GB2099113A - Amphibious vehicle with hydrostatic drive - Google Patents

Abstract

An amphibious vehicle particularly for recreational purposes driven by a small diesel engine (11) which powers an hydraulic system. A tandem pump (12) supplies hydraulic fluid to separate left and right hydraulic motors which drive via chains (19), sets of road wheels and (via clutches 20) left and right propellers (43). Steering is effected by controlling the flow of fluid to the hydraulic motors by reversing valves (451). The vehicle is also equipped with a compressor (26), a bilge pump (41) and a winch (28). <IMAGE>

Description

SPECIFICATION Water and land automobile Background of the Invention The present invention relates to an amphibious vehicle and in particular to an amphibious recreational vehicle.

Amphibious vehicles in general are known, however such vehicles are typically heavy militarytype vehicles or have not been suitable for off the road rough terrain usage. Further prior art amphibious vehicles have typically been driven by diesel or gasoline engines, mechanically coupled to the drive train through a transmission.

Summary of the Invention The present invention provides a vehicle comprising a body; right and left sets of wheels respectively disposed on the right and left sides of said body; respective right and left hydraulic pumps; means for driving said right and left hydraulic pumps; means for providing a supply of hydraulic fluid to said right and left hydraulic pumps; right and left hydraulic motors; first conduit means for providing an hydraulic fluid path between said right hydraulic motor and said right hydraulic pump; second conduit means for providing an hydraulic fluid path between said left hydraulic motor and said left hydraulic pump; a right drive gear operatively connected to said right hydraulic motor; a left drive gear operatively connected to said left hydraulic motor; means associated with said right hydraulic pump for independently controlling the hydraulic fluid flow to said right hydraulic motor to controllably effect rotation of said right drive gear; means associated with said left hydraulic pump for independently controlling the hydraulic fluid flow to said left hydraulic motor to controllably effect rotation of said left drive gear; right transmission means cooperating with said right drive gear and said right set of wheels for imparting rotational motion to said wheels in accordance with rotation of said right drive gear; and left transmission means cooperating with said left drive gear and said left set of wheels for imparting rotational motion to said left set of wheels in accordance with rotation of said left drive gear.

More particularly an amphibious vehicle in accordance with the present invention provides a highly efficient multi-purpose amphibious vehicle suitable for street driving off the road rough terrain driving and water surface usage. A relatively small diesel engine is utilised to power an hydraulic system which in turn provides both motive force and steering for the vehicle. A tandem pump powered by the diesel engine controllablysupplies hydraulic fluid to left and right hydraulic motors.

The hydraulic motors are coupled by continuous chain transmissions to respective sets of wheels disposed on the respective sides of the vehicle.

Respective propellers are also coupled to the hydraulic motors through a magnetic clutch.

Steering is effected by selectively controlling the fluid flow to the respective hydraulic motors. Thus, a particularly efficient and inexpensive drive system and steering system is provided.

Brief Description of the Drawings A preferred embodiment of the present invention will now be described by way of example only in conjunction with the accompanying drawings wherein like numerals denote like elements.

FIGURES 1 a, 1 b, 1 c and id are respectively top, side, front and rear views of an emphibious vehicle in accordance with the present invention.

FIGURE 2 is a schematic block diagram of the drive system of the vehicle of the present invention.

FIGURE 3 is a diagrammatic illustration of the drive system of Figure 2.

FIGURE 4 is a schematic view illustrating driver control levers and linkage.

FIGURE 5 is a diagrammatic view of a portion of the drive system of Figure 2, and FIGURE 6 is a schematic diagram of a chain drive transmission in accordance with one aspect of the present invention.

Detailed Description of the Preferred Embodiment Referring first to Figures 1 a to 1 a, an amphibious vehicle 10 in accordance with the present invention includes a pontoon shaped water tight body (chassis) 100. Wheels 31, 32 and 33 are independently mounted to the left side of body 100. Similarly, wheels 34, 35 and 36 are mounted to the right side of the vehicle. Wheels 31, 32, 33, 34, 35 and 36 suitably include tyres having protruding tread bars to facilitate traction in rough terrain and to provide a motive force in water. Left and right propellers 43L and 43R respectively are provided at the lower rear of vehicle 10, in addition a winch 28 is provided at the front end of vehicle 10.

The elements of vehicle 10 will now be described with reference to Figures 2 and 3.

Figure 2 shows the respective elements of the system in block diagram form, whereas Figure 3 provides a pictorial illustration of the elements showing their relative disposition in vehicle 10.

Support structures are omitted from Figure 3 for the sake of clarity and ease of illustration.

Motive power and steering for vehicle 10 is provided by a hybrid diesel/hydraulic system.

A diesel engine 11 having a co-operating fuel tank 1 7 and accelerator control pedal 42, is mechanically coupled by a shaft 47 to a conventional tandem pump 12. Tandem pump 12 co-operates with an hydraulic fluid (oil) reservoir 1 5. Fluid from reservoir 1 5 is forced by an auxiliary feed pump 14 through a filter 25, into the input of tandem pump 12.

Tandem pump 12 comprises, in effect, two independently controlled pumps connected in tandem and provides independent output flows of hydraulic fluid in accordance with respective control valves 451 and 451 R. Control valves 451 and 451 Rare respectively coupled by linkage arms 45L and 45R to control levers 1 8L and 18R. The linkage between control levers 18 and control valves 451 will be more fully explained in conjunction with Figure 4.

The outputs of tandem pump 12 are coupled to respective hydraulic motors 1 3L and 1 3R disposed on the left and right sides of the vehicle.

The hydraulic system will hereinafter be more fully explained in conjunction with Figure 5.

Hydraulic motors 1 3L and 1 3R are coupled through respective continuous chains 1 9L and 1 9R to the wheels of the associated side of the vehicle. The chain transmission system will hereinafter be more fully described in conjunction with Figure 6.

Propellers 43L and 43R are selectively connected into the transmission system by respective magnetic clutches 20L and 20R.

Electric power for magnetic clutches 20 is provided by a battery 16. Battery 1 6 is suitably connected to a generator or alternator (not shown) associated with the diesel engine 11.

In addition, an air compressor 26 and water pump 41 are provided in vehicle 10. Air compressor 26 is suitably belt driven by tandem pump 12. Water pump 41 may be electric or may be selectively coupled into the hydraulic system (connections not shown). Winch 28 is suitably hydraulically driven by tandem pump 12 (connections not shown in Figure 3).

As will hereinafter be explained, steering of vehicle 10 is effected by selective operation of control levers 1 8L and 18R. Control levers 1 8 in co-operation with control valves 451 control the flow of hydraulic fluid to hydraulic motors 1 3L and 13R.

Referring to Figure 4, control levers 1 8 are pivotally mounted on the floorboard 602 of vehicle 10. As previously noted, control levers 18 are coupled to control valves 451 by respective linkage arms 45. Control arms 1 8 are biased to a neutral or "off" position by respective springloaded hydraulic cylinders 45aL and 45aR (only 45aL shown).

Referring now to Figure 5, the drive/steering system will be described. As noted above, hydraulic motors 1 3L and 1 3R are driven by the hydraulic fluid selectively supplied by tandem pump 12. Motors 13 can rotate either in a forward or reverse direction and provide high torque at low speeds of revolution. Considering now only the left side of the vehicle, tandem pump 12 selectively establishes fluid communication with hydraulic motor 1 3L through conduits 21 and 22. Conduits 21 and 22 are suitably a flexible hose although rigid conduits can be utilised if desired. The direction of fluid flow through conduits 21 and 22 is controlled by control vaive 451 L in accordance with the position of control lever 1 8L.When control lever 1 8L is in a position forward of the neutral position, pump 12 forces fluid through conduit 21 to motor 1 3L and receives return fluid through conduit 22 to establish a forward rotation of a gear 1 30L cooperating with motor 13L. When control lever 1 8L is in the neutral position, fluid flow to motor 13L is cut off. Conversely, when control 1 8L is pulled to a position to the rear of the neutral position, a reverse flow of hydraulic fluid to motor 1 3L is effected. That is, hydraulic fluid is forced through conduit 22 to the motor 13 and returned to pump 12 through conduit 21 to establish a reverse rotation (clockwise as seen in Figure 6) of gear 1 30L. The right side of the vehicle works in a similar manner.

The hydraulic fluid for tandem pump 12 is provided from a reservoir 1 5. The fluid is withdrawn from reservoir 1 5 through a suitable filter 25 by feed pump 14 and provided through a conduit 23 to the respective right and left portions of tandem pump 12. The return fluid to the respective portions of tandem pump 12 is passed through a conduit 271 to a suitable heat exchanger/cooler 27. The cooled fluid is then directed through a conduit 24 back towards reservoir 1 5.

As will hereinafter be explained in conjunction with Figure 6, gears 130L and 130R comprise a portion of a continuous chain drive transmission system. Clockwise rotation of the motor gear 130 causes the associated wheels to rotate in a counter-clockwise direction and vice versa. Thus, by manipulating control levers 1 8L and 1 8R the vehicle operator can control movement of vehicle 10. For example, by pulling back on both control levers 1 8L and 18R, a forward motion of the vehicle is effected. Similarly, by pushing both control levers 1 8L and 1 8R forward, vehicle 1.0 is made to move in a reverse direction.By selectively operating one or the other of control levers 1 8L or 18R, or pushing one forward while pulling on the other, right and left turns of the vehicle of varying degree can be effected.

Referring now to Figure 6, the chain transmission in accordance with the present invention will be described. Only the left side chain transmission will be described since the right side is similar.

As noted above, hydraulic motor 1 3L controllably imparts a rotational motion to gear 130L. Hydraulic motor 13 and gear 1 30L are disposed above the respective wheel axles between the central and rear wheel (supporting members not shown). Gear 1 30L engages a continuous chain 19L. Chain 1 9L also engages respective gears 31a, 32a and 33a, fixed on the axles of wheels 31, 32a and 33a, are engaged by the interior side of chain 1 9L while gear 1 30L engages the outer side of the chain. More specifically, the outer surface of chain 1 9L engages gear 1 30L and the inner surface of the chain thereafter engages in sequence gear 31 a, movable gear 54, gear 33a and gear 32a, then returns to drive gear 130L.

Movable gear 54 comprises a portion of a chain tension control mechanism 500. Movable gear 54 is mounted on a pivotally mounted crank 51 cooperating with a threaded rod 52 and adjustment nut 53. Crank 51 is mounted on a pivot 55 fixed to the chassis 100 by suitable support means (not shown). Crank 51 co-operates with the threaded rod 52 and adjustment nut 53 such that tightening nut 53 causes a downward motion on one end of crank 51. The downward motion causes a pivotal action raising movable gear 54 and thus increasing tension on chain 19L. Chain tensioning mechanism 500 is suitably disposed at the rear of chassis 100 as shown in Figure 6 with movable gear 54 disposed slightly above gear 130L to allow the path of transmission chain 1 9L to remain in a single plane.However, tension adjusting mechanism 500 can also be disposed in the forward part of chassis 100 as illustrated in Figure 3. In that instance, the normal disposition of movable gear 54 is such that the chain clears gear 1 30L in traversing between movable gear 54 and gear 33.

The particular chain transmission shown wherein driving gear 1 30 is disposed above gears 31 a, 32a and 33a, between the central and rear wheels is particularly advantageous in that it provides greater wraparound of the respective gears by chain 19L. Gears 31 a, 32a and 33a are suitably within waterproof chassis 100 and the axles of the wheels extend through chassis 100.

The shaft of the wheel is provided with an oil seal (not shown) to maintain a watertight chassis.

It should be appreciated that the above described embodiment provides a particularly advantageous amphibious vehicle. The hydraulic drive system in co-operation with the chain transmission system provides a particularly light and efficient drive mechanism. Moreover, the hydraulic drive system and independent chain transmissions provide an inexpensive mechanism for steering the vehicle. Propellers 43L and 43R provide for additional motive power when in water. Pump 41 also provides for eliminating any water shipped by vehicle 10. In addition, air compressor 26 (Figure 3) provides an air source for inflating life saver buoys and the like and for inflating tyres 31.32. 33. 34, 35 or 36 when necessary in particularly rough terrain (or inflating the tyres after deflation has been necessary).

Winch 26 is utilised in effect as an auxiliary motive power force in particularly rough terrain. More particularly, winch 28 can be utilised to pull vehicle 10 out of mud or on to a dock.

It will be understood that various support structures and auxiliary systems, e.g. a brake system, have been omitted from the description for the sake of clarity. In respect of the brake system, it should be noted that braking can be accomplished by reversing the direction of hydraulic motors 13L and 13R. However, an auxiliary braking system may be provided if desired.

It will be understood that the above description is of a preferred embodiment of the present invention and that the invention is not limited to the specific form shown.

Claims (9)

1. A vehicle comprising: a body; right and left sets of wheels respectively disposed on the right and left sides of said body; respective right and left hydraulic pumps; means for driving said left and right hydraulic pumps; means for providing a supply of hydraulic fluid to said right and left hydraulic pumps; right and left hydraulic motors; first conduit means for providing a hydraulic fluid path between said right hydraulic motor and said right hydraulic pump; second conduit means for providing a hydraulic fluid path between said left hydraulic motor and said left hydraulic pump; a right drive gear operatively connected to said right hydraulic motor; a left drive gear operatively connected to said left hydraulic motor;; means associated with said right hydraulic pump for independently controlling the hydraulic fluid flow to said right hydraulic motor to controllably effect rotation of said right drive gear; means associated with said left hydraulic pump for independently controlling the hydraulic fluid flow to said left hydraulic motor to controllably effect rotation of said left drive gear; right transmission means, co-operating with said right drive gear and said right set of wheels, for imparting rotational motion to said wheels in accordance with rotation of said right drive gear; and left transmission means, co-operating with said left drive gear, and sad left set of wheels, for imparting rotational motion to said left set of wheels in accordance with rotation of said left drive gear.

2. The vehicle of Claim 1 wherein said body is substantially watertight and said vehicle further comprises a right propeller and a left propeller, both disposed at the rear of said body; first clutch means, for selectively coupling said right propeller to said right transmission whereby rotational motion is imparted to said right propeller in accordance with the rotation of said right drive gear; and left clutch means for selectively coupling said left propeller to said left transmission means whereby rotational motion is imparted to said left propeller in accordance with rotation of said left drive gear.

3. The vehicle of Claim 1 or Claim 2 wherein said right and left transmission means each comprises a respective gear operatively connected to each of the associated set of wheels, and a continuous chain engaging each of said gears and the associated drive gear.

4. The vehicle of Claim 3 wherein said drive gear engages the outer surface of said continuous chain, and said respective gears each engages the inner surfce of said continuous chain.

5. The vehicle of Claim 4 wherein said drive gear is disposed above said gears.

6. The vehicle of Claim 3 wherein said transmission further includes tension adjustment means including a movable gear engaging the inner surface of said continuous chain, and means for adjusting the relative position of said movable gear.

7. The vehicle of Claims 1, 2 or 3 further including a winch disposed on the front of said body and operatively coupled to at least one of said right and left hydraulic pumps.

8. The vehicle of Claims 1 , 2 or 3 wherein said means for driving said right and left hydraulic pumps comprises a diesel engine.

9. A vehicle substantially as herein described with reference to the accompanying drawings.