Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60F—VEHICLES FOR USE BOTH ON RAIL AND ON ROAD; VEHICLES CAPABLE OF TRAVELLING IN OR ON DIFFERENT MEDIA, e.g. AMPHIBIOUS VEHICLES
  • B60F3/00—Amphibious vehicles, i.e. vehicles capable of travelling both on land and on water; Land vehicles capable of travelling under water
  • B60F3/0007—Arrangement of propulsion or steering means on amphibious vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60F—VEHICLES FOR USE BOTH ON RAIL AND ON ROAD; VEHICLES CAPABLE OF TRAVELLING IN OR ON DIFFERENT MEDIA, e.g. AMPHIBIOUS VEHICLES
  • B60F2301/00—Retractable wheels
  • B60F2301/04—Retractable wheels pivotally

Definitions

• the present invention relates to an amphibious vehicle having a hull conformed to enable planing.
• an amphibious vehicle in accordance with the invention which has a hull confirmed to enable planing, road wheels with drag reduction means and at least one marine propulsion unit, is provided with an engine having an engine output shaft aligned fore and aft and arranged to drive a gearbox having a reversible output, this reversible output arranged to drive at least some of the road wheels and the marine propulsion unit, wherein the reversible output is arranged to drive the road wheels through a differential located between the engine and gearbox.
• the drag reduction means may be either fairings for the wheels, or preferably retractable wheels.
• the provision of the differential between the engine and gearbox ensures the centre of gravity of the power train is kept as low as possible. Hence the vehicle has a low metacentric height, which is important for stability.
• the position of the differential between engine and gearbox also assists packaging by ensuring that the differential does not intrude into the area where the marine drive and water intake are located for an aft-mounted water jet.
• the provision of a reversing drive to the marine propulsion unit is effective in reducing drag, as it is not essential to fit a reversing bucket.
• Figure 1 is a diagrammatic side view of a vehicle according to the invention with wheel fairings or retraction;
• Figure 2 is a plan sectional view of the vehicle of Figure 1;
• Figure 3 is a longitudinal sectional view of the arrangement of engine, gearbox, road wheel and marine drive for the vehicle of Figure 1;
• Figure 4 is a cross section of the vehicle of Figure 2 taken on line IV - IV of that figure, showing the disposition of engine and retractable wheels;
• Figure 5 is a similar cross section to Figure 4, showing the same disposition of engine and retractable wheels, but for a second embodiment with the engine having one or more canted bank(s) of cylinders;
• Figure 6 is a plan sectional view similar to Figure 2, showing an alternative power train and interior seating layout according to the second embodiment of Figure 5;
• Figure 7 shows diagrammatically a vehicle being a third embodiment of the invention.
• Figure 8 shows diagrammatically a vehicle being a fourth embodiment of the invention.
• an amphibious vehicle 1 having retractable front wheels 2 and retractable rear wheels 3; or as shown in broken lines at 12 and 13, retractable fairings.
• the wheel retraction or fairings constitute drag reduction means.
• Vehicle 1 has a hull 4 conformed for planing, to which end the engine 18 with its associated reversible gearbox 63 are mounted towards the rear of the vehicle.
• the engine is mounted just in front of the rear axle; this is known as a mid- engine configuration; or as a mid-mounted engine. It will also be noted that the engine is mounted North-South, that is, with the flywheel towards the rear of the vehicle.
• transaxle differential 24 Driven from gearbox 63 (see Figure 3) through gears 46 on input shaft 44, and gears 48 on output shaft 50, are transaxle differential 24 and marine propulsion unit 40 with impeller 38.
• the impeller is driven from gearbox 63 by synchromesh unit 65 in housing 61.
• Unit 65 functions as a decoupler to decouple drive gear 58, which is coupled to the impeller 38 by driveshaft 36 and constant velocity joint 56.
• decouplers 70 ( Figures 4 and 5) are provided for halfshafts 72.
• Figure 4 shows a cross section of the vehicle, and particularly the conformation of the planing hull 4.
• the engine 18 is mounted as low as possible to improve die marine stability.
• a particular advantage of a longitudinally mounted engine in a planing vehicle may be seen from this figure.
• the hull In a planing vehicle, the hull must have a deadrise to allow planing; that is, the two sides of the hull slope upwards from a low point on the longitudinal centre line.
• a longitudinal engine can be mounted lower in the vehicle than a transverse engine, because the engine sump - conventionally the lowest point on the engine - can be fitted into the lowest part of the hull.
• the sump With a transverse engine layout, as shown for example in the applicant's co-pending application published as WO 02/07999, the sump must be mounted or adapted to clear the deadrise of the hull.
• the centre of gravity of the power train, and therefore of the vehicle is made as low as possible, with beneficial effects on roadholding and on-road handling and stability.
• the determinant of vehicle stability is metacentric height - the vertical distance between the centre of gravity and the centre of buoyancy, discussed at length in WO 02 07999. The greater this height, the more stable the vehicle.
• Figure 5 shows a second embodiment of the amphibious vehicle according to the invention, with a further refinement to improve vehicle stability.
• the engine block 18' is canted to one side to lower the centre of gravity, and increase the metacentric height, still more than with a power train laid out according to Figure 4.
• An engine 18" with a second canted cylinder bank ⁇ that is, a vee type engine - has a lower centre of gravity than an upright, inline engine; and will usually be shorter than an inline engine for the same power output.
• a 2.5-litre V6 engine may develop 170PS with a shorter cylinder block and shorter piston, stroke than an inline 2.0- litre four cylinder developing 140PS.
• the four-cylinder engine would have to be supercharged or turbocharged.
• such forced induction can lead to heat dissipation problems on water, due to the lack of ram air effect, and the sealing of the underside of the engine bay necessary to ensure flotation.
• seat 16 may be a centrally mounted driver's seat. This layout gives a commanding view on water, and obviates the need to tool up for separate left- and right-hand drive versions of the amphibious vehicle. In a racing amphibious vehicle, seat 16 may be the only one fitted.
• Figure 7 shows a third embodiment of the amphibious vehicle according to the invention.
• Vehicle 91 is essentially an amphibious bus, with several rows of seating 17, and retractable wheels 2' and 3' fore and aft.
• Engine 18 is mounted beneath the passenger compartment floor, as is known from land-based buses and coaches. In such a vehicle, a low engine height is helpful not only to lower the centre of gravity, but also to allow the lowest possible passenger floor. By containment of the entire power train within the rear part of the vehicle, there are two options for seating and luggage space.
• rows of seating 17 may be mounted on the level, and space 92 used for luggage; alternatively, theatre type seating may be fitted, with the fo ⁇ emost seats low down and the rearmost seats highest, to allow the passengers at the back of the vehicle to see out forwards. In either case, the shorter and lower the engine the better; so a canted engine 18'according to Figure 5, or a vee type engine 18" corresponding to Figures 5 and 6, will be found particularly suitable for this vehicle.
• Figure 8 shows a narrow amphibious vehicle 101, with one or more retractable front wheels 2", and retractable rear wheels 3".
• a narrow amphibious vehicle 101 With one or more retractable front wheels 2", and retractable rear wheels 3".
• two rear wheels are needed; and so in turn, a differential is required.
• the width of the vehicle particularly where there is only a single front wheel, is such that there is room for only one seat across the vehicle.
• the Figure shows tandem type seating, with a passenger located behind the driver. Such seating would conventionally be on or adjacent to the longitudinal centre line of the vehicle. In this embodiment, there is clearly a compromise between seating height and the width of the engine bay.
• an engine such as the Volkswagen VR6 engine, with a fifteen degree angle between its cylinder banks, is shorter than an inline six, but narrower than a conventional V-6 engine, with an angle of sixty or even ninety degrees between its banks.
• Packaging studies have shown that a vee angle of as little as ten degrees between two cylinder banks can be beneficial in packaging the power train and vehicle occupant or rider accommodation.
• a cylinder bank angle of as little as five degrees from the vertical can be beneficial to packaging.
• any or all of the decouplers described above may comprise a constant velocity joint and synchromesh unit, as described in the applicant's co-pending application, published as WO 02/14092.
• the wheel driveshafts may also be decoupled by one decoupler only; as the other halfshaft may be locked by use of the vehicle handbrake on water.
• a mid engined layout is described, a front mounted engine could be used if a suitable weight distribution for planing could be achieved.
• a four wheel drive layout could be provided by a suitable power take off or transfer case from the transmission.
• a flat engine that is one having opposed horizontal banks of cylinders, could be used; although difficulties can be foreseen with maintenance access, and with routing of exhaust pipes and/or fuel and air inlet piping.
• a propeller marine drive, or twin jet drive could be arranged. Where a central driving position is provided, a seat mounting arrangement according to the applicant's co- pending application OB0218604.7 may be found beneficial.
• a manual gearbox is shown in the figure, a semi-automatic, fully automatic, or CVT (continuously variable transmission) may be found equally suitable for both road and marine purposes.
• CVT continuously variable transmission

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Arrangement Or Mounting Of Propulsion Units For Vehicles (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9943213

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (8)

Family Cites Families (11)

• 2002
  • 2002-08-30 GB GB0220164A patent/GB0220164D0/en not_active Ceased
• 2003
  • 2003-08-29 EP EP03773830A patent/EP1581402A1/de not_active Withdrawn
  • 2003-08-29 WO PCT/GB2003/003787 patent/WO2004020228A1/en not_active Ceased
  • 2003-08-29 AU AU2003282210A patent/AU2003282210A1/en not_active Abandoned
  • 2003-08-29 GB GB0320374A patent/GB2392415A/en not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events