure 1;

Figure 5 is a diagrammatic end view of the hydrofoil shown in Figure 4 with the hydrofoil connected to an end plate;

Figure 6 is a diagrammatic cross-sectional view of means for controllably effecting rotation of a hydrofoil;

Figure 7 is a diagrammatic end view of the hydrofoil shown in Figure 4 with the hydrofoil connected to an alternative end plate;

Figure 8 is a diagrammatic plan view of an alternative means for effecting rotation of a hydrofoil; Figure 9 is a diagrammatic side view of the alternative rotation effecting means shown in Figure 8;

Figure 10 is a diagrammatic representation of a counter gear for a position sensor of an embodiment of a hydrofoil assembly in accordance with the present invention;

Figure 11 is a diagrammatic representation of an alternative mechanism for connecting a drive shaft of the hydrofoil assembly to a hydrofoil; Figure 12 is a diagrammatic representation of a control panel of a hydrofoil assembly in accordance with the present invention;

Figure 13 is a schematic diagram showing a circuit for providing an indication to a user of the orientation of hydrofoils of a hydrofoil assembly in accordance with the present invention, and

Figure 14 is a diagrammatic representation of a limit switch arrangement of an embodiment of a hydrofoil system in accordance with the present invention.

Description of an Embodiment of the Present Invention

Referring to the drawings, there is shown a hull portion 10 of a marine vessel, the hull portion 10 comprising a first elongate hull 12 and a second elongate hull 14 of essentially the same configuration as the first hull 12 and disposed generally parallel to the first hull 12.

Extending between the first and second hulls 12, 14 at a location generally forwardly of the first and second hulls 12, 14 is a first hydrofoil 16. Similarly, extending between the first and second hulls 12, 14 at a location generally rearwardly of the first and second hulls 12, 14 is a second hydrofoil 18. The first and second hydrofoils 16, 18 form part of a hydrofoil assembly in accordance with an embodiment of the present invention. As can be seen in Figure 2, the first hydrofoil 16 is of generally V-shaped configuration with the apex of the V facing generally downwardly of the first and second hulls 12, 14 so as to minimise slamming at speed. In this example, the first hydrofoil 16 is formed by welding two hydrofoil portions together at the apex of the V by first forming a full penetration root pass weld, then forming a weld capping. However, it will be appreciated that other arrangements for fabricating the first hydrofoil 16 are envisaged.

The second hydrofoil 18 is of generally linear configuration. However, it will be understood that the second hydrofoil 18 may also be of generally V-shaped configuration.

The first and second hydrofoils 16, 18 are disposed within a space defined by the first and second hulls 12, 14; that is, the first and second hydrofoils 16, 18 do not extend beneath lower surfaces of the first and second hulls 12, 14. In this way, the likelihood of causing damage to the foils during use is minimised.

In one arrangement, the first and second hydrofoils are disposed at locations such that the second hydrofoil 18 is higher than the first hydrofoil 16 when the vessel is disposed in a body of water. In this way, a degree of safety is provided against submersion of a front portion of the vessel should the vessel raise relative to the body of water during use.

The transverse cross-sectional shape of the first and second hydrofoils 16, 18 is shown more particularly in Figure 4. Each of the hydrofoils 16, 18 includes an upper surface 20 of generally arcuate shape, and a lower surface 22 also of generally arcuate shape, the curvature of the lower surface 22 being shallower than the curvature of the upper surface 20. Disposed between the upper and lower surfaces 20, 22 generally centrally of the hydrofoil 16, 18 is a centre block 24 which serves to maintain the desired spacing between the upper and lower surfaces 20, 22.

The upper and lower surfaces 20, 22 are fixed together and to the centre block 24 using welds 26 so as to define a generally arcuate shaped hydrofoil 16, 18 having relatively sharp edges 27, the sharp edges 27 serving to pierce the water with minimum drag.

The hydrofoil assembly in accordance with the present embodiment of the invention also includes means 33 for effecting rotation of the first and second hydrofoils 16, 18 under control of a user, as shown in Figures 5 and 6.

Each of the hydrofoils 16, 18 is fixed to an end plate 28, for example by welding, the end plate 28 serving as a flange to facilitate connection of the hydrofoil 16, 18 to a mounting plate 30 shown more particularly in Figure 6. In this example, the end plate 28 is fixed to the mounting plate 30 using bolts 32. However, it will be understood that any fixing arrangement is envisaged.

The mounting plate 30 is integral with a shaft 34 of generally cylindrical configuration, the shaft being received in a generally cylindrical sleeve 38 fixed to a hull 12, 14 of the vessel. Disposed between the shaft 34 and the sleeve 38 is a cylindrical bearing 40, in this example in the form of a maritex bearing, the bearing 40 facilitating smooth rotation of the shaft 34 relative to the sleeve 38.

Connected to the shaft 34 at an end of the shaft 34 remote from the hydrofoil 16, 18 is a drive member, in this example in the form of a drive cylinder 42 keyed to the - S -

shaft 34. However, it will be understood that other arrangements are possible, such as a spline arrangement, the important aspect being that rotation of the drive cylinder 42 effects rotation of the shaft 34 and thereby the hydrofoil 16, 18.

The drive cylinder 42 is connected to a tiller arm 44 in communication with drive means 46 arranged to effect movement of the tiller arm 44 and thereby rotation of the drive cylinder 42 under control of a user. In the present example, the drive means 46 includes a hydraulic ram, a hydraulic pump and suitable circuitry for effecting extension and contraction of the hydraulic ram under control of a user. Other arrangements are envisaged for the drive means 46, such as an electrically operated worm drive.

The rotation effecting means 33 also includes a rub washer 48 which may be formed of nylon material and a lip seal 49.

Each of the means 33 for effecting rotation of a hydrofoil 16, 18 is arranged in this example to rotate through -3° to +3° from horizontal, although it will be understood that other ranges of rotation are envisaged.

It will be understood that during use a user is able to operate the drive means 46 to cause rotation of the drive cylinder 42, rotation of one or more of the first and second hydrofoils 16, 18, and thereby increase or decrease the lift generated during forward propulsion of the marine vessel. It will also be understood that a user is able to operate the drive means 46 so as to cause appropriate rotation of the first and for second hydrofoil to modify the trim of the vessel. In a preferred embodiment, the drive means is arranged to effect gradual rotation of the first and/or second hydrofoils 16, 18, in particular so that the speed of rotation of the hydrofoils is relatively slow, for example of the order of 0.1° per second.

As shown in Figure 7, as an alternative, the end plate 28 may be fixed to an alternative mounting plate 50 of greater depth than the mounting plate 30 shown in Figures 5 and 6. This arrangement allows for a lower foil position than is achieved with the mounting plate 30 shown in Figures 5 and 6.

An alternative mechanism 60 for effecting rotation of a hydrofoil 16, 18 is shown in Figures 8 and 9. Like and similar features are indicated with like reference numerals.

The alternative rotation effecting mechanism 60 includes an electric motor 62 which when activated effects rotation of a worm drive 64. The worm drive 64 meshes with a drive gear 66 fixedly mounted on a drive shaft 68. The drive shaft 68 is rotatably mounted in a mounting bearing 70 fixedly disposed on an inside surface of a vessel hull 12, 14.

In this example, as shown in Figure 11, an alternative mechanism for connecting the drive shaft 68 to a hydrofoil 16, 18 is used. Instead of providing an end plate and a corresponding mounting plate which fit together using bolts, the drive shaft 68 is provided with a male splined portion 72 and the hydrofoil 16, 18 is provided with a female splined portion 74 arranged to engagingly receive the male splined portion 72 such that rotation of the drive shaft 68 effects rotation of the hydrofoil 16, 18. - li ¬ lt will be understood that by using such a splined arrangement, it is possible to connect the hydrofoil 16, 18 to the drive shaft 68 simply by aligning the female splined portion 74 with the mounting bearing 70 and guiding the drive shaft 68 through the mounting bearing 70 and into engagement with the female splined portion 74.

In order to provide feedback as to the angular orientation of the hydrofoils 16, 18, each hydrofoil 16, 18 has an associated position sensor 76, in this example mounted on an end of the drive shaft 68 remote from the hydrofoil 16, 18. In this embodiment, the position sensor 76 includes a magnetised counter gear 77 shown in Figure 10 which cooperates with a hall effect sensor (not shown) so as to provide a pulsed electrical signal when the counter gear 77 rotates. The arrangement is such that rotation of the drive shaft 68 causes the counter gear 77 to rotate and the position sensor 76 to generate an electrical signal indicative of the angular position of the drive shaft 68 and thereby of the hydrofoil 16, 18.

The electrical signals generated by the position sensors 76 are supplied to a control panel 80 as shown in Figure 12, the control panel 80 providing visual information to a user as to the orientation of the hydrofoils 16, 18 and including controls which enable a user to adjust the angular orientation of the hydrofoils 16, 18. For this purpose, the control panel 80 includes LED position indicators 82 which are arranged in a linear configuration adjacent a scale, illumination of a particular LED 82 relative to the scale providing an indication as to the angular orientation of the hydrofoil 16, 18. The control panel 80 also includes numeric position indicators 84 which provide an indication of the angular orientation of the hydrofoils 16, 18 in numeric format and to a greater degree of detail than is possible with the LED position indicators 82. The brightness level of the LEDs may be adjustable so as to suit daytime or nighttime ambient light conditions.

The control panel 80 also includes forward and aft buttons 86 and 88 respectively, the forward button 86 being used to selectively effect rotation of the first hydrofoil 16 and the aft button 88 being used to selectively effect rotation of the second hydrofoil 18. The forward button 86 is connected in circuit with the electric motor 62 associated with the first hydrofoil 16, and the aft button 88 is connected in circuit with the electric motor 62 associated with the second hydrofoil 18. In this way, operation of the forward or aft buttons 86, 88 effects appropriate forward or reverse activation of the relevant electric motor 62 and thereby forward or reverse rotation of the relevant first or second hydrofoil 16, 18.

The control panel 80 may also be associated with an audio generation device arranged to generate audible indications indicative of the degree of rotation of the hydrofoils, whether a hydrofoil is being rotated in a forwards or backwards direction, and so on. For example, in one arrangement the audio generation device is arranged to generate a first audible signal when a hydrofoil is rotated in a forwardly direction and to generate a second different audible signal when the hydrofoil is rotated in a rearwardly direction. The audible signals generated for the first and second hydrofoils when moved in a forwardly or rearwardly direction may also be different.

An example of a feedback circuit 89 useable to provide a visible and/or audible indication as to the angular orientation of the first and second hydrofoils 16, 18 is shown in Figure 13. The feedback circuit 89 in this example includes first and second LED drivers 90, 92, each of which is arranged to cause selective activation of LEDs 94. In this example, each of the first and second LED drivers 90, 92 is an LM3914 integrated circuit arranged to cooperate with a series of ten LEDs 94 so that one or more appropriate LEDs 94 are illuminated depending on the magnitude of an input voltage signal received from a position sensor 76. Each of the first and second hydrofoils 16, 18 has associated first and second LED drivers 90, 92 and associated LEDs 94.

As shown in Figure 14, the hydrofoil assembly may further comprise a rotation limiting arrangement 100 which in this example comprises a lever 102 attached to the drive shaft 68 such that rotation of a hydrofoil and thereby a drive shaft 68 causes rotation of the lever 102. The rotation limiting arrangement comprises limit switches 104 disposed at either side of a remote end 106 of the lever 102, the limit switches cooperating with the lever 102 so as to cause rotation of a hydrofoil to cease when the remote end 106 contacts a limit switch 104. This ensures that rotation is only permitted within predefined boundaries.

It will be appreciated that since the angular orientation of the first and second hydrofoils 16, 18 is controlled by applying electric signals to electric motors 62 associated with the first and second hydrofoils 16, 18, it is possible to store and subsequently recall predefined settings for first and second hydrofoil positions. In this way, a user would be able to reproduce particular first and second hydrofoil orientations using appropriate controls on the control panel 80 so as to quickly and easily tailor the orientations of the hydrofoils 16, 18 to suit current conditions.

The hydrofoil assembly may also include a mechanism for recording current settings for first and second hydrofoil angular orientations, and for subsequently recalling the settings as desired. The hydrofoil assembly may also be arranged to automatically select predefined presets for hydrofoil orientations by sensing current conditions and selecting the most appropriate hydrofoil orientation preset for the current conditions.

It will be appreciated that the hydrofoil assembly of the present invention enables a user to tailor the lift and trim of a vessel to suit the particular vessel and current conditions.

It will also be appreciated that by including the present hydrofoils in a vessel, the speed of the vessel can be increased by 5 knots or more compared to a similar vessel without hydrofoils.

It will also be appreciated that by providing a vessel with the present hydrofoils, fuel and operational costs are reduced relative to a vessel without such hydrofoils.

Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

Claims

CLAIMS :

1. A hydrofoil assembly for a marine vessel having at least two elongate hulls disposed substantially parallel to each other, said hydrofoil assembly comprising: a first hydrofoil extending during use between an adjacent two hulls; a second hydrofoil extending during use between said adjacent two hulls,- and means for controllably effecting rotation of the first and second hydrofoils such that during use the lift and trim of the marine vessel is selectable by a user; the first and second hydrofoils being disposed above lower surfaces of the first and second hulls.

2. A hydrofoil assembly as claimed in claim 1, wherein the first hydrofoil is disposed at a location generally forwardly of the elongate hulls and the first hydrofoil is of generally V-shaped configuration, with an apex of the V extending in a generally downwardly direction.

3. A hydrofoil assembly as claimed in claim 1 or claim 2, wherein the second hydrofoil is disposed at a location generally rearwardly of the hulls and the second hydrofoil is of generally linear configuration.

4. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the first hydrofoil is disposed in a location generally forwardly of the elongate hulls, the second hydrofoil is disposed in a location generally rearwardly of the elongate hulls, and the second hydrofoil is disposed in a location generally upwardly of the first hydrofoil .

5. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the means for controllably effecting rotation of the hydrofoils includes a fluid pump and a hydraulic ram.

6. A hydrofoil assembly as claimed in any one of claims 1 to 4, wherein the means for controllably effecting rotation of the hydrofoils includes an electric motor, a worm drive and a drive gear.

7. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the means for controllably effecting rotation of a hydrofoil comprises a drive shaft provided with a first splined portion, and the hydrofoil is provided with a second splined portion, the first and second splined portions being engageable with each other such that rotation of the shaft effects rotation of the hydrofoil, and the first splined portion being engageable with the second splined portion by passing the drive shift outwardly of a hull towards the second splined portion.

8. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the hydrofoil assembly comprises at least one position sensor associated with a hydrofoil, the position sensor being arranged to generate a signal indicative of the angular orientation of the hydrofoil.

9. A hydrofoil assembly as claimed in claim 8, wherein the position sensor includes a magnetised counter gear and a hall effect sensor.

10. A hydrofoil assembly as claimed in claim 8 or claim 9, wherein the hydrofoil assembly comprises a control panel provided with means for visually indicating the angular orientation of one or more of the hydrofoils to a user.

11. A hydrofoil assembly as claimed in claim 10, wherein the visual indicating means include a plurality of light emitting elements arranged in a linear configuration.

12. A hydrofoil assembly as claimed in any one of the preceding claims, further comprising means for generating an audible indication indicative of the degree of rotation of a hydrofoil or of the direction of rotation of a hydrofoil.

13. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the means for controllably effecting rotation of the first and second hydrofoils is arranged to rotate each hydrofoil at a speed not exceeding substantially 0.1° per second.

14. A hydrofoil assembly as claimed in any one of the preceding claims, further comprising a rotation limiting arrangement which causes rotation of a hydrofoil to cease when the angular position of the hydrofoil reaches a predetermined boundary position.

15. A hydrofoil assembly as claimed in claim 14, wherein the rotating limiting arrangement comprises a lever arranged to rotate when a hydrofoil rotates, and at least one limiting switch arranged to generate a signal when the lever contacts the limiting switch, the signal causing rotation of the hydrofoil to cease.

16. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the hydrofoil assembly is arranged so as to facilitate storage and subsequent recall by a user of predefined settings for first and/or second hydrofoil orientations.

17. A hydrofoil assembly as claimed in claim 16, wherein the hydrofoil assembly is arranged so as to facilitate recording of current settings for first and/or second hydrofoil orientations.

18. A hydrofoil assembly as claimed in any one of the preceding claims, wherein the hydrofoil assembly is arranged to sense current conditions and to select a most appropriate hydrofoil orientation setting for the current conditions.

19. A vessel including a hydrofoil assembly as claimed in any one of the preceding claims.